A Large Randomized Individual and Group Intervention Conducted by Registered Dietitians Increased Adherence to Mediterranean-Type Diets: The PREDIMED Study

A Mediterranean dietary pattern intervention does not improve cardiometabolic risk but does improve quality of life and body composition in an Aotearoa New Zealand population at increased cardiometabolic risk: A randomised controlled trial

AIMS

To test if a New Zealand food-based Mediterranean diet (NZMedDiet) with behavioural intervention improves cardiometabolic health and wellbeing.

METHODS

A randomised controlled trial comparing 12 weeks of the NZMedDiet to usual diet in participants with increased cardiometabolic risk (metabolic syndrome severity score [MetSSS] > 0.35). The intervention group was provided with food and recipes to meet 75% of their energy requirements, supported by a behavioural intervention to improve adherence. The primary outcome measure was (MetSSS) after 12 weeks.

RESULTS

Two hundred individuals with mean (SD) age 49.9 (10.9) years of which 62% women were enrolled with their household/whānau. After 12 weeks, the mean (SD) MetSSS was 1.0 (0.7) in the control (n = 98) and 0.8 (0.5) in the intervention (n = 102) group; estimated difference (95% confidence interval [CI]) of -0.05 (-0.16 to 0.06), p = 0.35. The Mediterranean diet score (PyrMDS) was greater in the intervention group 1.6 (1.1-2.1), p < 0.001, consistent with a change to a more Mediterranean dietary pattern. Weight reduced in the NZMedDiet group compared with control (-1.9 kg [-2.0 to -0.34]), p = 0.006 and wellbeing, assessed by the SF-36 quality of life questionnaire, and improved across all domains. For example, the physical component summary score difference (95% CI) was 4.0 (2.4-5.7), p < 0.001, and the mental component summary score difference was 3.0 (0.7-5.2), p = 0.01.

CONCLUSION

In participants with increased cardiometabolic risk, food provision with a Mediterranean dietary pattern and a behavioural intervention did not improve metabolic risk scores but was associated with reduced weight and improved quality of life.

Influence of a structured, 1-year-long dietary intervention regarding body composition and cardiovascular risk (ARCTIC) in coeliac disease: a protocol of a multicentre randomised controlled trial

INTRODUCTION

Coeliac disease (CD) affects 1% of the population worldwide. The only available evidence-based treatment is a strict gluten-free diet (GFD), which can readily lead to weight gain and unfavourable metabolic changes (eg, dyslipidaemia, fatty liver disease and insulin resistance) if followed without adequate dietary control. That can lead to increased cardiovascular risk (CV). We planned a randomised controlled trial to test the effect of a group-based, structured, 1-year, advanced dietary education, per the proposal of a Mediterranean diet vs standard of care, regarding the most relevant CV risk factors (eg, metabolic parameters and body composition) in CD patients.

METHODS AND ANALYSIS

Randomisation will occur after the baseline dietary education and interview in a 1:1 allocation ratio. Outcomes include anthropometric parameters (body composition analysis including weight, Body Mass Index, fat mass, per cent body fat, skeletal muscle mass, visceral fat area and total body water) and CV risk-related metabolic parameters (eg, lipid profile, homocysteine, fasting glucose, haemoglobin A1c, Homeostatic Model Assessment Index, metabolic hormones, waist circumference, blood pressure, liver function tests, liver steatosis rate and diet composition). In this study, we aim to draw attention to a new aspect regarding managing CD: dietary education can lead to a better quality of the GFD, thereby reducing the risk of potential metabolic and CV complications.

ETHICS AND DISSEMINATION

The study was approved by the Scientific and Research Ethics Committee of the Hungarian Medical Research Council (27521-5/2022/EÜIG). Findings will be disseminated at research conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT05530070.

Long-term effects of COVID-19 pandemic on physical activity and eating behaviour of the Italian population: a longitudinal study

BACKGROUND

Restrictive measures due to the Covid-19 pandemic strongly impacted lifestyle and daily behaviour. The purpose of this longitudinal retrospective study was to investigate short-term and long-term effects of Covid-19 pandemic on physical activity and eating habits of the Italian population investigating three time periods: pre-, during- and post-lockdown.

METHODS

A sample of 2773 adults recruited through social media provided data by an online survey administered from July to October 2023. Participants completed the International Physical Activity Questionnaire-Short Form (IPAQ-SF), the Mediterranean Diet Adherence Screener (MEDAS) and provided information about eating habits, socio-demographic and anthropometric characteristics.

RESULTS

There was a significant increase (p < 0.001) in mean BMI from pre-pandemic period (24.53 ± 5.34 Kg/m2) to post-pandemic period (25.22 ± 6.0 Kg/m2). Physical Activity significantly decreased during the pandemic period compared to the pre-pandemic period (χ² = 271.97; p < 0.001; φ = 0.31) with an increase in inactive subjects from 25.7% to 52.8%. In the post pandemic period, there was an increase in the level of Physical Activity compared to the pandemic period (χ² = 413.61; p < 0.001; φ = 0.39) with a reduction of inactive subjects from 52.8% to 25.6%. Adherence to Mediterranean Diet score significantly (p < 0.001) increase from pre-pandemic (7.18 ± 1.58) to during-pandemic (7.29 ± 1.69) and post-pandemic (7.75 ± 1.63) periods with significant differences emerged in the consumption of single MEDAS items during the pandemic period by different BMI classes. Consumption of seasonal fruit and vegetables, water intake, the preparation/consumption of traditional or local dishes and the time dedicated for dinner and lunch significant increase (p < 0.001) during pandemic.

CONCLUSIONS

The Covid-19 pandemic changed people's lifestyles, but in different ways for Physical Activity and diet. During the pandemic there was a negative effect for PA that decreased while the time spent sitting increased. This seems to be a temporary effect as, after the end of the phase of mandatory restrictions, it returns to the original level. The lockdown period improved the quality of the Italian population's eating habits, with an increase in adherence to the Mediterranean diet even after the end of the pandemic showing a rediscovery of traditional dishes, increase in consumption of seasonal products, greater preference for local products and more time spent preparing meals.

Development and Evaluation of the Dietary Pattern Calculator (DiPaC) for Personalized Assessment and Feedback

This study aimed to develop and validate a diet assessment screener - the Dietary Pattern Calculator (DiPaC). A scoping review identified currently available short diet quality assessment tools. Twenty-one articles covering 19 unique tools were included. The current tools mainly focused on individual nutrients or food groups or were developed for a specific population, and few ascertained overall dietary patterns. The 24-hour dietary recalls from the nationally representative Canadian Community Health Survey (CCHS)-Nutrition 2015 (n = 13,958) were used to derive and validate a personalized dietary pattern informed by the scoping review using weighted partial least squares. The dominant dietary pattern in CCHS-Nutrition 2015 was characterized by high consumption of fast foods, carbonated drinks, and salty snacks and low consumption of whole fruits, orange vegetables, other vegetables and juices, whole grains, dark green vegetables, legumes, and soy. The dietary pattern assessment was used to create and evaluate DiPaC following an agile and user-centred research and development approach. DiPaC, which demonstrated high validity and intermediate reliability (internal consistency = 0.47-0.51), is publicly available at https://www.projectbiglife.ca/. DiPaC can be used by the public, clinicians, and researchers for quick and robust assessment of diet quality, providing immediate feedback with the advantage of being easy to implement.

Impact on physical function of the +AGIL Barcelona program in community-dwelling older adults with cognitive impairment: an interventional cohort study

BACKGROUND

Older adults with cognitive impairment (CI) have higher multimorbidity and frailty prevalence, lower functional status and an increased likelihood to develop dementia, non-cognitive deficits, and adverse health-related events. +AGIL, a real-world program for frail older adults in a primary care area of Barcelona, is a pragmatic, multi-component and integrated intervention implemented since 2016. It includes physical activity, nutrition, sleep hygiene, revision and adequacy of pharmacological treatment, detection of undesired loneliness and screening for CI; to improve physical function in community-dwelling older adults. We aimed to assess the + AGIL longitudinal impact on physical function among community-dwelling frail older persons with CI.

METHODS

An interventional cohort study included data from all the + AGIL consecutive participants from July 2016 until March 2020. Based on the comprehensive geriatric assessment, participants were offered a tailored multi-component community intervention, including a 10-week physical activity program led by an expert physical therapist. Physical performance was measured at baseline, three and six months follow-up. The pre-post impact on physical function was assessed by paired sample t-test for repeated samples. Linear mixed models were applied to analyze the + AGIL longitudinal impact. P-values < 0.05 were considered statistically significant.

RESULTS

194 participants were included (82 with CI, based on previous diagnosis or the Mini-COG screening tool), 68% women, mean age 81.6 (SD = 5.8) yo. Participants were mostly independent in Activities of Daily Living (mean Barthel = 92.4, SD = 11.1). The physical activity program showed high adherence (87.6% attended ≥ 75% sessions). At three months, there was a clinically and statistically significant improvement in the Short Physical Performance Battery (SPPB) and its subcomponents in the whole sample and after stratification for CI [CI group improvements: SPPB = 1.1 (SD = 1.8) points, gait speed (GS) = 0.05 (SD = 0.13) m/s, Chair stand test (CST)=-2.6 (SD = 11.4) s. Non-CI group improvements: SPPB = 1.6 (SD = 1.8) points, GS = 0.08 (SD = 0.13) m/s, CST=-6.4 (SD = 12.1) seg]. SPPB and gait speed remained stable at six months in the study sample and subgroups. CI had no significant impact on SPPB or GS improvements.

CONCLUSION

Our results suggest that older adults with CI can benefit from a multidisciplinary integrated and comprehensive geriatric intervention to improve physical function, a component of frailty.

Yearly attained adherence to Mediterranean diet and incidence of diabetes in a large randomized trial

BACKGROUND

Several large observational prospective studies have reported a protection by the traditional Mediterranean diet against type 2 diabetes, but none of them used yearly repeated measures of dietary intake. Repeated measurements of dietary intake are able to improve subject classification and to increase the quality of the assessed relationships in nutritional epidemiology. Beyond observational studies, randomized trials provide stronger causal evidence. In the context of a randomized trial of primary cardiovascular prevention, we assessed type 2 diabetes incidence according to yearly repeated measures of compliance with a nutritional intervention based on the traditional Mediterranean diet.

METHODS

PREDIMED (''PREvención con DIeta MEDiterránea'') was a Spanish trial including 7447 men and women at high cardiovascular risk. We assessed 3541 participants initially free of diabetes and originally randomized to 1 of 3 diets: low-fat diet (n = 1147, control group), Mediterranean diet supplemented with extra virgin olive (n = 1154) or Mediterranean diet supplemented with mixed nuts (n = 1240). As exposure we used actual adherence to Mediterranean diet (cumulative average), yearly assessed with the Mediterranean Diet Adherence Screener (scoring 0 to 14 points), and repeated up to 8 times (baseline and 7 consecutive follow-up years). This score was categorized into four groups: < 8, 8-< 10, 10- < 12, and 12-14 points. The outcome was new-onset type 2 diabetes.

