Energy balance measurement: when something is not better than nothing

Improved food habits and anthropometry among primary school children following a novel healthy eating programme

OBJECTIVE

Assess longer-term changes in food habits and anthropometry among Grades 1-2 primary school students from four public schools in Colombo, Sri Lanka, following a 3-week programme including a classroom-based motivational storybook discussion and self-monitoring food diary (FD).

METHODS

This follow-up study assessed changes from baseline (pre-intervention) BMI z-scores and food habits (increased healthy food-item consumption/decreased unhealthy food-item consumption reflected by an increase in FD score) and parental perceptions (anonymous questionnaires) among 863 students (aged 6-8 years), between 9 and 12 months after completing the programme (November 2019-February 2020).

RESULTS

Food habits showed sustained improvement from baseline mean FD score (baseline vs. follow-up: 51 ± 23% vs. 67 ± 22%, p < 0.001), with children from all BMI subgroups (underweight [UW], normal weight [NW], overweight [OW] and obesity [OB]) showing a significant increase in FD scores (ranging from 14.1% to 17.2%, p < 0.001). BMI z-scores increased in children living with UW (-2.85 to -2.21, p < 0.00) and NW (-0.70 to -0.57, p < 0.001), but did not change in children with OW (+1.5 to +1.49, p = 0.83) and OB (+2.85 to +2.21, p = 0.19). Most parents (n = 497, 97.8%) reported satisfaction with programme outcomes.

CONCLUSION

This programme led to sustained improvement in food habits among young primary school children from all BMI categories, increase in BMI towards the median among children living with UW and NW, and stabilization of BMI in children with OW and OB, suggesting it as a useful tool for improving nutritional status of young children in low- and middle-income countries (LMIC) facing the double burden of under- and overnutrition.

Energy Balance and Dietary Intake in Young Rugby Players during a Pre-Season Micro-Cycle: A Cluster Analysis

Rugby players must develop excellent levels of conditioning during adolescence. However, this pivotal period of life is also characterized by a surge in biological growth, which further increases the energy and nutritional requirements of this population. This study examined within-individual differences in energy intake (EI) and energy balance (EB) of 46 young rugby players during a pre-season micro-cycle. Two clusters were identified with significantly different characteristics and EB states, suggesting that young rugby players adjust their EI to match their body composition goals. The first cluster is characterized by players with a low body fat% (12.87 ± 2.53). They had a positive EB (330 ± 517 kcal), suggesting a goal of increasing muscle mass. Conversely, the second cluster is characterized by a higher body fat% (23.1 ± 1.6, p < 0.005) and reported a negative, lower EB (-683 ± 425 kcal, p < 0.005), suggesting a goal focused on reducing fat mass. Although our study provides more optimistic results than previous ones regarding the high risk of inadequate EI in young rugby players, we emphasize the importance of rigorous nutritional support, especially for players aiming to lose weight, to avoid severe caloric restriction, as well as the downstream effects of such practices on their nutritional status, given the higher risk of macro- (e.g., CHO < 6 g/kg/d) and micronutrient (e.g., iron < 11 mg/d, calcium < 1300 mg/d, vitamin D < 5 mg/d) deficiencies.

The Effect of the Menstrual Cycle on Energy Intake: A Systematic Review and Meta-analysis

CONTEXT

Energy intake may differ across the menstrual cycle, with some studies identifying greater energy intake in the luteal phase (LP) compared with the follicular phase (FP) and others finding no clear differences. To date, no study has systematically synthesized the available data to draw more definite conclusions while considering any methodological inconsistencies between studies.

OBJECTIVE

The aim was to conduct a systematic review/meta-analysis in an effort to determine if there are differences in energy intake between the FP and LP.

DATA SOURCES

A systematic search strategy was developed and the search was conducted in 5 databases for studies that investigated any changes in energy intake across menstrual phases.

DATA EXTRACTION

Using Covidence, studies were identified and included if they contained individuals between the ages of 18 and 45 years, maintained an average body mass index (BMI) of 18.5-25 kg/m2, had no history of disordered eating, and included energy intake and menstrual cycle measurements in the FP and LP.

DATA ANALYSIS

Effect sizes were calculated for each study and a random-effects model was used to pool the results of each study.

RESULTS

Fifteen datasets were included consisting of 330 female participants with a mean age of 26 ± 4 years and mean BMI of 22.4 ± 2.3 kg/m2. Overall, there was a statistically significant difference (standardized mean difference = 0.69; P = .039) with increased energy intake in the LP compared with the FP (crude 168 kcal⋅d-1 average difference between phases).

CONCLUSION

Energy intake was found to be greater in the LP compared with the FP, providing insight into the effect of the menstrual cycle on energy intake. However, there were repeated methodological inconsistencies and future work should strive to utilize best practices for both energy intake measurement and menstrual phase specification.

Effect of Early Time-Restricted Eating on Metabolic Markers and Body Composition in Individuals with Overweight or Obesity

This study aimed to evaluate the effect of early time-restricted eating (eTRE) on metabolic markers and body composition in individuals with overweight or obesity. Seventeen subjects completed a randomized, crossover, and controlled clinical trial. Twelve women and five men participated, with a mean age of 25.8 ± 10.0 years and a BMI of 32.0 ± 6.3 kg/m2. The eTRE intervention included 16 h of fasting (3:00 pm to 7:00 am) and 8 h of ad libitum eating (7:00 am to 03:00 pm) (16:8). The trial included four weeks of interventions followed by a four-week washout period. Body weight, waist and hip circumferences, and body composition measurements were taken. Additionally, a venous blood sample was collected for biochemical determinations. In a before-after analysis, eTRE induced a reduction in BW and BMI in women but this was not significant when compared to the control group. eTRE did not modify any other anthropometric measurements, fasting biochemical parameters, glycemic and insulinemic responses, blood pressure, or subjective appetite. In conclusion, eTRE did not induce beneficial effects on the glycemic and lipid metabolisms, body composition, subjective appetite, or blood pressure. These findings may be attributed to the special characteristics of the population and the short intervention period.

Guilt by association: Plant-based foods can be incorporated into both healthy and unhealthy plant-based diet indices associated with coronary heart disease

Background

One approach to test for differential associations between plant foods with health uses a scoring approach: foods categorized into animal or 'healthy' plant-based or 'unhealthy' plant-based groups to construct a plant-based diet index (PDI), healthy PDI (hPDI), and unhealthy PDI (uPDI).

Objective

To evaluate robustness of associations between diet indices and incident coronary heart disease (CHD) risk when recategorizing food groups in indices.

Methods

Using REasons for Geographic and Racial Differences in Stroke (REGARDS) data, we replicated a published use of the scoring approach. Using Cox proportional hazards regression, we assessed ramifications of the following on associations between diet indices and CHD risk: 1) reconfiguring foods within and among food groups, using potatoes as an example, 2) leave-one-out analysis for each of 12 plant-based food groups, and 3) agnostically redefining each food group as 'healthy' or 'unhealthy'.