RESULTS

Multivariable-adjusted hazard ratios from time-varying Cox models were 0.80 (95% confidence interval, 0.70-0.92) per + 2 points in Mediterranean Diet Adherence Screener (linear trend p = .001), and 0.46 (0.25-0.83) for the highest (12-14 points) versus the lowest (< 8) adherence. This inverse association was maintained after additionally adjusting for the randomized arm. Age- and sex-adjusted analysis of a validated plasma metabolomic signature of the Mediterranean Diet Adherence Screener (constituted of 67 metabolites) in a subset of 889 participants also supported these results.

CONCLUSIONS

Dietary intervention trials should quantify actual dietary adherence throughout the trial period to enhance the benefits and to assist results interpretation. A rapid dietary assessment tool, yearly repeated as a screener, was able to capture a strong inverse linear relationship between Mediterranean diet and type 2 diabetes. Trial registration ISRCTN35739639.

Dietary biomarkers and food records indicate compliance to study diets in the ADIRA (Anti-inflammatory Diet In Rheumatoid Arthritis) trial

Background

In the ADIRA (Anti-inflammatory Diet In Rheumatoid arthritis) trial, compliance to the study diets has previously been described primarily with a score based on reported intake of trial foods from telephone interviews. The aim of this study was to evaluate compliance using objective dietary biomarkers for whole grain, fruit and vegetables, margarine and oil, seafood and overall fat quality, as well as reported intake from food records of key components of the study diets.

Methods

Fifty patients with rheumatoid arthritis were randomized to begin with the intervention diet (rich in whole grain, fruit and vegetables, margarine/oil and seafood) or the control diet (rich in meat and high-fat dairy) for 10 weeks, followed by a ~ 4 months wash-out period, and then switched diet. Compliance was evaluated using plasma alkylresorcinols (AR) as biomarkers for intake of whole grain wheat and rye, serum carotenoids for fruit and vegetables, plasma linoleic acid (LA, 18:2 n-6) and -α-linolenic acid (18:3, n-3) for margarine and cooking oil, plasma eicosapentaenoic acid (EPA, 20:5 n-3), -docosahexaenoic acid (DHA 22:6, n-3) and -docosapentaenoic acid (22:5 n-3) for seafood, and plasma fatty acid pattern for the overall dietary fat quality. Reported intake of whole grain, fruit, berries and vegetables, seafood, red meat, and fat quality was extracted from 3-d food records.

Results

Plasma AR C21:0 and C23:0, LA, EPA, and DHA were higher while total serum carotenoids were lower after the intervention diet period compared to the control diet period (AR and carotenoids: p = <0.05, fatty acids: p = <0.001). Reported intake of whole grain, fruit, berries and vegetables, and seafood was higher and reported intake of red meat was lower during the intervention diet period compared to the control diet period (p = <0.001). Plasma- and reported fatty acid pattern differed as intended between the diet periods.

Conclusion

This study indicates that the participants in the ADIRA trial were compliant to the study diets regarding intake of whole grain, cooking fat, seafood, and red meat, and the intended overall dietary fat quality. Compliance to instructions on fruit- and vegetable intake remains uncertain.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT02941055?term=NCT02941055&draw=2&rank=1, NCT02941055.

Efficacy of a Short-Term Lifestyle Change Intervention in Healthy Young Men: The FASt Randomized Controlled Trial

The aim of this study was to investigate the impact of dietary habits and physical activity intervention on lifestyle behavior as a prevention tool supported also by personalized motivational counseling. A two-arm randomized controlled trial was carried out. A sample of 18-22-year-old students was randomly assigned to a four-month intervention based on the Mediterranean diet and moderate physical activity program (N = 66) or to a control group (N = 63). The outcomes were adherence to the Mediterranean diet, physical activity level, and nutrients intake, assessed at enrollment (t0), end of intervention (t4, 4 months after the start), and end of follow-up (t8, 8 months after the start). Adherence to the Mediterranean diet increased from t0 to t4 and t8, more in the intervention (6.83, 9.85, and 9.12, respectively) than in the control group (6.73, 7.00, 7.69, respectively) (p < 0.001). Physical activity showed a moderate increase from t0 to t4 and t8 in both groups, without significant differences between them. Significant differences were seen between the two groups in food intake changes, from t0 to t4 and t8. This randomized controlled trial showed that a moderate short-term intervention based on the Mediterranean diet and regular physical activity determined a positive change in the lifestyle of healthy, normal-weight, young men.

The "fruit and whole-grain" pattern is associated with a low prevalence of hypertriglyceridemia among middle and older-aged Korean adults: Using Korea National Health and Nutrition Examination Survey 2013-2018 data

Hypertriglyceridemia is a well-known risk factor of various chronic diseases including diabetes mellitus, metabolic syndrome, obesity, and cardiovascular diseases. This study aimed to determine dietary patterns and explore the relationship between dietary patterns and hypertriglyceridemia in the Korean adult population. We utilized a cross-sectional and nationally representative survey, the Korea National Health and Nutrition Examination Survey 2013-2018 database. From 47,217 subjects who participated in the survey between 2013 and 2018, only subjects over 40 years old were included. Subjects lacking 24-h recall data and data on hypertriglyceridemia and body mass index, and who had implausible energy intake were excluded. A total of 19,806 participants' data were analyzed. Dietary data were based on 24-h recall data, and dietary patterns were derived using factor analysis. Triglyceride levels greater than 200 mg/dl were considered hypertriglyceridemia, according to the Korean Society of Lipid and Atherosclerosis. Three dietary patterns- "oil and fats & seasoning", "soybean paste and vegetable", and "fruit and whole-grain"- explained 7.9%, 6.3%, and 5.8% of variation in food intake, respectively. Comparing the lowest and highest dietary pattern score groups after adjusting for potential confounders revealed an inverse relationship between "fruit and whole-grain" dietary pattern and hypertriglyceridemia in men (odds ratio [OR]: 0.61, 95% confidence interval [CI]: 0.45-0.82, p for trend <.0001); which was only marginal in women (OR: 0.78, 95% CI: 0.58-1.07, p for trend: .628). A diet containing high proportions of fruit and whole-grain may have preventive effects on hypertriglyceridemia in middle and older aged Korean adults.

Validation of the 14-item mediterranean diet adherence screener

BACKGROUND

The Mediterranean diet (MedDiet) is suggested as a healthy dietary pattern. 14-point Mediterranean Diet Adherence Screener (MEDAS) questionnaire is a valid and rapid tool to estimate the adherence to the Mediterranean diet. The aim of this study was to assess the validity of the 14-point Mediterranean Diet Adherence Screener in Turkish population.

METHODS

A total of 188 people (%58 females) participated in this study (31.7 ± 10.97 years). Turkish version of the MEDAS questionnaire was applied with 3-day food record, and mean total Mediterranean Diet (MedDiet) score and each of the MedDiet component scores was calculated from both 3-day food records and MEDAS tool. Intra-class correlation coefficient (ICC) was used to evaluate the total score agreement between the two dietary assessment methods, and each of the MedDiet components was estimated using Cohen's kappa. This project was a cross-sectional study.

RESULTS

There was good correlation between the food record total MEdDiet score and MEDAS-derived MedDiet score (r = 0.750, p < 0.001; ICC = 0.749, 95% CI 0.679-0.806, p < 0.001). Highest concordance was observed for olive oil for cooking (К = 0.763), sugar sweetened beverages (К = 0.666), sweets, pastries (К = 0.753), and sofrito (К = 0.796) while the lowest was for fish and seafood (К = 0.196). Re-test analysis showed a similar mean total MedDiet score for both administrations of MEDAS.

CONCLUSIONS

The MEDAS is a valid and reliable tool to assess adherence to the Mediterranean diet in Turkish population.

Changes in fatty acid levels after consumption of a novel docosahexaenoic supplement from algae: a crossover randomized controlled trial in omnivorous, lacto-ovo vegetarians and vegans

Purpose

To determine serum fatty acids of lacto-ovo vegetarian (LOV), vegan (VEG) and omnivorous (OMN) adults, and to analyse the effects of consuming a docosahexaenoic acid (DHA) supplement of vegetable origin on fatty acid profile.

Methods

A randomized, double-blind, placebo-controlled crossover design was conducted in healthy adults. Volunteers (n = 116) were randomly assigned to a DHA-supplement (dose 250 mg/day), made from the microalgae Schizochytrium sp., or a placebo during 5-week periods separated by a 5-week washout interim period. Compliance and dietary intake were estimated and serum fatty acids were determined by gas chromatography. Results were analysed by mixed linear models.

Results

Percentage of linoleic acid (C18:2n6) in serum was the highest among the fatty acids in the three diet groups, followed by oleic (C18:1n9) and palmitic (C16:0) acids. Linoleic (C18:2n6) and alpha-linolenic (C18:3n3) acids were higher in VEG compared to OMN (p < 0.001), while in LOV, their levels were intermediate between the other groups. Women presented higher DHA (C22:6n3) than men (p < 0.001). The DHA-supplement increased serum DHA compared to placebo in the three diet groups (p < 0.001), and a higher increase was observed in VEG followed by LOV (p < 0.001). The ratio serum n-6/n-3 improved by the supplementation but remained higher in LOV and VEG than in OMN. In contrast, the DHA-supplement decreased docosapentaenoic (C22:5n3) and docosatetraenoic (C22:4n6) acids in all diet groups (p < 0.001) and increased the eicosapentaenoic to alpha-linolenic fatty acids ratio (p = 0.016).

Conclusion

The DHA-supplement at dose of 250 mg/day was effective in increasing serum DHA either in omnivorous, lacto-ovo vegetarian and vegan adults.

Clinical trial registration

Registered at Clinicaltrials.gov (www.clinicaltrials.gov), NCT04278482.

Effectiveness of a multiple health-behaviour-change intervention in increasing adherence to the Mediterranean Diet in adults (EIRA study): a randomized controlled hybrid trial

BACKGROUND

The present study describes the effectiveness of a complex intervention that addresses multiple lifestyles to promote healthy behaviours in increasing adherence to the Mediterranean diet (MD).  METHODS: Cluster-randomised, hybrid clinical trial controlled with two parallel groups. The study was carried out in 26 primary Spanish healthcare centres. People aged 45-75 years who presented at least two of the following criteria were included: smoker, low adherence to the MD or insufficient level of physical activity. The intervention group (IG) had three different levels of action: individual, group, and community, with the aim of acting on the behaviours related to smoking, diet and physical activity at the same time. The individual intervention included personalised recommendations and agreements on the objectives to attain. Group sessions were adapted to the context of each healthcare centre. The community intervention was focused on the social prescription of resources and activities performed in the environment of the community of each healthcare centre. Control group (CG) received brief advice given in the usual visits to the doctor's office. The primary outcome was the change, after 12 months, in the number of participants in each group with good adherence to the MD pattern. Secondary outcomes included the change in the total score of the MD adherence score (MEDAS) and the change in some cardiovascular risk factors.

RESULTS

Three thousand sixty-two participants were included (IG = 1,481, CG = 1,581). Low adherence to the MD was present in 1,384 (93.5%) participants, of whom 1,233 initiated the intervention and conducted at least one individual visit with a healthcare professional. A greater increase (13.7%; 95% CI, 9.9-17.5; p < 0.001) was obtained by IG in the number of participants who reached 9 points or more (good adherence) in the MEDAS at the final visit. Moreover, the effect attributable to the intervention obtained a greater increase (0.50 points; 95% CI, 0.35 to 0.66; p < 0.001) in IG.

CONCLUSIONS

A complex intervention modelled and carried out by primary healthcare professionals, within a real clinical healthcare context, achieved a global increase in the adherence to the MD compared to the brief advice.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03136211. Retrospectively registered on 02/05/2017 https://clinicaltrials.gov/ct2/show/NCT03136211.

FTO and Anthropometrics: The Role of Modifiable Factors

Numerous gene variants are linked to an individual's propensity to become overweight or obese. The most commonly studied gene variant is the FTO single nucleotide polymorphism. The FTO risk allele is linked with increased body mass, BMI and other lifestyle factors that may perpetuate an individual's risk for obesity. Studies assessing eating behaviors, eating preferences, nutrition interventions and other lifestyle factors were reviewed. These studies demonstrated a clear difference in eating behaviors and preferences. Lifestyle modifications including physical activity and diet were effective in weight management even in those with the risk allele.

Long-term effect of a dietary intervention with two-healthy dietary approaches on food intake and nutrient density in coronary patients: results from the CORDIOPREV trial

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of disease burden in the world by non-communicable diseases. Nutritional interventions promoting high-quality dietary patterns with low caloric intake value and high nutrient density (ND) could be linked to a better control of CVD risk and recurrence of coronary disease. This study aims to assess the effects of a dietary intervention based on MedDiet or Low-Fat dietary intervention over changes in ND and food intake after 1 and 7 years of follow-up of the CORDIOPREV study.

METHODS

We prospectively analyzed the results of the 802 coronary patients randomized to two healthy dietary patterns (MedDiet = 425, Low-Fat Diet = 377) who completed the 7 years of follow-up and had all the dietary data need. Dietary intake information obtained from a validated 137-item Food Frequency Questionnaire was used to calculate 1- and 7-year changes in dietary intake and ND (measured as nutrient intake per 1000 kcal). T test was used to ascertain differences in food intake and ND between groups across follow-up time. Within-subject (dietary allocation group) differences were analyzed with ANOVA repeated measures.

RESULTS

From baseline to 7 years of follow-up, significant increases of vegetables, fruits, and whole cereals within groups (p < 0.001) was found. We found a higher increase in dietary intake of certain food groups with MedDiet in comparison with Low-Fat Diet for vegetables (46.1 g/day vs. 18.1 g/day, p < 00.1), fruits (121.3 g/day vs. 72.9 g/day), legumes (4.3 g/day vs. 0.16 g/day) and nuts (7.3 g/day vs. - 3.7 g/day). There was a decrease in energy intake over time in both groups, slightly higher in Low-Fat Diet compared to MedDiet group (- 427.6 kcal/day vs. - 279.8 kcal/day at 1st year, and - 544.6 kcal/day vs. - 215.3 kcal/day after 7 years of follow-up). ND of all the nutrients increased within group across follow-up time, except for Saturated Fatty Acids (SFA), cholesterol and sodium (p < 0.001).

CONCLUSIONS

A comprehensive dietary intervention improved quality of diet, reducing total energy intake and increasing the intake of healthy food groups and overall ND after 1 year and maintaining this trend after 7 years of follow-up. Our results reinforce the idea of the participation in trials, enhance nutrition literacy and produces better nutritional outcomes in adult patients with established CVD.

CLINICAL TRIAL REGISTRY

The trial was registered in 2009 at ClinicalTrials.gov (number NCT00924937).

A Mediterranean and Low-Fat dietary intervention in Non-Alcoholic Fatty Liver Disease patients -Exploring participant experience and perceptions about dietary change

BACKGROUND

A Mediterranean Diet (MD) appears to be beneficial in NAFLD patients in Mediterranean countries, however the acceptability of a MD in non-Mediterranean populations has not been thoroughly explored. This study aimed to explore the acceptability, through understanding the barriers and enablers of MD and low-fat diet (LFD) interventions as perceived by Australian adults from multicultural backgrounds, with NAFLD, who participated.

METHODOLOGY

Semi-structured telephone interviews were performed with 23 NAFLD trial participants at the end of a 12-week dietary intervention in a multicentre, parallel, randomised clinical trial. Data was analysed using thematic analysis.

RESULTS

Participants reported that they enjoyed taking part in the MD and LFD interventions and perceived that they had positive health benefits from their participation. Compared to the LFD, the MD group placed greater emphasis on enjoyment and intention to maintain dietary changes. Novelty, convenience and the ability to swap food/meals were key enablers for the successful implementation for both of the dietary interventions. Flavour and enjoyment of food, expressed more prominently by MD intervention participants, were fundamental components of the diets with regard to reported adherence and intention to maintain dietary change.

CONCLUSIONS

Participants randomised to the MD reported greater acceptability of the diet than those randomised to the LFD, predominantly related to perceived novelty and palatability of the diet. This article is protected by copyright. All rights reserved.

Scope of Use and Effectiveness of Dietary Interventions for Improving Health-Related Outcomes in Veterans: A Systematic Review

Military veterans often have numerous physical and mental health conditions and can face unique challenges to intervention and management. Dietary interventions can improve the outcomes in many health conditions. This study aimed to evaluate the scope of health conditions targeted with dietary interventions and the effectiveness of these interventions for improving health-related outcomes in veterans. A systematic literature review was performed following PRISMA guidelines to identify and evaluate studies related to veterans and dietary interventions. Five electronic databases were searched, identifying 2669 references. Following screening, 35 studies were evaluated, and 18 were related to a US national veteran weight-loss program. The included studies were critically appraised, and the findings were narratively synthesized. Study designs ranged from randomised controlled trials to cohort studies and were predominantly U.S. based. The intervention durations ranged from one to 24 months. The mean subject age ranged from 39.0 to 69.7 years, with often predominantly male participants, and the mean body mass index ranged from 26.4 to 42.9 kg/m². Most dietary interventions for veterans were implemented in populations with overweight/obesity or chronic disease and involved single dietary interventions or dietary components of holistic lifestyle interventions. The most common primary outcome of interest was weight loss. The success of dietary interventions was generally moderate, and barriers included poor compliance, mental health conditions and large drop-out rates. The findings from this review illustrate the need for further refinement of dietary and lifestyle interventions for the management of veterans with chronic health conditions.

Long-term secondary prevention of cardiovascular disease with a Mediterranean diet and a low-fat diet (CORDIOPREV): a randomised controlled trial

BACKGROUND

Mediterranean and low-fat diets are effective in the primary prevention of cardiovascular disease. We did a long-term randomised trial to compare the effects of these two diets in secondary prevention of cardiovascular disease.

METHODS

The CORDIOPREV study was a single-centre, randomised clinical trial done at the Reina Sofia University Hospital in Córdoba, Spain. Patients with established coronary heart disease (aged 20-75 years) were randomly assigned in a 1:1 ratio by the Andalusian School of Public Health to receive a Mediterranean diet or a low-fat diet intervention, with a follow-up of 7 years. Clinical investigators (physicians, investigators, and clinical endpoint committee members) were masked to treatment assignment; participants were not. A team of dietitians did the dietary interventions. The primary outcome (assessed by intention to treat) was a composite of major cardiovascular events, including myocardial infarction, revascularisation, ischaemic stroke, peripheral artery disease, and cardiovascular death. This study is registered with ClinicalTrials.gov, NCT00924937.

FINDINGS

From Oct 1, 2009, to Feb 28, 2012, a total of 1002 patients were enrolled, 500 (49·9%) in the low-fat diet group and 502 (50·1%) in the Mediterranean diet group. The mean age was 59·5 years (SD 8·7) and 827 (82·5%) of 1002 patients were men. The primary endpoint occurred in 198 participants: 87 in the Mediterranean diet group and 111 in the low-fat group (crude rate per 1000 person-years: 28·1 [95% CI 27·9-28·3] in the Mediterranean diet group vs 37·7 [37·5-37·9] in the low-fat group, log-rank p=0·039). Multivariable-adjusted hazard ratios (HRs) of the different models ranged from 0·719 (95% CI 0·541-0·957) to 0·753 (0·568-0·998) in favour of the Mediterranean diet. These effects were more evident in men, with primary endpoints occurring in 67 (16·2%) of 414 men in the Mediterranean diet group versus 94 (22·8%) of 413 men in the low-fat diet group (multiadjusted HR 0·669 [95% CI 0·489-0·915], log-rank p=0·013), than in 175 women for whom no difference was found between groups.

INTERPRETATION

In secondary prevention, the Mediterranean diet was superior to the low-fat diet in preventing major cardiovascular events. Our results are relevant to clinical practice, supporting the use of the Mediterranean diet in secondary prevention.

FUNDING

Fundacion Patrimonio Comunal Olivarero; Fundacion Centro para la Excelencia en Investigacion sobre Aceite de Oliva y Salud; local, regional, and national Spanish Governments; European Union.

Short-Term Pilot Study to Evaluate the Impact of Salbi Educa Nutrition App in Macronutrients Intake and Adherence to the Mediterranean Diet: Randomized Controlled Trial

Promoting a healthy diet is a relevant strategy for preventing non-communicable diseases. This study aims to evaluate the impact of an innovative tool, the SAlBi educa nutrition app, in primary healthcare dietary counseling to improve dietary profiles as well as adherence to the Mediterranean diet. A multi-center randomized control trial comprising 104 participants was performed. Both control (n = 49) and intervention (n = 55) groups attended four once-weekly sessions focusing on healthy eating habits and physical activity, over one month. As well as attending the meetings, the intervention group used the app, which provides self-monitoring and tailored dietary advice based on the Mediterranean diet model. In a second intervention (one arm trial), the potential of SAlBi educa was evaluated for three months during the COVID-19 pandemic. At 4 weeks, the intervention group had significantly increased their carbohydrate intake (7.7% (95% CI: 0.16 to 15.2)) and decreased their total fat intake (−5.7% (95% CI: −10.4 to −1.15)) compared to the control group. Significant differences were also found for carbohydrates (3.5% (95% CI: −1.0 to 5.8)), total fats (−5.9% (95% CI: −8.9 to −3.0)), fruits and vegetables (266.3 g/day (95% CI: 130.0 to 402.6)), legumes (7.7g/day (95% CI: 0.2 to 15.1)), starchy foods (36.4 g/day (95% CI: 1.1 to 71.7)), red meat (−17.5 g/day (95% CI: −34.0 to −1.1)), and processed meat (−6.6 g/day (95% CI: −13.1 to −0.1)) intakes during the COVID-19 pandemic. SAlBi educa is a useful tool to support nutrition counseling in primary healthcare, including in special situations such as the COVID-19 pandemic. Trial registration: ISRCTN57186362.