Results

Over 153,286 person-years of follow-up, there were 868 cases of CHD. Replication analyses did not reach statistical significance. General patterns of magnitude of hazard ratios (HRs) in replication and reconfiguration models were PDI HRs < hPDI HRs < uPDI HRs for women, and hPDI < PDI < uPDI for men. Five models reconfiguring potatoes resulted in small, varied differences in PDI, hPDI, and uPDI associations. Leave-one-out analyses resulted in greater variation of associations between indices and CHD. In agnostic models, each plant-based food group was classified in indices as 'healthy' and 'unhealthy' with statistically significant beneficial or deleterious associations with CHD. Averaged over 4,096 models, HRs' shifts were small when food groups were moved between 'healthy' and 'unhealthy'.

Conclusion

Statistically significant associations between hPDI, uPDI, and PDI and incident CHD were not replicated. Small perturbations of the scoring approach had varied impacts on HRs. Agnostically constructing diet indices demonstrated the potential for guilt (or benefit) by association: any of the food groups we studied could be categorized with others in an index showing beneficial or deleterious associations.

Secular trends and determinants of ad libitum energy intake measured in a research setting from 1999-2020

Introduction

Historically, secular and seasonal trend analyses have been examined using self-report measures of intake. Rarely are objective measures and known determinants of dietary intake used in these analyses. Our objective was to quantify the seasonal and secular differences in an objective ad libitum intake paradigm while considering the contribution of determinants, such as fat-free mass (FFM) index and spontaneous physical activity (SPA) limited to the restricted space of a whole-room calorimeter.

Methods

For this study, recruitment of N = 292 healthy, diabetes free, adults occurred from 1999 to 2020. Assessment during their 10-day stay included body composition (by DXA), SPA (by an approximately 24-h stay in whole-room calorimetry), and ad libitum intake (by a vending machine for 3 days). This secondary analysis used general linear models (GLM) to investigate secular and seasonal differences while adjusting for sex, age, FFM index, FM (fat mass) index, SPA, and race/ethnicity.

Results

FFM index and SPA were positively associated with all intake measures (p < 0.05). In all adjusted seasonal models, season did not affect intake. Adjusted secular trends models (kcals/year) demonstrated a decrease in total kcals (β = -55), intake as percent weight maintaining energy needs (β = -2), protein kcals (β = -10), fat kcals (β = -27), and carbohydrates kcals (β = -22) (all p < 0.05). After further adjustment for SPA, significance remained in all intake measures (p < 0.05). Secular trends in body composition revealed no changes in weight, BMI, and percent body fat (all p > 0.20).

Discussion

Our results indicate that over time, ad libitum intake decreased in this controlled research setting and remained significant even after accounting for positive determinants of intake. A significant ad libitum decrease, coupled with no change in body composition, may highlight a participant bias toward calorie restriction in a controlled setting over time and deserves further investigation.

Misstatements, misperceptions, and mistakes in controlling for covariates in observational research

We discuss 12 misperceptions, misstatements, or mistakes concerning the use of covariates in observational or nonrandomized research. Additionally, we offer advice to help investigators, editors, reviewers, and readers make more informed decisions about conducting and interpreting research where the influence of covariates may be at issue. We primarily address misperceptions in the context of statistical management of the covariates through various forms of modeling, although we also emphasize design and model or variable selection. Other approaches to addressing the effects of covariates, including matching, have logical extensions from what we discuss here but are not dwelled upon heavily. The misperceptions, misstatements, or mistakes we discuss include accurate representation of covariates, effects of measurement error, overreliance on covariate categorization, underestimation of power loss when controlling for covariates, misinterpretation of significance in statistical models, and misconceptions about confounding variables, selecting on a collider, and p value interpretations in covariate-inclusive analyses. This condensed overview serves to correct common errors and improve research quality in general and in nutrition research specifically.

Should carbohydrate-modified diets be the first option for weight loss in people with impaired glucose metabolism? A scoping review

While the "precision nutrition" movement is at an early stage of development, several investigations have compared low-fat versus carbohydrate (CHO)-modified diets (i.e., low-or-reduced-CHO, low glycemic index/load diets, and high-fiber) in people with normal versus impaired glucose metabolism. The purpose of this scoping review was to summarize evidence in support of the hypothesis that CHO-modified diets are more effective for weight loss among people with impaired glucose metabolism. Fifteen articles were included in this review: seven retrospective analyses of randomized clinical trials and eight prospective randomized clinical trials with prespecified hypotheses related to a diet (low-fat vs. CHO-modified) × phenotype (normal vs. impaired) interaction. Evidence in support of the hypothesis was identified in six of seven retrospective and three of eight prospective studies, which led to a recommendation of CHO-modified diets as a first-line option for people with impaired glucose metabolism. However, the evidence in support of this recommendation is relatively weak, and dietary prescriptions should consider additional contextual information that may influence overall dietary adherence. Additional and rigorous research using innovative randomized experimental approaches is needed for stronger dietary weight loss recommendations based on pretreatment glycemic status.

Low- and high-load resistance training exercise to volitional fatigue generate exercise-induced appetite suppression

Research on exercise-induced appetite suppression often does not include resistance training (RT) exercise and only compared matched volumes.

PURPOSE

To compare the effects of low-load and high-load RT exercise completed to volitional fatigue on appetite-regulation.

METHODS

11 resistance-trained males (24 ± 2 y) completed 3 sessions in a crossover experimental design: 1) control (CTRL); 2) RT exercise at 30% 1-repetition maximum (RM); and 3) RT exercise at 90% 1-RM. RT sessions consisted of 3 sets of 5 exercises completed to volitional fatigue. Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), active peptide tyrosine (PYY), lactate, and subjective appetite perceptions were measured pre-exercise, 0-, 60-, and 120-min post-exercise. Energy intake was recorded the day before, of, and after each session.

RESULTS

Lactate was elevated following both 30% (0-, 60-, 120-min post-exercise) and 90% (0-, 60-min post-exercise; P < 0.001, d > 3.92) versus CTRL, with 30% greater than 90% (0-min post-exercise; P = 0.011, d = 1.14). Acylated ghrelin was suppressed by 30% (P < 0.007, d > 1.22) and 90% (P < 0.028, d > 0.096) post-exercise versus CTRL, and 30% suppressed concentrations versus 90% (60-min post-exercise; P = 0.032, d = 0.95). There was no effect on PYY (P > 0.171, ηp2 <0.149) though GLP-1 was greater at 60-min post-exercise in 90% (P = 0.052, d = 0.86) versus CTRL. Overall appetite was suppressed 0-min post-exercise following 30% and 90% versus CTRL (P < 0.013, d > 1.10) with no other differences (P > 0.279, d < 0.56). There were no differences in energy intake (P > 0.101, ηp2 <0.319).