Effectiveness of an Intervention Programme on Adherence to the Mediterranean Diet in a Preschool Child: A Randomised Controlled Trial

Background: The Mediterranean diet is considered one of the dietary patterns with the most accumulated scientific evidence on health benefits. In children, it has positive effects in the prevention of obesity and cardiovascular diseases, as well as in the prevention of diabetes. We aimed to evaluate the medium-term efficacy of an intervention programme, targeting adherence to the Mediterranean diet among preschool children. Methods: In a randomised, parallel trial of participants aged 3–5 years, a school garden was attended in the experimental group, and in the control group, the usual content on the human body and health were taught. Adherence to the Mediterranean diet was assessed using the KIDMED questionnaire, controlling for weight, height, body mass index (BMI) and socio-demographic variables. Results: A reduction in BMI was found in the experimental group after one year and at the end of the follow-up period. In the overall score obtained in the KIDMED survey, a statistical trend was found between the two groups (p = 0.076). In multivariate analysis, consumption of pulses more than once a week’ was predictive of improved diet quality, with an Odds Ratio (OR) in the experimental group of 1.382 (95% CI 1.126–1.695; p = 0.009). Conclusions: The experimental approach improved the quality of the participants’ diet, increasing adherence to the Mediterranean diet due to increased consumption of plant-based protein.

Feasibility and preliminary efficacy of the LEAD trial: a cluster randomized controlled lifestyle intervention to improve hippocampal volume in older adults at-risk for dementia

BACKGROUND

Healthy diet and exercise are associated with reduced risk of dementia in older adults. The impact of diet and exercise interventions on brain health is less consistent, especially with dietary interventions which rely on varying approaches. Our objective was to evaluate the feasibility and preliminary efficacy of a 6-month intervention combining exercise with a novel dietary counseling approach to improve hippocampal volume among older adults at-risk for dementia.

METHODS

Participants with vascular risk factors and subjective cognitive decline or early mild cognitive impairment were cluster randomized in groups of 3-4 to the diet intervention (DIET) or control education (ED) group. All participants engaged in 1 h of supervised exercise per week and additional exercise at home. DIET involved 1 h per week of group-based dietary counseling comprising education, goal setting, and strategy training. ED involved 1 h per week of group-based brain health education classes. Our primary outcome was change in hippocampal volume from baseline to 6 months. Secondary outcomes included changes in cognitive function, blood biomarkers, diet, and fitness. Recruitment challenges and early discontinuation of the trial due to COVID-19 necessitated a revised focus on feasibility and preliminary efficacy.

RESULTS

Of 190 older adults contacted, 14 (7%) were eligible and enrolled, constituting 21% of our recruitment target. All participants completed the intervention and attended 90% of exercise and DIET/ED sessions on average. All 6-month assessments prior to COVID-19 were completed but disruptions to in-person testing resulted in incomplete data collection. No serious adverse events occurred and all participants expressed positive feedback about the study. Preliminary findings did not identify any significant changes in hippocampal volume; however, substantial improvements in diet and HbA1c were observed with DIET compared to ED (d = 1.75 and 1.07, respectively).

CONCLUSIONS

High adherence and retention rates were observed among participants and preliminary findings illustrate improvements in diet quality and HbA1c. These results indicate that a larger trial is feasible if difficulties surrounding recruitment can be mitigated.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03056508 .

Beyond the clinical walls: registered dietitian nutritionists providing medical nutrition therapy in the home setting

BACKGROUD/OBJECTIVES

Registered dietitian nutritionists (RDN) are providers of medical nutrition therapy (MNT) to address health and chronic disease. Traditionally, RDNs have provided care in healthcare facilities including hospitals and private care facilities. The purpose of this study was to determine how RDN individualized MNT in the home impacted nutrition, physical activity, and food security.

SUBJECTS/METHODS

This is a secondary data analysis. The mean age of the participants (n = 1,007) was 51.6 years old with a mean body mass index (BMI) of 34.1 kg/m². Individualized MNT visits were delivered by an RDN in the home setting from January to December 2019. Participants were referred by healthcare professionals or self-referred. Participants had MNT benefits covered by their health insurance plan (43.3% Medicaid; 39.8% private insurance; 7.9% Medicare, 9% other). Health outcomes related to nutrition care were measured. Outcomes included self-reported consumption of nutrition factors and physical activity. Our secondary outcome focused on food security. The changes in weight, BMI, physical activity, and nutrition factors were analyzed by a linear regression model or linear mixed model, adjusting for age, sex, baseline value, and number of appointments. Food security was summarized in a 2 by 2 contingency table.

RESULTS

Baseline values had significantly negative impacts for all changes and number of appointments was significant in the changes for weight and BMI. Increases in physical activity were significant for both female and male participants, 10.4 and 12.6 minutes per day, respectively, while the changes in weight and BMI were not. Regarding dietary factors, the consumption total servings per day of vegetables (0.13) and water (3.35) significantly increased, while the consumption of total servings of whole grain (−0.27), fruit (−0.32), dairy (−0.80) and fish (−0.81) significantly decreased. About 24% (of overall population) and 45% (of Medicaid population) reported improvements in food security.

CONCLUSIONS

This study found that home visits were a useful setting for MNT delivered by RDNs. There is a strong need for individualized counseling to meet the participants' needs and personal goals.

The impact of Mediterranean diet on coronary plaque vulnerability, microvascular function, inflammation and microbiome after an acute coronary syndrome: study protocol for the MEDIMACS randomized, controlled, mechanistic clinical trial

Background

Primary prevention trials have demonstrated that the traditional Mediterranean diet is associated with a reduction in cardiovascular mortality and morbidity. However, this benefit has not been proven for secondary prevention after an acute coronary syndrome (ACS). We hypothesized that a high-intensity Mediterranean diet intervention after an ACS decreases the vulnerability of atherosclerotic plaques by complex interactions between anti-inflammatory effects, microbiota changes and modulation of gene expression.

Methods

The MEDIMACS project is an academically funded, prospective, randomized, controlled and mechanistic clinical trial designed to address the effects of an active randomized intervention with the Mediterranean diet on atherosclerotic plaque vulnerability, coronary endothelial dysfunction and other mechanistic endpoints. One hundred patients with ACS are randomized 1:1 to a monitored high-intensity Mediterranean diet intervention or to a standard-of-care arm. Adherence to diet is assessed in both arms using food frequency questionnaires and biomarkers of compliance. The primary endpoint is the change (from baseline to 12 months) in the thickness of the fibrous cap of a non-significant atherosclerotic plaque in a non-culprit vessel, as assessed by repeated optical coherence tomography intracoronary imaging. Indices of coronary vascular physiology and changes in gastrointestinal microbiota, immunological status and protein and metabolite profiles will be evaluated as secondary endpoints.

Discussion

The results of this trial will address the key effects of dietary habits on atherosclerotic risk and will provide initial data on the complex interplay of immunological, microbiome-, proteome- and metabolome-related mechanisms by which non-pharmacological factors may impact the progression of coronary atherosclerosis after an ACS.

Trial registration

ClinicalTrials.govNCT03842319. Registered on 13 May 2019

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05746-z.

The impact a Mediterranean Diet in the third trimester of pregnancy has on neonatal body fat percentage

Maternal diet during pregnancy has long been recognised as an important determinant of neonatal outcomes and child development. Infant body composition is a potentially modifiable risk factor for predicting future health and metabolic disease. Utilising the Mediterranean Diet Score, this study focused on how different levels of Mediterranean Diet adherence (MDA) in pregnancy influence body fat percentage of the infant. Information on 458 pregnant women in their third trimester of pregnancy and their infants was obtained from The ORIGINS Project. The data included MDA score, body composition measurements using infant air displacement plethysmography (PEA POD), pregnancy, and birth information. Infants born to mothers with high MDA had a body fat percentage of 11.3%, whereas infants born to mothers with low MDA had a higher body fat percentage of 13.3% (p = 0.010). When adjusted for pre-pregnancy body mass index and infant sex, a significant result remained between high vs. low MDA and infant fat mass (FM) (2.5% less FM p = 0.016). This study suggests that high MDA in pregnancy was associated with a reduced body fat percentage in the newborn. Future studies are needed to understand whether small but significant changes in FM persist throughout childhood.

Nutritional counseling frequency and baseline food pattern predict implementation of a high-protein and high-polyunsaturated fatty acid dietary pattern: 1-year results of the randomized NutriAct trial

BACKGROUND & AIMS

NutriAct is a 36-month randomized controlled multi-center trial designed to analyze the effects of a food pattern focusing on a high-protein and high-unsaturated fatty acids (UFA) intake on healthy aging. We aimed to determine factors associated with a successful modulation of dietary pattern after 12 months in elderly participants.

METHODS

502 participants were randomized into either usual care control group including dietary recommendations of the German Nutrition Society (DGE) or an intervention group, which used supplementation of rapeseed oil and specifically designed foods as well as repetitive advices to implement a food pattern based on high intake of predominantly plant proteins, UFA and fiber (NutriAct pattern). Food intake was repeatedly assessed by 3-day food records at months 0, 3, 6 and 12. Linear regression models were used to investigate determinants of basal food intake and modulation of dietary pattern during the intervention.

RESULTS

Food records of 242 intervention and 246 control participants (median age 66 y, 37% males) were available at baseline and were included. At baseline, high BMI was related to higher protein and saturated fatty acids and lower fiber intake. The intervention resulted in higher intake of protein, mono- and polyunsaturated fatty acids (MUFA and PUFA) and fiber, and lower carbohydrate and saturated fatty acid consumption (all p < 0.001). While individuals who were already at baseline closer to the NutriAct pattern also achieved a diet closer to the proposed pattern at month 12, the strongest absolute changes (%E) of dietary behavior were seen in those with dietary patterns further away from the proposed pattern at baseline. Attendance to nutritional sessions was crucial to change MUFA, PUFA, fiber and carbohydrate intake.

CONCLUSIONS

A successful modification of dietary pattern was achieved by the performed intervention within 12 months. Baseline dietary habits and attendance to nutritional sessions were substantial determinants predicting changes in dietary pattern.

CLINICAL TRIAL REGISTRATION

The trial was registered at German Clinical Trials Register (drks.de) as DRKS00010049.

Towards reduced meat consumption: A systematic literature review of intervention effectiveness, 2001-2019

A reduction of meat consumption and shift to plant-based diets, especially in industrialized countries, is acknowledged as crucial for reaching climate targets, addressing public health problems, and protecting animal welfare. While scholarly research distilled drivers of meat consumption and barriers to its reduction, insights into the effectiveness of measures to initiate such a profound change in consumer behaviour are relatively scarce. This paper presents a systematic literature review on consumption-side interventions in the context of meat consumption across scholarly disciplines. Our analysis confirms that existing research predominantly assessed interventions addressing personal factors of behavioural change such as knowledge and emotions. Whether these interventions are effective depends on whether information (i) is provided on health, animal welfare or environmental effects, (ii) is emotionally or cognitively framed, and (iii) is aligned with consumers' information needs. Moreover, linking meat to living animals or to the humanness of animals activates negative emotions and, thus, reduces meat consumption. Further, increasing the visibility and variety of vegetarian dishes in food environments decreases meat-eating. Also, educational courses on how to shop and cook vegetarian food are effective in reducing meat consumption. There is less evidence on the effectiveness of interventions addressing socio-cultural factors such as social norms. Regarding future research directions, existing research mainly investigated the influence of interventions on attitudes and behavioural intentions. Hence, there is still a need for studies to assess more long-term effects of intervention measures on actual meat consumption and their potential to initiate fundamental changes in dietary habits.

Behavior change factors and retention in dietary interventions for older adults: scoping review

BACKGROUND AND OBJECTIVES

Although poor diet is a major driver of morbidity and mortality in people 60 and older, few dietary interventions are widely implemented for this population. We mapped behavior change theories, agents, and techniques in dietary interventions for adults 60+ and explored relationships between these factors and ability to retain at least 80% of the study participants.

RESEARCH DESIGN AND METHODS

We conducted a scoping review using MEDLINE, CINAHL, and Web of Science through April 2021 for dietary interventions in adults 60 and older. We collated, summarized, and calculated frequency distributions of behavior change theories, behavior change agents, and behavior change techniques (BCTs) using BCTv1 taxonomy with regard to participant retention across 43 studies.

RESULTS

Only 49% and 30% of the studies reported behavior theory and change agents respectively. Of the studies reporting on theory and agents, the most common were social cognitive theory and the related mechanism of self-efficacy. The most common BCTv1 were "shaping knowledge" and "goals and planning." Several BCTv1 such as "antecedents" and "reward and threat" and evidence for concordance between BCTs and change agents were more common in interventions with higher retention rates.

DISCUSSION AND IMPLICATIONS

Mechanistically concordant studies with BCTs that involve resource allocation and positive reinforcement through rewards may be advantageous for retention in dietary intervention for older adults. Future studies should continue developing theory and mechanism-oriented research. Furthermore, future studies should consider diversifying the portfolio of currently deployed BCTs and strengthening a concordance between BCTs and mechanisms of change.

An Italian Survey on Dietary Habits and Changes during the COVID-19 Lockdown

The World Health Organization has declared the coronavirus outbreak a Public Health Emergency of International Concern; the outbreak has led to lockdowns in several parts of the world, and sudden changes in people's lifestyles. This study explores the impact of the first coronavirus disease 2019 (COVID-19) pandemic period on dietary habits, lifestyle changes, and adherence to the Mediterranean diet among the Italian population, through an online questionnaire, conducted from April to May 2020, involving 1519 participants. The 14-point Mediterranean Diet Adherence Screener (MEDAS) highlighted a medium Mediterranean diet adherence in 73.5% of responders, which principally included the younger population, aged 18-30 years (p < 0.05). In regards to changes in eating habits, 33.5% of responders declared an influence of the pandemic period on nutritional practice. A decrease in alcohol consumption was reported by 81% of responders, while an increase in frozen food consumption was reported by 81.3% of responders. In addition, 58.8% reported positive weight modification (40.8%, +1-3 kg); physical activity reduction was reported for 70.5% of responders. Our study contributes toward amplifying the investigation on the dietary habits and changes of the Italian population during the COVID-19 lockdown, although the pandemic is ongoing. Similar studies should be performed around the world to understand how the emergency has impacted people's habits.

Deep dive to the secrets of the PREDIMED trial

PURPOSE OF REVIEW

The aim of this study was to briefly summarize the contribution of the PREDIMED (PREvención con DIeta MEDiterránea) trial on cardiovascular evidence and examine in depth its groundbreaking trajectory.PREDIMED was conducted during 2003-2010 and represented the largest primary prevention trial ever testing the effects of changes in a complete food pattern (namely, the Mediterranean diet) on cardiovascular disease (CVD). Major contributions relied on the relevant changes in the food pattern attained by the behavioural intervention and their robust effect in reducing hard clinical end-points. Given some potential concerns, which were appropriately addressed with supporting analyses, this review is timely and relevant.

RECENT FINDINGS

PREDIMED has continued contributing to the existing literature with extensive, robust and abundant new evidence on the benefits of the Mediterranean diet, particularly on cardiovascular health, including recent studies using high-throughput metabolomic techniques. After robustly addressing some controversies, the conclusions of the original trial remained unaltered.

SUMMARY

The Mediterranean diet represents an effective and robust nutritional strategy against CVD in high cardiovascular risk populations. Recent findings from the PREDIMED have identified a metabolic signature of the Mediterranean diet that can objectively determine dietary adherence and predict CVD risk. This metabolomic signature opens up a new era for nutritional epidemiology and personalized nutrition.

Behavioral and Physical Activity Interventions for HAND

Approximately 30-50% of persons living with HIV manifest some degree of neurocognitive impairment. Even mild-to-moderate forms of HIV-associated neurocognitive disorders (HAND) can result in difficulties with everyday functioning, such as suboptimal medication adherence and impaired driving. Despite the pervasive presence and consequences of HAND, there is a significant unmet need to develop effective behavioral strategies to reduce the incidence and consequences of HAND. Although there is an absence of evidence-based behavioral interventions specific to HAND, the literature reviewed in this chapter suggest the following modifiable lifestyle factors as intervention targets: physical activity, diet, sleep, and antiretroviral medication adherence. Adoption and maintenance of these healthy lifestyle factors may reduce inflammation and oxidative stress, which, in turn, may reduce the incidence and/or severity of HAND.

A Remote Nutritional Intervention to Change the Dietary Habits of Patients Undergoing Ablation of Atrial Fibrillation: Randomized Controlled Trial

BACKGROUND

The Prevention With Mediterranean Diet (PREDIMED) trial supported the effectiveness of a nutritional intervention conducted by a dietitian to prevent cardiovascular disease. However, the effect of a remote intervention to follow the Mediterranean diet has been less explored.

OBJECTIVE

This study aims to assess the effectiveness of a remotely provided Mediterranean diet-based nutritional intervention in obtaining favorable dietary changes in the context of a secondary prevention trial of atrial fibrillation (AF).

METHODS

The PREvention of recurrent arrhythmias with Mediterranean diet (PREDIMAR) study is a 2-year multicenter, randomized, controlled, single-blinded trial to assess the effect of the Mediterranean diet enriched with extra virgin olive oil (EVOO) on the prevention of atrial tachyarrhythmia recurrence after catheter ablation. Participants in sinus rhythm after ablation were randomly assigned to an intervention group (Mediterranean diet enriched with EVOO) or a control group (usual clinical care). The remote nutritional intervention included phone contacts (1 per 3 months) and web-based interventions with provision of dietary recommendations, and participants had access to a web page, a mobile app, and printed resources. The information is divided into 6 areas: Recommended foods, Menus, News and Online resources, Practical tips, Mediterranean diet classroom, and Your personal experience. At baseline and at 1-year and 2-year follow-up, the 14-item Mediterranean Diet Adherence Screener (MEDAS) questionnaire and a semiquantitative food frequency questionnaire were collected by a dietitian by phone.

RESULTS

A total of 720 subjects were randomized (365 to the intervention group, 355 to the control group). Up to September 2020, 560 subjects completed the first year (560/574, retention rate 95.6%) and 304 completed the second year (304/322, retention rate 94.4%) of the intervention. After 24 months of follow-up, increased adherence to the Mediterranean diet was observed in both groups, but the improvement was significantly higher in the intervention group than in the control group (net between-group difference: 1.8 points in the MEDAS questionnaire (95% CI 1.4-2.2; P<.001). Compared with the control group, the Mediterranean diet intervention group showed a significant increase in the consumption of fruits (P<.001), olive oil (P<.001), whole grain cereals (P=.002), pulses (P<.001), nuts (P<.001), white fish (P<.001), fatty fish (P<.001), and white meat (P=.007), and a significant reduction in refined cereals (P<.001), red and processed meat (P<.001), and sweets (P<.001) at 2 years of intervention. In terms of nutrients, the intervention group significantly increased their intake of omega-3 (P<.001) and fiber (P<.001), and they decreased their intake of carbohydrates (P=.02) and saturated fatty acids (P<.001) compared with the control group.

CONCLUSIONS

The remote nutritional intervention using a website and phone calls seems to be effective in increasing adherence to the Mediterranean diet pattern among AF patients treated with catheter ablation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03053843; https://www.clinicaltrials.gov/ct2/show/NCT03053843.

Increasing dietary fibre intake in healthy adults using personalised dietary advice compared with general advice: a single-blind randomised controlled trial

Objective:

A high-fibre diet is associated with a lower risk for diseases. However, few adults meet the dietary fibre recommendation. Therefore, the effects and acceptance of an algorithm-generated personalised dietary advice (PDA) compared with general advice (GA) on fibre intake were investigated.

Design:

A 6-week, single-blind randomised controlled trial with a 3-month follow-up.

Setting:

PDA was based on habitual intake and provided fibre-rich alternatives using a website; GA contained brochures. Dietary intake was assessed at baseline, week 1, week 6 and 3-month follow-up. Both groups evaluated their advice at week 6. All participants had access to PDA from week 7 until 3-month follow-up.

Participants:

Two groups of healthy adults: PDA (n 34) and GA (n 47). For 3-month follow-up analysis, participants were re-divided into visitors (n 52) and non-visitors (n 26) of the PDA.

Results:

At week 6, energy intake remained stable in both groups, but fibre intake per 1000 kcal increased non-significantly in both groups (PDA = Δ0·5 ± 2·8; GA = Δ0·8 ± 3·1, P = 0·128). Importantly, a significantly higher percentage of PDA participants adhered to the recommendation compared with week 1 (PDA = 21 % increase; GA = 4 % increase, P ≤ 0·001). PDA participants evaluated the advice significantly better compared with GA participants. At 3-month follow-up, fibre intake increased compared with baseline (visitors = Δ2·2 ± 2·6, P < 0·001; non-visitors = Δ1·5 ± 1·9, P = 0·001), but was insignificantly different between groups. Visitors had a decrease and non-visitors had an increase in energy intake (visitors =Δ − 132 ± 525; non-visitors = Δ109 ± 507, P = 0·055).