CONCLUSIONS

RT at low- and high-loads to volitional fatigue induced appetite suppression coinciding with changes in acylated ghrelin though limited effects on anorexigenic hormones or free-living energy intake were present.

ONE QUALITY concept: a narrative perspective to unravel nutritional challenges, controversies, and the imperative need of transforming our food systems

Ensuring a healthy and sustainable diet for all should be a global priority, and to achieve this goal the food system requires substantial changes. Adopting a one-size-fits-all approach is not feasible, and we need to consider the cultural particularities of each geography and not try to export models that work in one place but may be unsustainable in others. Our discussion will center on two key aspects within this overarching process: (a) the combination of a rigorous evidence-based approach with existing or proposed Nutritional Guidelines and policies required to realize the "ONE HEALTH" and "ONE QUALITY" concepts. Examining the Mediterranean diet and the latest findings on saturated fats will aid us in comprehending the necessary paradigm shift required to formulate new guidelines with substantial impact in preventing the rising prevalence of Non-Communicable Diseases worldwide; (b) the adequacy and scope of the data bank necessary to develop a global, science-based approach.

The impact of body composition on the degree of misreporting of food diaries

BACKGROUND/OBJECTIVES

Accurate assessments of energy intake (EI) are needed in lifestyle interventions to guarantee a negative energy balance (EB), thereby losing weight. This study aimed (1) to compare objectively measured and self-reported EI and (2) to determine the predictors of underreporting divided by sex, adiposity and BMI category.

METHODS

Seventy-three participants [mean (SD): 43.7 (9.2) years, BMI = 31.5 (4.5) kg/m2, 37% females] of the Champ4Life intervention were included in this study. EI was measured using the "intake-balance method" and self-reported through 3-day food records. Fat mass (FM) and fat-free mass (FFM) were measured by dual-energy X-ray absorptiometry. Bland-Altman analysis was performed to compare both EI assessments.

RESULTS

Self-reported EI was lower than measured EI during both neutral (-355 kcal/d) and negative EB (-570 kal/day). While no significant trends were observed for EI evaluation in either neutral (p = 0.315) or negative EB (p = 0.611), limits of agreement were wide (-1720 to 1010 and -1920 to 779 kcal/day, respectively). In females, the degree of misreporting (kcal/day and %) was predicted by weight (p = 0.032 and p = 0.039, respectively) and FM (p = 0.029 and p = 0.037, respectively). In males, only BMI (p = 0.036) was a predictor of misreporting (kcal/day).

CONCLUSION

Self-reported EI did not agree with measured EI. Our results show that larger body size was associated with higher levels of underestimation for EI (females only). Nevertheless, misreporting EI is a complex issue involving more associations than merely body composition. A deeper understanding could inform counseling for participants filling out food records in other to reduce misreporting and improve validity.

Ten weeks of low-volume walking training improve cardiometabolic health and body composition in sedentary postmenopausal women with obesity without affecting markers of bone metabolism

This study aimed to determine the effects of walking exercise to induce a mild energy deficit and to improve body composition and metabolic status in postmenopausal women (PMW) with obesity as means of minimizing endocrine disruption and maintaining bone health. Twenty-four PMW with obesity (age: 55.0 ± 3.7 y, BMI: 32.9 ± 4.2 kg/m2, percent body fat: 46.2 ± 3.6%) were randomly assigned into either exercise (n = 12) or control (n = 12) groups. Exercise group participated in a-10 week supervised progressive walking programme   and control group maintained regular habits. Pre- and post-training assessments included body composition, bone mass, peak oxygen uptake (V ˙ O2peak), osteocalcin, bone alkaline phosphatase (BAP), type I collagen cross-linked C-telopeptide (CTX)glucose, glycated haemoglobin (HbA1c)), leptin and adiponectin. Results: Following the training program, body weight (2.6%; p < 0.001), fat mass (4.5%; p = 0.002), resting glucose (6.8%; p = 0.017), and HbA1c (3.7%; p = 0.047) decreased, while relative V ˙ O2peak (16%; p < 0.001) increased in the exercise group. Leptin, adiponectin, CTX, osteocalcin or BAP did not change in either group. In conclusion, small dose of aerobic exercise improves key markers of metabolic health in PMW with obesity without negatively affecting markers of bone metabolism.

Twenty-Four-Hour Urinary Sugars Biomarker in a Vending Machine Intake Paradigm in a Diverse Population

Accurately measuring dietary sugars intake in large-scale epidemiological studies is necessary to understand dietary sugars' true impact on health. Researchers have developed a biomarker that can be used to assess total sugars intake. Our objective is to test this biomarker in diverse populations using an ad libitum intake protocol. Healthy adult participants (n = 63; 58% Indigenous Americans/Alaska Natives; 60% male; BMI (mean ± SD) = 30.6 ± 7.6 kg.m2) were admitted for a 10-day inpatient stay. On day 2, body composition was measured by DXA, and over the last 3 days, ad libitum dietary intake was measured using a validated vending machine paradigm. Over the same days, participants collected daily 24 h urine used to measure sucrose and fructose. The 24 h urinary sucrose and fructose biomarker (24hruSF) (mg/d) represents the sum of 24 h urinary sucrose and fructose excretion levels. The association between the 3-day mean total sugars intake and log 24uSF level was assessed using the Pearson correlation. A linear mixed model regressing log-biomarker on total sugars intake was used to investigate further the association between biomarker, diet, and other covariates. Mean (S.D.) total sugars intake for the group was 197.7 g/d (78.9). Log 24uSF biomarker was moderately correlated with total sugars intake (r = 0.33, p = 0.01). In stratified analyses, the correlation was strongest in females (r = 0.45, p = 0.028), the 18-30 age group (r = 0.44, p = 0.079), Indigenous Americans (r = 0.51, p = 0.0023), and the normal BMI category (r = 0.66, p = 0.027). The model adjusted for sex, age, body fat percent, and race/ethnicity demonstrated a statistically significant association between 24uSF and total sugars intake (β = 0.0027, p < 0.0001) and explained 31% of 24uSF variance (marginal R2 = 0.31). Our results demonstrated a significant relationship between total sugars intake and the 24uSF biomarker in this diverse population. However, the results were not as strong as those of controlled feeding studies that investigated this biomarker.

Psychometric validation of four-item exercise identity and healthy-eater identity scales and applications in weight loss maintenance

BACKGROUND

Identifying as someone who engages in health promoting behaviors like healthy eating and exercising may be associated with sustained engagement in those behaviors, but reliable and valid instruments are needed to improve the rigor of this research. Two studies were conducted to (1) examine the psychometric properties of a four-item exerciser identity measure (4-EI) and an adapted healthy-eater identity measure (4-HEI) and (2) examine differences in identity strengths across categories of weight loss success.