Conclusions:

The algorithm-generated PDA was well accepted and stimulated adherence to the recommendations more than GA, indicating to be a suitable and cost-efficient method for improving dietary fibre intake in healthy adults.

Reduction in saturated fat intake for cardiovascular disease

BACKGROUND

Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from saturated fats eliminated from the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein.

OBJECTIVES

To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA), monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials.

SEARCH METHODS

We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) on 15 October 2019, and searched Clinicaltrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) on 17 October 2019.

SELECTION CRITERIA

Included trials fulfilled the following criteria: 1) randomised; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) compared with higher saturated fat intake or usual diet; 4) not multifactorial; 5) in adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 6) intervention duration at least 24 months; 7) mortality or cardiovascular morbidity data available.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed inclusion, extracted study data and assessed risk of bias. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses, funnel plots and GRADE assessment.

MAIN RESULTS

We included 15 randomised controlled trials (RCTs) (16 comparisons, 56,675 participants), that used a variety of interventions from providing all food to advice on reducing saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 17% (risk ratio (RR) 0.83; 95% confidence interval (CI) 0.70 to 0.98, 12 trials, 53,758 participants of whom 8% had a cardiovascular event, I² = 67%, GRADE moderate-quality evidence). Meta-regression suggested that greater reductions in saturated fat (reflected in greater reductions in serum cholesterol) resulted in greater reductions in risk of CVD events, explaining most heterogeneity between trials. The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 53. Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited. We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence. There was little or no effect of reducing saturated fats on non-fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low-quality evidence), but effects on total (fatal or non-fatal) myocardial infarction, stroke and CHD events (fatal or non-fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes.

AUTHORS' CONCLUSIONS

The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events. Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies, while effects of replacement with monounsaturated fat are unclear. The reduction in combined cardiovascular events resulting from reducing saturated fat did not alter by study duration, sex or baseline level of cardiovascular risk, but greater reduction in saturated fat caused greater reductions in cardiovascular events.

Effects of total fat intake on body fatness in adults

BACKGROUND

The ideal proportion of energy from fat in our food and its relation to body weight is not clear. In order to prevent overweight and obesity in the general population, we need to understand the relationship between the proportion of energy from fat and resulting weight and body fatness in the general population.

OBJECTIVES

To assess the effects of proportion of energy intake from fat on measures of body fatness (including body weight, waist circumference, percentage body fat and body mass index) in people not aiming to lose weight, using all appropriate randomised controlled trials (RCTs) of at least six months duration.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, Clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (ICTRP) to October 2019. We did not limit the search by language.

SELECTION CRITERIA

Trials fulfilled the following criteria: 1) randomised intervention trial, 2) included adults aged at least 18 years, 3) randomised to a lower fat versus higher fat diet, without the intention to reduce weight in any participants, 4) not multifactorial and 5) assessed a measure of weight or body fatness after at least six months. We duplicated inclusion decisions and resolved disagreement by discussion or referral to a third party.

DATA COLLECTION AND ANALYSIS

We extracted data on the population, intervention, control and outcome measures in duplicate. We extracted measures of body fatness (body weight, BMI, percentage body fat and waist circumference) independently in duplicate at all available time points. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity, funnel plot analyses and GRADE assessment.

MAIN RESULTS

We included 37 RCTs (57,079 participants). There is consistent high-quality evidence from RCTs that reducing total fat intake results in small reductions in body fatness; this was seen in almost all included studies and was highly resistant to sensitivity analyses (GRADE high-consistency evidence, not downgraded). The effect of eating less fat (compared with higher fat intake) is a mean body weight reduction of 1.4 kg (95% confidence interval (CI) -1.7 to -1.1 kg, in 53,875 participants from 26 RCTs, I² = 75%). The heterogeneity was explained in subgrouping and meta-regression. These suggested that greater weight loss results from greater fat reductions in people with lower fat intake at baseline, and people with higher body mass index (BMI) at baseline. The size of the effect on weight does not alter over time and is mirrored by reductions in BMI (MD -0.5 kg/m², 95% CI -0.6 to -0.3, 46,539 participants in 14 trials, I² = 21%), waist circumference (MD -0.5 cm, 95% CI -0.7 to -0.2, 16,620 participants in 3 trials; I² = 21%), and percentage body fat (MD -0.3% body fat, 95% CI -0.6 to 0.00, P = 0.05, in 2350 participants in 2 trials; I² = 0%). There was no suggestion of harms associated with low fat diets that might mitigate any benefits on body fatness. The reduction in body weight was reflected in small reductions in LDL (-0.13 mmol/L, 95% CI -0.21 to -0.05), and total cholesterol (-0.23 mmol/L, 95% CI -0.32 to -0.14), with little or no effect on HDL cholesterol (-0.02 mmol/L, 95% CI -0.03 to 0.00), triglycerides (0.01 mmol/L, 95% CI -0.05 to 0.07), systolic (-0.75 mmHg, 95% CI -1.42 to -0.07) or diastolic blood pressure(-0.52 mmHg, 95% CI -0.95 to -0.09), all GRADE high-consistency evidence or quality of life (0.04, 95% CI 0.01 to 0.07, on a scale of 0 to 10, GRADE low-consistency evidence).

AUTHORS' CONCLUSIONS

Trials where participants were randomised to a lower fat intake versus a higher fat intake, but with no intention to reduce weight, showed a consistent, stable but small effect of low fat intake on body fatness: slightly lower weight, BMI, waist circumference and percentage body fat compared with higher fat arms. Greater fat reduction, lower baseline fat intake and higher baseline BMI were all associated with greater reductions in weight. There was no evidence of harm to serum lipids, blood pressure or quality of life, but rather of small benefits or no effect.

Reduction in saturated fat intake for cardiovascular disease

BACKGROUND

Reducing saturated fat reduces serum cholesterol, but effects on other intermediate outcomes may be less clear. Additionally, it is unclear whether the energy from saturated fats eliminated from the diet are more helpfully replaced by polyunsaturated fats, monounsaturated fats, carbohydrate or protein.

OBJECTIVES

To assess the effect of reducing saturated fat intake and replacing it with carbohydrate (CHO), polyunsaturated (PUFA), monounsaturated fat (MUFA) and/or protein on mortality and cardiovascular morbidity, using all available randomised clinical trials.

SEARCH METHODS

We updated our searches of the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid) and Embase (Ovid) on 15 October 2019, and searched Clinicaltrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) on 17 October 2019.

SELECTION CRITERIA

Included trials fulfilled the following criteria: 1) randomised; 2) intention to reduce saturated fat intake OR intention to alter dietary fats and achieving a reduction in saturated fat; 3) compared with higher saturated fat intake or usual diet; 4) not multifactorial; 5) in adult humans with or without cardiovascular disease (but not acutely ill, pregnant or breastfeeding); 6) intervention duration at least 24 months; 7) mortality or cardiovascular morbidity data available.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed inclusion, extracted study data and assessed risk of bias. We performed random-effects meta-analyses, meta-regression, subgrouping, sensitivity analyses, funnel plots and GRADE assessment.

MAIN RESULTS

We included 15 randomised controlled trials (RCTs) (16 comparisons, ~59,000 participants), that used a variety of interventions from providing all food to advice on reducing saturated fat. The included long-term trials suggested that reducing dietary saturated fat reduced the risk of combined cardiovascular events by 21% (risk ratio (RR) 0.79; 95% confidence interval (CI) 0.66 to 0.93, 11 trials, 53,300 participants of whom 8% had a cardiovascular event, I² = 65%, GRADE moderate-quality evidence). Meta-regression suggested that greater reductions in saturated fat (reflected in greater reductions in serum cholesterol) resulted in greater reductions in risk of CVD events, explaining most heterogeneity between trials. The number needed to treat for an additional beneficial outcome (NNTB) was 56 in primary prevention trials, so 56 people need to reduce their saturated fat intake for ~four years for one person to avoid experiencing a CVD event. In secondary prevention trials, the NNTB was 32. Subgrouping did not suggest significant differences between replacement of saturated fat calories with polyunsaturated fat or carbohydrate, and data on replacement with monounsaturated fat and protein was very limited. We found little or no effect of reducing saturated fat on all-cause mortality (RR 0.96; 95% CI 0.90 to 1.03; 11 trials, 55,858 participants) or cardiovascular mortality (RR 0.95; 95% CI 0.80 to 1.12, 10 trials, 53,421 participants), both with GRADE moderate-quality evidence. There was little or no effect of reducing saturated fats on non-fatal myocardial infarction (RR 0.97, 95% CI 0.87 to 1.07) or CHD mortality (RR 0.97, 95% CI 0.82 to 1.16, both low-quality evidence), but effects on total (fatal or non-fatal) myocardial infarction, stroke and CHD events (fatal or non-fatal) were all unclear as the evidence was of very low quality. There was little or no effect on cancer mortality, cancer diagnoses, diabetes diagnosis, HDL cholesterol, serum triglycerides or blood pressure, and small reductions in weight, serum total cholesterol, LDL cholesterol and BMI. There was no evidence of harmful effects of reducing saturated fat intakes.

AUTHORS' CONCLUSIONS

The findings of this updated review suggest that reducing saturated fat intake for at least two years causes a potentially important reduction in combined cardiovascular events. Replacing the energy from saturated fat with polyunsaturated fat or carbohydrate appear to be useful strategies, while effects of replacement with monounsaturated fat are unclear. The reduction in combined cardiovascular events resulting from reducing saturated fat did not alter by study duration, sex or baseline level of cardiovascular risk, but greater reduction in saturated fat caused greater reductions in cardiovascular events.

Educational interventions on nutrition among older adults: A systematic review and meta-analysis of randomized clinical trials

Poor nutrition is a major risk factor for non-communicable diseases and nutritional deficiencies. Dietary interventions have been proposed to improve eating habits. The aim of this systematic review is to evaluate the efficacy of randomized clinical trials of nutritional interventions in food habits among older people. A systematic literature review using the MEDLINE, LILACS, Scopus, Cochrane Library, Web of Science and Google Scholar databases was conducted, according to PRISMA guidelines. The keywords were: food and nutrition education OR educación alimentaria y nutricional OR educação alimentar e nutricional AND clinical trial OR ensayo clínico OR ensaio clínico AND elderly OR aged OR anciano OR idoso AND human OR seres humanos. The pooled standardized mean differences (SMD) and 95 % confidence intervals (CIs) were estimated using a random-effects model. Heterogeneity among studies was assessed using I² tests. After screening based on the title and abstract, and a full-text assessment, 11 studies remained. Results of pooling eleven studies were as follows: SMD = 0.25 (95 % CI = 0.15 - 0.34; I² = 0,0%) for vegetable, SMD = 0.18 (95 % CI = 0.08 - 0.27; I² = 0,0%) for fruit and SMD = 0.27 (95 % CI = 0.18 - 0.36; I² = 58,3%) for fibre intake. Our results suggest that nutritional interventions were effective in increasing vegetable, fruit and fibre intake. However, these results should be analyzed carefully, due to the small number of studies included in the meta-analysis. Further studies should be encouraged due to the aging process.