METHODS

Data from 1,709 community dwelling adults in the International Weight Control Registry (IWCR) were used. A random half of the sample was used to assess the proposed unidimensional factor structure of the 4-EI and 4-HEI and examine convergent and discriminant validity using Spearman rank-order correlations. One-way ANOVA was used in the other random half of the sample to compare 4-EI and 4-HEI scores (-3 to + 3) across three self-defined weight loss categories ('Successful', 'Regain', and 'Unsuccessful') and those maintaining ≥ 5% weight loss for > 1 year vs. not.

RESULTS

Results support the unidimensional factor structure with all four items (eigenvalue scores > 2.89) as well as convergent and discriminant validity for both measures. Exercise identity was strongly correlated with self-reported physical activity (r (735) = 0.52, p <.001) and measures of autonomous motivation. Healthy eating identity was moderately correlated with cognitive restraint in eating (r (744) = 0.42, p <.001) and other measures predictive of eating behavior. 4-EI and 4-HEI are stronger in Successful (4-EI: M = 0.90, SD = 1.77; 4-HEI: M = 1.56 SD = 1.37) vs. Regain (4-EI: M=-0.18, SD = 1.68; 4-HEI: M =.57, SD = 1.48) and Unsuccessful (4-EI:M=-0.28, SD = 1.62; 4-HEI: M = 0.51, SD = 1.33) and those maintaining ≥ 5% weight loss (4-EI:M = 0.47, SD = 1.78; 4-HEI: M = 1.13, SD = 1.49) vs. not (4-EI:M=-0.27, SD = 1.66; 4-HEI: M = 0.53, SD = 1.47), p's < 0.001.

CONCLUSIONS

The 4-EI and 4-HEI have acceptable psychometric properties and can advance understanding of the role of identity in exercise and dietary behaviors and weight loss maintenance.

TRIAL REGISTRATION

The parent observational study, International Weight Control Registry (IWCR), for these sub-studies is registered in ClinicalTrials.gov (NCT04907396).

Interindividual variability in energy intake and expenditure during a weight loss intervention

INTRODUCTION

Behavioral compensations may occur as a response to a negative energy balance. The aim of this study was to explore the associations between changes in energy intake (EI) and changes in physical activity (PA, min/day; kcal/d) as a response to a weight loss (WL) intervention and to understand if interindividual differences occur in EI and energy expenditure (EE).

METHODS

Eighty-one participants [mean (SD): age = 42.8 (9.4)y, BMI = 31.2 (4.4)kg/m2, 37% females] divided in intervention (IG, n = 43) and control group (CG, n = 38) were included. The IG underwent a moderate energy restriction (300-500 kcal/d). EI was measured through the intake-balance method. Non-exercise PA (NEPA) and exercise (through logbook) were assessed by accelerometery. The EE in NEPA (NEAT) and in exercise (EiEE) was calculated by applying the Freedson Combination'98 algorithm over the time spent in these activities. Pearson correlations were performed in IG to examine associations between EE components, EI and body composition. To understand if interindividual differences were observed, the SD of individual response (SDIR) and the smallest worthwhile change (SWC, SDbaselineCG×0.2) were calculated.

RESULTS

Changes in EI [Δ EI, (kcal/d)] was negatively associated with Δ exercise (min/d:r = -0.413, p = 0.045; %:r = -0.846, p = 0.008) and with Δ EiEE (kcal/d:r = -0.488, p = 0.016; %:r = -0.859, p = 0.006). A negative correlation was found between Δ sedentary time and Δ NEPA (min/d:r = -0.622, p = 0.002; %:r = -0.487, p = 0.018). An interindividual variability was found for EI(SDIR = 151.6, SWC = 72.3) and EE (SDIR = 165, SWC = 134).

CONCLUSIONS

Decreases in EI were not associated to compensatory responses such as decreases in PA and/or increases in sedentary time. Interindividual variability was found for EI and EE. Nevertheless, behavioral compensations and the interindividual variability should be considered when implementing WL interventions, to increase the likelihood of achieving sustainable results. (clinicaltrials.gov ID: NCT03031951).

The Validity and Feasibility of Utilizing the Photo-Assisted Dietary Intake Assessment among College Students and Elderly Individuals in China

Dietary assessments hold significant importance within the field of public health. However, the current methods employed for dietary assessments face certain limitations and challenges that necessitate improvement. The aim of our study was to develop a reliable and practical dietary assessment tool known as photo-assisted dietary intake assessment (PAD). In order to evaluate its validity, we conducted an analysis on a sample of 71 college students' dinners at a buffet in a canteen. We compared estimates of food weights obtained through the 24-h recall (24 HR) or PAD method with those obtained through the weighing method; we also evaluated the feasibility of PAD for recording dinner intakes among a sample of college students (n = 76) and elderly individuals (n = 121). In addition, we successfully identified the dietary factors that have a significant impact on the bias observed in weight estimation. The findings of the study indicated that the PAD method exhibited a higher level of consistency with the weighing method compared to the 24 HR method. The discrepancy in D% values between cereals (14.28% vs. 40.59%, P < 0.05), vegetables (17.67% vs. 44.44%, P < 0.05), and meats (14.29% vs. 33.33%, P < 0.05) was clearly apparent. Moreover, a significant proportion of the food mass value acquired through the PAD method fell within the limits of agreement (LOAs), in closer proximity to the central horizontal line. Furthermore, vegetables, cereals, eggs, and meats, for which the primary importance lies in accuracy, exhibited a considerably higher bias with the 24 HR method compared to the PAD method (P < 0.05), implying that the PAD method has the potential to mitigate the quality bias associated with these food items in the 24 HR method. Additionally, the PAD method was well received and easily implemented by the college students and elderly individuals. In conclusion, the PAD method demonstrates a considerable level of accuracy and feasibility as a dietary assessment method that can be effectively employed across diverse populations.

Short-Term Effect of a Health Promotion Intervention Based on the Electronic 12-Hour Dietary Recall (e-12HR) Smartphone App on Adherence to the Mediterranean Diet Among Spanish Primary Care Professionals: Randomized Controlled Clinical Trial

BACKGROUND

The World Health Organization has called for addressing the growing burden of noncommunicable diseases (NCDs) by promoting healthy lifestyles among the population. Regarding patient health, primary care professionals (PCPs) are the first line of care who can positively influence patients' behavior and lifestyle habits. However, a significant percentage of PCPs do not lead a healthy lifestyle. Therefore, addressing their health behaviors may be the key to substantially increasing health promotion advice in general practice. The Mediterranean diet has been extensively studied, and there is strong evidence of it being a dietary pattern for the prevention of NCDs, in addition to its significant environmental, sociocultural, and local economics benefits.

OBJECTIVE

This study focused only on the dietary aspect of the PCPs' lifestyle. The primary objective was to evaluate the effect of using the Electronic 12-Hour Dietary Recall (e-12HR) smartphone app to improve diet, specifically to promote adherence to the Mediterranean diet (AMD), among PCPs. The secondary objectives were to establish the usability of the e-12HR app and to determine AMD among PCPs.