Intermittent fasting, Paleolithic, or Mediterranean diets in the real world: exploratory secondary analyses of a weight-loss trial that included choice of diet and exercise

BACKGROUND

Intermittent fasting (IF) and Paleolithic (Paleo) diets produce weight loss in controlled trials, but minimal evidence exists regarding long-term efficacy under free-living conditions without intense dietetic support.

OBJECTIVES

This exploratory, observational analysis examined adherence, dietary intake, weight loss, and metabolic outcomes in overweight adults who could choose to follow Mediterranean, IF, or Paleo diets, and standard exercise or high-intensity interval training (HIIT) programs, as part of a 12-mo randomized controlled trial investigating how different monitoring strategies influenced weight loss (control, daily self-weighing, hunger training, diet/exercise app, brief support).

METHODS

A total of 250 overweight [BMI (in kg/m2) ≥27] healthy adults attended an individualized dietary education session (30 min) relevant to their self-selected diet. Dietary intake (3-d weighed diet records), weight, body composition, blood pressure, physical activity (0, 6, and 12 mo), and blood indexes (0 and 12 mo) were assessed. Mean (95% CI) changes from baseline were estimated using regression models. No correction was made for multiple tests.

RESULTS

Although 54.4% chose IF, 27.2% Mediterranean, and 18.4% Paleo diets originally, only 54% (IF), 57% (Mediterranean), and 35% (Paleo) participants were still following their chosen diet at 12 mo (self-reported). At 12 mo, weight loss was -4.0 kg (95% CI: -5.1, -2.8 kg) in IF, -2.8 kg (-4.4, -1.2 kg) in Mediterranean, and -1.8 kg (-4.0, 0.5 kg) in Paleo participants. Sensitivity analyses showed that, due to substantial dropout, these may be overestimated by ≤1.2 kg, whereas diet adherence increased mean weight loss by 1.1, 1.8, and 0.3 kg, respectively. Reduced systolic blood pressure was observed with IF (-4.9 mm Hg;  -7.2, -2.6 mm Hg) and Mediterranean (-5.9 mm Hg; -9.0, -2.7 mm Hg) diets, and reduced glycated hemoglobin with the Mediterranean diet (-0.8 mmol/mol; -1.2, -0.4 mmol/mol). However, the between-group differences in most outcomes were not significant and these comparisons may be confounded due to the nonrandomized design.

CONCLUSIONS

Small differences in metabolic outcomes were apparent in participants following self-selected diets without intensive ongoing dietary support, even though dietary adherence declined rapidly. However, results should be interpreted with caution given the exploratory nature of analyses. This trial was registered with the Australian New Zealand Clinical Trials Registry as ACTRN12615000010594 at https://www.anzctr.org.au.

The Effects of Diet and Dietary Interventions on the Quality of Life among Breast Cancer Survivors: A Cross-Sectional Analysis and a Systematic Review of Experimental Studies

There is an ongoing need for solid evidence about the effects of healthy behaviors, and particularly diet, on the quality of life (QoL) among breast cancer survivors. We first conducted a cross-sectional study on 68 Italian stage I-III breast cancer survivors, to investigate the association of adherence to the Mediterranean diet (MD), physical activity and weight status with QoL. Adherence to MD and physical activity was assessed using structured questionnaires. QoL was assessed using the European Organization for the Research and Treatment of Cancer Quality-of-Life tools. We showed that low consumption of red meat and carbonated beverages, daily consumption of wine and high consumption of dishes seasoned with sofrito had beneficial effects on several QoL subscales. By contrast, using olive oil as the main culinary fat, low consumption of commercial sweets and high consumption of nuts were associated with negative effects. Overall, these findings resulted in a null effect of adherence to MD on QoL. Furthermore, we observed better QoL sub-scores among women who performed moderate physical activity (i.e., diarrhea) and those who were underweight/normal weight (i.e., physical functioning and dyspnea) if compared with their counterparts (p-values ≤ 0.003 after correction for multiple comparison). Next, we performed a systematic review of nine experimental studies to summarize whether dietary interventions might improve QoL among breast cancer patients. All the studies demonstrated significant improvements in overall QoL and/or its subscales after the interventions. However, differences in study design, interventions and tools used for QoL assessment did not allow us to provide an overall estimate. Moreover, only a single-arm trial evaluated the effect of an exclusive dietary-based intervention, while others combined dietary recommendations with physical activity and weight loss programs. For these reasons, our study encourages more efforts to improve the robustness of current evidence, through more homogenous tools, larger population-based studies and further randomized controlled trials.

Fatty acid profiles in erythrocyte membranes following the Mediterranean diet - data from a multicenter lifestyle intervention study in women with hereditary breast cancer (LIBRE)

BACKGROUND & AIMS

Evidence-based concepts to prevent breast cancer in women with BRCA1/2 mutations are limited. Adherence to a Mediterranean diet (MedD) has been associated with a lower risk for breast cancer, possibly due to a favorable fatty acid (FA) intake. Here, we studied in an at-risk population the effect of a lifestyle intervention that included the MedD on FA composition in red blood cell membranes (RBCM).

METHODS

Data derived from the German multicenter trial LIBRE, from which 68 women were randomized into an intervention group (IG) trained for MedD and increased physical activity for 12 months, and a usual care control group (CG). Adherence to the diet was assessed after 3 and 12 months using the validated Mediterranean Diet Adherence Screener (MEDAS) and a food frequency questionnaire. RBCM FA were analyzed by gas chromatography with mass spectrometry.

RESULTS

The MEDAS was increased in both groups after 3 months (IG: P < 0.001; CG: P = 0.004), and remained increased only in the IG after 12 months (P < 0.001). The food frequency questionnaire revealed an increased intake of omega-3 (n-3) FA at month 3 and month 12 in the IG (both P < 0.01), but not in the CG, in which intake of energy, protein and saturated FA decreased. In both groups n-6 FA in the RBCM decreased (P < 0.001), while n-9 FA increased (P < 0.001) and n-3 FA were unchanged. Women with higher consumption of fish had higher amounts of n-3 fatty acids in the RBCM. The MEDAS was inversely correlated with n-6 fatty acids.

CONCLUSIONS

The RBCM FA composition was associated with dietetic parameters related to the MedD. Adherence to the MedD resulted in an altered, likely favorable FA composition. Our data suggest selected FA as biomarkers to monitor compliance to a dietetic intervention such as the MedD.

CLINICAL TRIAL REGISTRY

The trial is registered at ClinicalTrials.gov (reference: NCT02087592).

Methods for the Selection of Covariates in Nutritional Epidemiology Studies: A Meta-Epidemiological Review

BACKGROUND

Observational studies provide important information about the effects of exposures that cannot be easily studied in clinical trials, such as nutritional exposures, but are subject to confounding. Investigators adjust for confounders by entering them as covariates in analytic models.

OBJECTIVE

The aim of this study was to evaluate the reporting and credibility of methods for selection of covariates in nutritional epidemiology studies.

METHODS

We sampled 150 nutritional epidemiology studies published in 2007/2008 and 2017/2018 from the top 5 high-impact nutrition and medical journals and extracted information on methods for selection of covariates.

RESULTS

Most studies did not report selecting covariates a priori (94.0%) or criteria for selection of covariates (63.3%). There was general inconsistency in choice of covariates, even among studies investigating similar questions. One-third of studies did not acknowledge potential for residual confounding in their discussion.

CONCLUSION

Studies often do not report methods for selection of covariates, follow available guidance for selection of covariates, nor discuss potential for residual confounding.

Assessing Validity of Self-Reported Dietary Intake within a Mediterranean Diet Cluster Randomized Controlled Trial among US Firefighters

Collecting dietary intake data is associated with challenges due to the subjective nature of self-administered instruments. Biomarkers may objectively estimate the consumption of specific dietary items or help assess compliance in dietary intervention studies. Our aim was to use a panel of plasma and urine biomarkers to assess the validity of self-reported dietary intake using a modified Mediterranean Diet Scale (mMDS) among firefighters participating in Feeding America's Bravest (FAB), an MD cluster-randomized controlled trial. In our nested biomarker pilot study, participants were randomly selected from both the MD intervention group (n = 24) and the control group (n = 24) after 12-months of dietary intervention. At baseline data collection for the pilot study (t = 12-months of FAB), participants in the control group crossed-over to receive the MD intervention (active intervention) for 6-months. Participants in the intervention group continued in a self-sustained continuation phase (SSP) of the intervention. Food frequency questionnaires (FFQ), 13-item-mMDS questionnaires, 40 plasma fatty acids, inflammatory biomarkers and urinary hydroxytyrosol and tyrosol were analyzed at both time points. Spearman's correlation, t-tests and linear regression coefficients were calculated using SAS software. Overall, the mMDS derived from the FFQ was highly correlated with the specific 13-domain-mMDS (r = 0.74). The concordance between the two questionnaires for low and high adherence to MD was high for all the participants in the parent trial (κ = 0.76). After 6 months of intervention in the pilot study, plasma saturated fatty acid decreased in both groups (active intervention: -1.3 ± 1.7; p = 0.002; SSP: -1.12 ± 1.90; p = 0.014) and oleic acid improved in the SSP (p = 0.013). Intake of olive oil was positively associated with plasma omega-3 (p = 0.004) and negatively with TNF-α (p < 0.001) at baseline. Choosing olive oil as a type of fat was also associated with higher levels of plasma omega-3 (p = 0.019) at baseline and lower TNF-α (p = 0.023) at follow up. Intake of red and processed meats were associated with lower serum omega-3 (p = 0.04) and fish consumption was associated with lower IL-6 at baseline (p = 0.022). The overall mMDS was associated with an increase in plasma omega-3 (p = 0.021). Good correlation was found between nutrient intake from the FFQ and the corresponding plasma biomarkers (omega-3, EPA and DHA). In this MD randomized controlled trial, some key plasma biomarkers were significantly associated with key MD diet components and the overall mMDS supporting the validity of the mMDS questionnaire as well as compliance with the intervention.