METHODS

An individual-level randomized, controlled, and single-blind clinical trial was conducted with 2 parallel groups: a control group (CG), using the nonfeedback version of the e-12HR app, and an intervention group (IG), using the feedback version of the e-12HR app. The level of human involvement was fully automated through the use of the app. There was a 28-day follow-up period. Participants were PCPs (medicine or nursing) recruited offline at one of the selected primary care centers (Andalusia, Spain, Southern Europe), of both sexes, over 18 years old, possessing a smartphone, and having smartphone literacy.

RESULTS

The study response rate was 73% (71 of 97 PCPs), with 27 (38%) women and 44 (62%) men: 40 (56%) PCPs in the CG and 31 (44%) in the IG. At baseline, AMD was medium (mean Mediterranean Diet Serving Score [MDSS] index 9.45, range 0-24), with 47 (66%) PCPs with a medium/high MDSS index. There were significant statistical improvements (CG vs IG, in favor of the IG) at week 4 (no significant statistical differences at baseline): +25.6% for the MDSS index (P=.002) and +213.1% for the percentage with a medium/high MDSS index (P=.001). In relation to specific food groups, there were significant statistical improvements for fruits (+33.8%, P=.02), vegetables (+352%, P=.001), nuts (+184%, P=.02), and legumes (+75.1%, P=.03). The responses to the usability rating questionnaire were satisfactory.

CONCLUSIONS

The results support recommending the use of the e-12HR app as a tool to contribute to improving diet and preventing NCDs among PCPs, while positively influencing patient dietary behavior and preventing diet-related NCDs among patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05532137; https://clinicaltrials.gov/study/NCT05532137.

Meat consumption & positive mental health: A scoping review

The objective of this scoping review was to examine the breadth of the existing literature on the relation between meat consumption or meat abstention and positive psychological functioning. In April 2022, we conducted a systematic search of online databases (PubMed, PsycINFO, CINAHL Plus, Medline, Cochrane Library, and Web of Science) for primary research examining positive psychological functioning in meat consumers and those who abstain from meat. Thirteen studies met the inclusion/exclusion criteria, representing 89,138 participants (54,413 females and 33,863 males) with 78,562 meat consumers and 10,148 meat abstainers (13-102 years) from multiple geographic regions. The primary outcomes were life satisfaction, "positive mental health", self-esteem, and vigor. The secondary outcomes were "meaning in life", optimism, positive emotions, and psychological well-being. Eight of the 13 studies demonstrated no differences between the groups on positive psychological functioning, three studies showed mixed results, and two studies showed that compared to meat abstainers, meat consumers had greater self-esteem, "positive mental health", and "meaning in life". Studies varied substantially in methods and outcomes. Although a small minority of studies showed that meat consumers had more positive psychological functioning, no studies suggested that meat abstainers did. There was mixed evidence for temporal relations, but study designs precluded causal inferences. Our review demonstrates the need for future research given the equivocal nature of the extant literature on the relation between meat consumption and meat abstention and positive psychological functioning.

Do macronutrient intakes affect obesity indices in Jordanian adults?

OBJECTIVE

To determine whether macronutrient intake is associated with novel obesity indices, including the conicity index (CI), body adiposity index (BAI), abdominal volume index (AVI), body roundness index (BRI), and weight-adjusted-waist index (WWI).

METHODOLOGY

A cross-sectional survey was conducted with 491 adults (344 males and 147 females) working at different universities in Jordan (July-December 2019). Daily intake of energy (kcal), carbohydrates (g), protein (g), and fat (g) was obtained using 24-h recalls collected over 2 days. Additionally, obesity indices were calculated.

RESULTS

Regardless of sex, energy, and carbohydrate intakes had a moderately significant positive association, whereas protein and fat intakes had a weakly significant association with BAI, AVI, and BRI. CI and WWI showed a weakly significant association with all macronutrients in males, a moderate correlation with energy and carbohydrate intake, and a weak association with fat and protein intake in females. Male participants had significant increases in the CI (T1 = 1.29 ± 0.01 vs. T3 = 1.36 ± 0.01, p = .018), AVI (T1 = 17.96 ± 0.52 vs. T3 = 22.81 ± 0.57, p = .011), and WWI (T1 = 10.72 ± 0.11 vs. T3 = 11.29 ± 0.09, p = .047) indices scores through the carbohydrate intake tertiles. Additionally, there was a significant increase in scores of AVI (T1 = 18.60 ± 0.56 vs. T3 = 21.42 ± 0.46, p = .048) and an almost significant increase in CI (T1 = 1.30 ± 0.01vs. T3 = 1.33 ± 0.01, p = .056) through the tertiles of protein intake.

CONCLUSION

Macronutrients were significantly associated with all indices. The effect of macronutrients on obesity indices is sex-based. Among men, CI, AVI, and WWI were the indices most affected by carbohydrate and protein intakes. Future studies should further investigate food sources and macronutrient quality.

Diet composition and energy intake in humans

Absolute energy from fats and carbohydrates and the proportion of carbohydrates in the food supply have increased over 50 years. Dietary energy density (ED) is primarily decreased by the water and increased by the fat content of foods. Protein, carbohydrates and fat exert different effects on satiety or energy intake (EI) in the order protein > carbohydrates > fat. When the ED of different foods is equalized the differences between fat and carbohydrates are modest. Covertly increasing dietary ED with fat, carbohydrate or mixed macronutrients elevates EI, producing weight gain and vice versa. In more naturalistic situations where learning cues are intact, there appears to be greater compensation for the different ED of foods. There is considerable individual variability in response. Macronutrient-specific negative feedback models of EI regulation have limited capacity to explain how availability of cheap, highly palatable, readily assimilated, energy-dense foods lead to obesity in modern environments. Neuropsychological constructs including food reward (liking, wanting and learning), reactive and reflective decision making, in the context of asymmetric energy balance regulation, give more comprehensive explanations of how environmental superabundance of foods containing mixtures of readily assimilated fats and carbohydrates and caloric beverages elevate EI through combined hedonic, affective, cognitive and physiological mechanisms. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Veganism and body weight: An N of 1 self-experiment

The causal effect that veganism has on body weight has not been scientifically examined. An N of 1 self-experiment was conducted in which blinded body weight and additional behavioural and psychological measures were assessed during two phases of vegan vs. non-vegan lifestyle adherence. In study phase 1, body weight change was -0.8 kg over 1 month of veganism (vs. +0.5 kg non-vegan month). In study phase 2, weight change was -1.2 kg over two veganism months (vs. +1.6 kg non-vegan months). Behavioural and psychological measures were similar during vegan vs. non-vegan periods. Veganism appeared to reduce body weight in this N of 1 self-experiment.

Effects of ketone bodies on energy expenditure, substrate utilization, and energy intake in humans

The potential of ketogenic approaches to regulate energy balance has recently gained attention since ketones may influence both energy expenditure and energy intake. In this narrative review, we summarized the most relevant evidence about the role of ketosis on energy expenditure, substrate utilization, and energy intake in humans. We considered different strategies to induce ketosis, such as fasting, dietary manipulation, and exogenous ketone sources. In general, ketosis does not have a major influence on energy expenditure but promotes a shift in substrate utilization towards ketone body oxidation. The strategies to induce ketosis by reduction of dietary carbohydrate availability (e.g., ketogenic diets) do not independently influence energy intake, being thus equally effective for weight loss as diets with higher carbohydrate content. In contrast, the intake of medium-chain triglycerides and ketone esters induces ketosis and appears to increase energy expenditure and reduce energy intake in the context of high carbohydrate availability. These latter strategies lead to slightly enhanced weight loss. Unfortunately, distinguishing the effects of the various ketogenic strategies per se from the effects of other physiological responses is not possible with the available human data. Highly controlled, inpatient studies using targeted strategies to isolate the independent effects of ketones are required to adequately address this knowledge gap.

Criterion validity of wrist accelerometry for assessing energy intake via the intake-balance technique

BACKGROUND

Intake-balance assessments measure energy intake (EI) by summing energy expenditure (EE) with concurrent change in energy storage (ΔES). Prior work has not examined the validity of such calculations when EE is estimated via open-source techniques for research-grade accelerometry devices. The purpose of this study was to test the criterion validity of accelerometry-based intake-balance methods for a wrist-worn ActiGraph device.

METHODS

Healthy adults (n = 24) completed two 14-day measurement periods while wearing an ActiGraph accelerometer on the non-dominant wrist. During each period, criterion values of EI were determined based on ΔES measured by dual X-ray absorptiometry and EE measured by doubly labeled water. A total of 11 prediction methods were tested, 8 derived from the accelerometer and 3 from non-accelerometry methods (e.g., diet recall; included for comparison). Group-level validity was assessed through mean bias, while individual-level validity was assessed through mean absolute error, mean absolute percentage error, and Bland-Altman analysis.

RESULTS

Mean bias for the three best accelerometry-based methods ranged from -167 to 124 kcal/day, versus -104 to 134 kcal/day for the non-accelerometry-based methods. The same three accelerometry-based methods had mean absolute error of 323-362 kcal/day and mean absolute percentage error of 18.1-19.3%, versus 353-464 kcal/day and 19.5-24.4% for the non-accelerometry-based methods. All 11 methods demonstrated systematic bias in the Bland-Altman analysis.

CONCLUSIONS

Accelerometry-based intake-balance methods have promise for advancing EI assessment, but ongoing refinement is necessary. We provide an R package to facilitate implementation and refinement of accelerometry-based methods in future research (see paulhibbing.com/IntakeBalance).

Metabolomic based approach to identify biomarkers of broccoli intake

It is well-established that consumption of cruciferous and brassica vegetables has a correlation with reduced rates of many negative health outcomes. There is an increased interest in identifying food intake biomarkers to address limitations related to self-reported dietary assessment. The study aims to identify biomarkers of broccoli intake using metabolomic approaches, examine the dose-response relationship, and predict the intake by multimarker panel. Eighteen volunteers consumed cooked broccoli in A-Diet Discovery study and fasting and postprandial urine samples were collected at 2, 4 and 24 hours. Subsequently the A-Diet Dose-response study was performed where volunteers consumed different portions of broccoli (49, 101 or 153 g) and urine samples were collected at the end of each intervention week. Urine samples were analysed by 1H-NMR and LC-MS. Multivariate data analysis and one-way ANOVA were performed to identify discriminating biomarkers. A panel of putative biomarkers was examined for its ability to predict intake through a multiMarker model. Multivariate analysis revealed discriminatory spectral regions between fasting and fed metabolic profiles. Subsequent time-series plots revealed multiple features increased in concentration following the consumption. Urinary S-methyl cysteine sulfoxide (SMCSO) increased as broccoli intake increased (0.17-0.24 μM per mOSM per kg, p < 0.001). Similarly from LC-MS data genipin, dihydro-β-tubaic acid and sinapic acid increased with increasing portions of intake. A panel of 8 features displayed good ability to predict intake from biomarker data only. In conclusion, urinary SMCSO and several LC-MS features appeared as potentially promising biomarkers of broccoli consumption and demonstrated dose-response relationship. Future work should focus on validating these compounds as food intake biomarkers.

The influence of physical activity on neural responses to visual food cues in humans: A systematic review of functional magnetic resonance imaging studies

This systematic review examined whether neural responses to visual food-cues measured by functional magnetic resonance imaging (fMRI) are influenced by physical activity. Seven databases were searched up to February 2023 for human studies evaluating visual food-cue reactivity using fMRI alongside an assessment of habitual physical activity or structured exercise exposure. Eight studies (1 exercise training, 4 acute crossover, 3 cross-sectional) were included in a qualitative synthesis. Structured acute and chronic exercise appear to lower food-cue reactivity in several brain regions, including the insula, hippocampus, orbitofrontal cortex (OFC), postcentral gyrus and putamen, particularly when viewing high-energy-density food cues. Exercise, at least acutely, may enhance appeal of low-energy-density food-cues. Cross-sectional studies show higher self-reported physical activity is associated with lower reactivity to food-cues particularly of high-energy-density in the insula, OFC, postcentral gyrus and precuneus. This review shows that physical activity may influence brain food-cue reactivity in motivational, emotional, and reward-related processing regions, possibly indicative of a hedonic appetite-suppressing effect. Conclusions should be drawn cautiously given considerable methodological variability exists across limited evidence.

Evaluating self-reported retrospective average daily fruit, vegetable, and egg intake: Trustworthy-Sometimes!

Retrospective self-reports are commonly used to assess dietary intake. Yet, their use is criticized as it is unclear whether the underlying assumptions for valid self-reports are met: Individuals have to consider the behavior of all days in the retention interval and weigh the behavior of all days equally. This study examines whether these assumptions for retrospective self-reports are met and whether interindividual differences in self-report performance are relevant regarding these assumptions. Ninety-two participants aged 18-61 years participated in seven sequential 24-h recalls and one retrospective 7-day recall concerning their intake of fruit, vegetables, and eggs. A multiple linear regression approach was used to examine the relation between the daily reported dietary intake and the 7-day recall. In the overall sample, the requirements for retrospective self-reports were not tenable. Distinguishing good and poor self-reporters based on a rational criterion showed that the requirements can be taken as given for good self-reporters, whereas poor self-reporters base their retrospective self-reports mostly on recency effects. The underlying requirements for retrospective self-reports appear to be met in two thirds of the sample, supporting the use of retrospective self-reports to capture dietary behavior. Future research should investigate characteristics separating good from poor self-reporters.