Effect of changes in adherence to Mediterranean diet on nutrient density after 1-year of follow-up: results from the PREDIMED-Plus Study

BACKGROUND

The prevalence of overweight/obesity and related manifestations such as metabolic syndrome (MetS) is increasing worldwide. High energy density diets, usually with low nutrient density, are among the main causes. Some high-quality dietary patterns like the Mediterranean diet (MedDiet) have been linked to the prevention and better control of MetS. However, it is needed to show that nutritional interventions promoting the MedDiet are able to improve nutrient intake.

OBJECTIVE

To assess the effect of improving MedDiet adherence on nutrient density after 1 year of follow-up at the PREDIMED-Plus trial.

METHODS

We assessed 5777 men (55-75 years) and women (60-75 years) with overweight or obesity and MetS at baseline from the PREDIMED-Plus trial. Dietary changes and MedDiet adherence were evaluated at baseline and after 1 year. The primary outcome was the change in nutrient density (measured as nutrient intake per 1000 kcal). Multivariable-adjusted linear regression models were fitted to analyse longitudinal changes in adherence to the MedDiet and concurrent changes in nutrient density.

RESULTS

During 1-year follow-up, participants showed improvements in nutrient density for all micronutrients assessed. The density of carbohydrates (- 9.0%), saturated fatty acids (- 10.4%) and total energy intake (- 6.3%) decreased. These changes were more pronounced in the subset of participants with higher improvements in MedDiet adherence.

CONCLUSIONS

The PREDIMED-Plus dietary intervention, based on MedDiet recommendations for older adults, maybe a feasible strategy to improve nutrient density in Spanish population at high risk of cardiovascular disease with overweight or obesity.

Effects of a Mediterranean Eating Plan on the Need for Glucose-Lowering Medications in Participants With Type 2 Diabetes: A Subgroup Analysis of the PREDIMED Trial

OBJECTIVE

To examine the effects of two Mediterranean eating plans (Med-EatPlans) versus a low-fat eating plan on the need for glucose-lowering medications.

RESEARCH DESIGN AND METHODS

From the Prevención con Dieta Mediterránea (PREDIMED) trial, we selected 3,230 participants with type 2 diabetes at baseline. These participants were randomly assigned to one of three eating plans: Med-EatPlan supplemented with extra-virgin olive oil (EVOO), Med-EatPlan supplemented with mixed nuts, or a low-fat eating plan (control). In a subgroup (15%), the allocation was done in small clusters instead of using individual randomization, and the clustering effect was taken into account in the statistical analysis. In multivariable time-to-event survival models, we assessed two outcomes: 1) introduction of the first glucose-lowering medication (oral or injectable) among participants on lifestyle management at enrollment and 2) insulin initiation.

RESULTS

After a median follow-up of 3.2 years, in multivariable analyses adjusting for baseline characteristics and propensity scores, the hazard ratios (HRs) of starting a first glucose-lowering medication were 0.78 (95% CI 0.62-0.98) for Med-EatPlan + EVOO and 0.89 (0.71-1.12) for Med-EatPlan + nuts, compared with the control eating plan. After a median follow-up of 5.1 years, the adjusted HRs of starting insulin treatment were 0.87 (0.68-1.11) for Med-EatPlan + EVOO and 0.89 (0.69-1.14) for Med-EatPlan + nuts compared with the control eating plan.

CONCLUSIONS

Among participants with type 2 diabetes, a Med-EatPlan + EVOO may delay the introduction of new-onset glucose-lowering medications. The Med-EatPlan did not result in a significantly lower need for insulin.

Benefits of the Mediterranean diet: Epidemiological and molecular aspects

More than 50 years after the Seven Countries Study, a large number of epidemiological studies have explored the relationship between the Mediterranean diet (MD) and health, through observational, case-control, some longitudinal and a few experimental studies. The overall results show strong evidence suggesting a protective effect of the MD mainly on the risk of cardiovascular disease (CVD) and certain types of cancer. The beneficial effects have been attributed to the types of food consumed, total dietary pattern, components in the food, cooking techniques, eating behaviors and lifestyle behaviors, among others. The aim of this article is to review and summarize the knowledge derived from the literature focusing on the benefits of the MD on health, including those that have been extensively investigated (CVD, cancer) along with more recent issues such as mental health, immunity, quality of life, etc. The review begins with a brief description of the MD and its components. Then we present a review of studies evaluating metabolic biomarkers and genotypes in relation to the MD. Other sections are dedicated to observation and intervention studies for various pathologies. Finally, some insights into the relationship between the MD and sustainability are explored. In conclusion, the research undertaken on metabolomics approaches has identified potential markers for certain MD components and patterns, but more investigation is needed to obtain valid measures. Further evaluation of gene-MD interactions are also required to better understand the mechanisms by which the MD diet exerts its beneficial effects on health. Observation and intervention studies, particularly PREDIMED, have provided invaluable data on the benefits of the MD for a wide range of chronic diseases. However further research is needed to explore the effects of other lifestyle components associated with Mediterranean populations, its environmental impact, as well as the MD extrapolation to non-Mediterranean contexts.

Changes in arginine are inversely associated with type 2 diabetes: A case-cohort study in the PREDIMED trial

The associations between arginine-based metabolites and incident type 2 diabetes (T2D) are unknown. We employed a case-cohort design, nested within the PREDIMED trial, to examine six plasma metabolites (arginine, citrulline, ornithine, asymmetric dimethylarginine [ADMA], symmetric dimethylarginine [SDMA] and N-monomethyl-l-arginine [NMMA]) among 892 individuals (251 cases) for associations with incident T2D and insulin resistance. Weighted Cox models with robust variance were used. The 1-year changes in arginine (adjusted hazard ratio [HR] per SD 0.68, 95% confidence interval [CI] 0.49, 0.95; Q4 vs. Q1 0.46, 95% CI 0.21, 1.04; P trend = 0.02) and arginine/ADMA ratio (adjusted HR per SD 0.73, 95% CI 0.51, 1.04; Q4 vs. Q1 0.52, 95% CI 0.22, 1.25; P trend = 0.04) were associated with a lower risk of T2D. Positive changes of citrulline and ornithine, and negative changes in SDMA and arginine/(ornithine + citrulline) were associated with concurrent 1-year changes in homeostatic model assessment of insulin resistance. Individuals in the low-fat-diet group had a higher risk of T2D for 1-year changes in NMMA than individuals in Mediterranean-diet groups (P interaction = 0.02). We conclude that arginine bioavailability is important in T2D pathophysiology.

Focus groups inform a mobile health intervention to promote adherence to a Mediterranean diet and engagement in physical activity among people living with HIV

Background

A personalized mobile health intervention (iSTEP) aims to promote a Mediterranean diet and increase physical activity, thereby improving neurocognitive functioning among persons living with HIV (PLWH). This article describes a qualitative study conducted to develop iSTEP for PLWH, including assessment of diet habits and preferences for tracking physical activity.

Method

Two focus groups, with seven and 13 PLWH respectively, discussed barriers and facilitators of a healthy diet and provided feedback to refine iSTEP components, including the feasibility of using a Fitbit and the content of text messages designed to encourage improved diet and physical activity.

Results

Focus group discussions revealed several healthy diet barriers, including housing instability, time required for food preparation, cost of healthy food, depression, gastrointestinal issues, physical disability, and changes in appetite since HIV diagnosis. Participant-identified healthy diet facilitators included affordable price options for healthy food, a structured food plan, desire to modify appearance or weight, access to medical professionals, motivation for disease prevention, and social support. Participants endorsed wearing a Fitbit on the wrist and receiving text messages as useful methods to monitor and encourage a better diet and greater physical activity.

Conclusions

These findings assisted the expansion of a mobile health intervention that promotes health behaviors in order to improve neurocognitive outcomes among PLWH.

Trial registration

NCT03123731, prospectively registered on ClinicalTrials.gov, April 21, 2017.

Effectiveness of A Multifactorial Intervention in Increasing Adherence to the Mediterranean Diet among Patients with Diabetes Mellitus Type 2: A Controlled and Randomized Study (EMID Study)

The Mediterranean diet (MD) is recognized as one of the healthiest dietary patterns and has benefits such as improving glycaemic control among patients with type 2 diabetes (T2DM). Our aim is to assess the effectiveness of a multifactorial intervention to improve adherence to the MD, diet quality and biomedical parameters. The EMID study is a randomized and controlled clinical trial with two parallel groups and a 12-month follow-up period. The study included 204 subjects between 25⁻70 years with T2DM. The participants were randomized into intervention group (IG) and control group (CG). Both groups received brief advice about healthy eating and physical activity. The IG participants additionally took part in a food workshop, five walks and received a smartphone application for three months. The population studied had a mean age of 60.6 years. At the 3-month follow-up visit, there were improvements in adherence to the MD and diet quality of 2.2 and 2.5 points, compared to the baseline visit, respectively, in favour of the IG. This tendency of the improvement was maintained, in favour of the IG, at the 12-month follow-up visit. In conclusion, the multifactorial intervention performed could improve adherence to the MD and diet quality among patients with T2DM.

A Community Program of Integrated Care for Frail Older Adults: +AGIL Barcelona

OBJECTIVES

To assess the 3-month impact on physical function of a program for community-dwelling frail older adults, based on the integration of primary care, geriatric medicine, and community resources, implemented in "real life".

DESIGN

Interventional cohort study.

SETTING

Primary care in Barcelona, Spain.

PARTICIPANTS

Individuals aged ≥80 years (n=134), presenting at least one sign of frailty (i.e., slow gait speed, weakness, memory complaints, involuntary weight loss, poor social support).

INTERVENTION

After frailty screening by the primary care team, candidates were referred to a geriatric team (geriatrician + physical therapist), who performed a comprehensive geriatric assessment and designed a tailored multidisciplinary intervention in the community, including a) multi-modal physical activity (PA) sessions, b) promotion of adherence to a Mediterranean diet c) health education and d) medication review.

MEASUREMENTS

Participants were assessed based on a comprehensive geriatric assessment including physical performance (Short Physical Performance Battery -SPPB- and gait speed), at baseline and at a three month follow-up.

RESULTS

A total of 112 (83.6%) participants (mean age=80.8 years, 67.9% women) were included in this research. Despite being independent in daily life, participants' physical performance was impaired (SPPB=7.5, SD=2.1, gait speed=0.71, SD=0.20 m/sec). After three months, 90.2% of participants completed ≥7.5 physical activity sessions. The mean improvements were +1.47 (SD 1.64) points (p<0.001) for SPPB, +0.08 (SD 0.13) m/sec (p<0.001) for gait speed, -5.5 (SD 12.10) sec (p<0.001) for chair stand test, and 53% (p<0.001) improved their balance. Results remained substantially unchanged after stratifying the analyses according to the severity of frailty.

CONCLUSIONS

Our results suggested that a "real-world" multidisciplinary intervention, integrating primary care, geriatric care, and community services may improve physical function, a marker of frailty, within 3 months. Further studies are needed to address the long-term impact and scalability of this implementation program.