High- and normal-protein diets improve body composition and glucose control in adults with type 2 diabetes: a randomized trial

OBJECTIVE

Weight loss of ≥10% improves glucose control and may remit type 2 diabetes (T2D). High-protein (HP) diets are commonly used for weight loss, but whether protein sources, especially red meat, impact weight loss-induced T2D management is unknown. This trial compared an HP diet including beef and a normal-protein (NP) diet without red meat for weight loss, body composition changes, and glucose control in individuals with T2D.

METHODS

A total of 106 adults (80 female) with T2D consumed an HP (40% protein) diet with ≥4 weekly servings of lean beef or an NP (21% protein) diet excluding red meat during a 52-week weight loss intervention. Body weight, body composition, and cardiometabolic parameters were measured before and after intervention.

RESULTS

Weight loss was not different between the HP (-10.2 ± 1.6 kg) and NP (-12.7 ± 4.8 kg, p = 0.336) groups. Both groups reduced fat mass and increased fat-free mass percent. Hemoglobin A1c, glucose, insulin, insulin resistance, blood pressure, and triglycerides improved, with no differences between groups.

CONCLUSIONS

The lack of observed effects of dietary protein and red meat consumption on weight loss and improved cardiometabolic health suggests that achieved weight loss, rather than diet composition, should be the principal target of dietary interventions for T2D management.

Predicting energy intake with an accelerometer-based intake-balance method

Nutritional interventions often rely on subjective assessments of energy intake (EI), but these are susceptible to measurement error. To introduce an accelerometer-based intake-balance method for assessing EI using data from a time-restricted eating (TRE) trial. Nineteen participants with overweight/obesity (25-63 years old; 16 females) completed a 12-week intervention (NCT03129581) in a control group (unrestricted feeding; n 8) or TRE group (n 11). At the start and end of the intervention, body composition was assessed by dual-energy X-ray absorptiometry (DXA) and daily energy expenditure (EE) was assessed for 2 weeks via wrist-worn accelerometer. EI was back-calculated as the sum of net energy storage (from DXA) and EE (from accelerometer). Accelerometer-derived EI estimates were compared against estimates from the body weight planner of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Mean EI for the control group declined by 138 and 435 kJ/day for the accelerometer and NIDDK methods, respectively (both P ≥ 0·38), v. 1255 and 1469 kJ/day, respectively, for the TRE group (both P < 0·01). At follow-up, the accelerometer and NIDDK methods showed excellent group-level agreement (mean bias of -297 kJ/day across arms; standard error of estimate 1054 kJ/day) but high variability at the individual level (limits of agreement from -2414 to +1824 kJ/day). The accelerometer-based intake-balance method showed plausible sensitivity to change, and EI estimates were biologically and behaviourally plausible. The method may be a viable alternative to self-report EI measures. Future studies should assess criterion validity using doubly labelled water.

Habitual Physical Activity and Dietary Profiles in Older Japanese Males with Normal-Weight Obesity

Normal-weight obesity is defined as having high body fat but a normal body mass index (BMI). This study examined whether there are differences in habitual physical activity and diet between individuals with normal-weight obesity and obese or non-obesity. This study included 143 males aged 65-75 years, and they were classified into the following three groups according to BMI and visceral fat area (VFA): obese group (n = 27 (BMI: ≥25 kg/m² and VFA: ≥100 cm²)), normal-weight obese group (n = 35 (BMI: <25 kg/m² and VFA: ≥100 cm²)) and non-obese group (n = 81 (BMI: <25 kg/m² and VFA < 100 cm²)). Lowered high-density lipoprotein cholesterol and elevated triglyceride and alanine transaminase were observed in the normal-weight obese group than in the non-obese group (all for p ≤ 0.04, effect size ≥ 0.50). No differences were found in physical activity and dietary habits between non-obese and normal-weight obese groups (all for p > 0.05). Although impaired lipid and liver function parameters were observed in older males with normal-weight obesity compared with older males with non-obesity, physical activity and dietary profiles in themselves were not shown these differences in the present study.

Disentangling the effects of obesity and high-fat diet on glucose homeostasis using a photoperiod induced obesity model implicates ectopic fat deposition as a key factor

OBJECTIVE

Obesity in laboratory rodents is generally induced by feeding them a high fat diet (HFD). This model does not permit separation of the impact of the HFD from the resultant obesity on metabolic defects such as impaired glucose homeostasis. In Brandt's voles we have previously shown that exposure to long photoperiod (LD: 16L: 8D) induces obesity even when they are fed a low fat diet. We show here that these voles are largely resistant to HFD. This model therefore permits some separation of the effects of HFD and obesity on glucose homeostasis. The objective was therefore to use this model to assess if glucose homeostasis is more related to diet or obesity METHODS: Male voles, which were 35 days old and born in LD, were exposed to SD and a low fat diet for 70 days. We then randomly separated the animals into 4 groups for another 63 days: SL (short day and low fat diet: n = 19) group; SH (short day and high-fat diet, n = 20) group; LL (long day and low-fat diet, n = 20) group; LH (long day and high-fat diet, n = 18) group. Glucose tolerance tests (GTT) were performed after treatment for 56 days, and body compositions of the voles were quantified at the end by dissection.

RESULTS

Consistent with our previous work LD voles were more obese than SD voles. Although total body weight was independent of dietary fat content, HFD did have an effect on fat storage. Photoperiod induced obesity had no effect on glucose homeostasis, and the fat content in both the liver and muscle. In contrast, HFD induced adiposity was linked with elevated fat deposition in muscle (but not in liver) and led to impaired glucose tolerance.

CONCLUSIONS

The contrasting effects of diet and photoperiod were consistent with the predictions of the 'lipotoxicity hypothesis'. This may contribute to our understanding of why some human individuals are able to be obese yet remain metabolically healthy.

Equating NHANES Monitor-Based Physical Activity to Self-Reported Methods to Enhance Ongoing Surveillance Efforts

PURPOSE

Harmonization of assessment methods represents an ongoing challenge in physical activity research. Previous research has demonstrated the utility of calibration approaches to enhance agreement between measures of physical activity. The present study utilizes a calibration methodology to add behavioral context from the Global Physical Activity Questionnaire (GPAQ), an established report-based measure, to enhance interpretations of monitor-based data scored using the novel Monitor Independent Movement Summary (MIMS) methodology.

METHODS

Matching data from the GPAQ and MIMS were obtained from adults (20-80 yr of age) assessed in the 2011-2014 National Health and Nutrition Examination Survey. After developing percentile curves for self-reported activity, a zero-inflated quantile regression model was developed to link MIMS to estimates of moderate to vigorous physical activity (MVPA) from the GPAQ.

RESULTS

Cross-validation of the model showed that it closely approximated the probability of reporting MVPA across age and activity-level segments, supporting the accuracy of the zero-inflated model component. Validation of the quantile regression component directly corresponded to the 25%, 50%, and 75% values for both men and women, further supporting the model fit.

CONCLUSIONS

This study offers a method of improving activity surveillance by translating accelerometer signals into interpretable behavioral measures using nationally representative data. The model provides accurate estimates of minutes of MVPA at a population level but, because of the bias and error inherent in report-based measures of physical activity, is not suitable for converting or interpreting individual-level data. This study provides an important preliminary step in utilizing information from both device- and report-based methods to triangulate activity related outcomes; however additional measurement error modeling is needed to improve precision.

Validity of the Xiaomi Mi Band 2, 3, 4 and 5 Wristbands for Assessing Physical Activity in 12-to-18-Year-Old Adolescents under Unstructured Free-Living Conditions. Fit-Person Study

The purpose was to assess the validity of four generations of Xiaomi Mi Band wristbands for the assessment of step count and physical activity (PA) levels among adolescents aged 12-18 years under free-living conditions. One hundred adolescents were invited to participate in the present study. The final sample consisted of 62 high-school students (34 females), aged 12-18 years old (Mage = 14.1 ± 1.6 years), who wore an ActiGraph accelerometer on their hip (PA and step count reference measures) and four activity wristbands (Xiaomi Mi Band 2, 3, 4, and 5) on their non-dominant wrist during the waking time of one day. Results showed that the agreement between daily PA levels (i.e., slow, brisk, and slow-brisk pace walking, total PA and moderate-to-vigorous PA) measured by Xiaomi Mi Band wristbands and the accelerometer were poor (ICC, 95% CI = 0.06-0.78, 0.00-0.92; MAPE = 50.1-150.6%). However, agreement between daily step count measured by the accelerometer and the Xiaomi Mi Band wristbands were between acceptable (MAPE = 12.2-13.6%) to excellent (ICC, 95% CI = 0.94-0.95, 0.90-0.97). Furthermore, the Xiaomi Mi Band wristbands have a good to excellent validity for correctly classifying adolescents as meeting or not meeting the recommended 10,000 steps per day (P = 0.89-0.95, k = 0.71-0.87) and the recommended 60 minutes of moderate-to-vigorous PA per day (P = 0.89-0.94, k = 0.69-0.83). Furthermore, comparability between the four Xiaomi Mi Band generations were poor to excellent (ICC, 95% CI = 0.22-0.99, 0.00-1.00) for the daily PA levels outputs, although it was excellent (ICC, 95% CI = 0.99-1.00, 0.96-1.00; MAPE = 0.0-0.1%) for daily step count. Different models of Xiaomi Mi Band wristbands were comparable and presented good validity for measuring adolescents' step count, and they accurately classified adolescents as meeting or not meeting the PA recommendations under free-living conditions.

[Evaluation of a program led by community workers to promote cardiometabolic health in adults in a highly marginalized Mexican municipality]

OBJECTIVE

to evaluate the impact of a group program of nutrition education implemented by community workers on food consumption, physical activity and cardiometabolic risk.

MATERIAL AND METHODS

a randomized trial by conglomerates was performed. The intervention group (n = 246) participated in a program of nine group sessions of nutrition education delivered by community workers and focused on giving healthy habits options and evocation of motivations. The control group (n = 183) received printed information on healthy eating and physical activity. At the beginning of the study and after one year of follow-up, anthropometric measurements of blood pressure, heart rate, lipid profile and glucose were assessed. A questionnaire was applied to collect sociodemographic data, food consumption and physical activity.

RESULTS

in multilevel regression models it was observed that the intervention group reported an increase in the frequency of consumption of fruits, vegetables and legumes, increased body mass index and its probability of increasing recreational physical activity was higher; in addition, it reduced its consumption of sweetened cereals, and decreased the probability of hyperglycemia compared to the control group. Resting heart rate increased in both groups, but the increase was lower in the intervention group.

CONCLUSIONS

nutrition education guided by community workers can have positive effects on cardiometabolic risk, so it would be an alternative to traditional education focused on providing information.

Lack of compensation of energy intake explains the success of alternate day feeding to produce weight loss

BACKGROUND AND AIMS

This study was designed to obtain daily weighed food intake of participants engaged in Alternate Day Feeding (ADF). Prior ADF studies have used self-reported food intake, a method that has received criticism for its limited accuracy.

SUBJECTS AND METHODS

Forty-nine university students received academic credit for participating in the study. Following a 10-day baseline period, participants underwent ADF for the next 8 days. Restricted daily intake to ∼ 75% of baseline food intake levels was followed by ad libitum intake on alternate days. Food intake was weighed before and after each meal. Daily body weight was also tracked.

INTERVENTION

After the baseline period, participants underwent 8 days of ADF during which they consumed ∼ 75% of baseline energy intake by weight followed by ad libitum intake on alternate days. The trial concluded with 2 additional days of ad libitum feeding, for a total study duration of 10 days.

RESULTS

Daily food intake was constant during the baseline period (slope = -0.93 g/d, p = 0.56), and did not differ significantly (995 g (95% CI [752, 1198]) from the total consumed on ad libitum ADF days (951 g (95% CI [777, 1227]). Intake on ad libitum days did not show a trend to increase during the intervention. Body weight declined significantly during ADF.

CONCLUSIONS

ADF produces significant weight loss because food intake does not increase on ad libitum feeding days to compensate for reduced intake on restricted energy days. Data are consistent with prior work that suggests humans do not fully compensate for imposed deficits in energy intake.

Discordance between assessments of food cue responsiveness: Implications for assessment in youth with overweight/obesity

Food cue responsiveness (FCR), broadly defined as behavioral, cognitive, emotional and/or physiological responses to external appetitive cues outside of physiological need, contributes to overeating and obesity among youth and adults. A variety of measures purportedly assess this construct, ranging from youth- or parent-report surveys to objective eating tasks. However, little research has assessed their convergence. It is especially important to evaluate this in children with overweight/obesity (OW/OB), as reliable and valid assessments of FCR are essential to better understand the role of this critical mechanism in behavioral interventions. The present study examined the relationship between five measures of FCR in a sample of 111 children with OW/OB (mean age = 10.6, mean BMI percentile = 96.4; 70% female; 68% white; 23% Latinx). Assessments included: objectively measured eating in the absence of hunger (EAH), parasympathetic activity when exposed to food, parent reported food responsiveness subscale from the Child Eating Behavior Questionnaire (CEBQ-FR), child self-reported Power of Food total score (C-PFS), and child self-reported Food Cravings Questionnaire total score (FCQ-T). Statistically significant spearman correlations were found between EAH and CEBQ-FR (ρ = 0.19, p < 0.05) and parasympathetic reactivity to food cues with both C-PFS (ρ = -0.32, p = 0.002) and FCQ-T (ρ = -0.34, p < 0.001). No other associations were statistically significant. These relationships remained significant in subsequent linear regression models controlling for child age and gender. The lack of concordance between measures assessing highly conceptually related constructs is of concern. Future studies should seek to elucidate a clear operationalization of FCR, examine the associations between FCR assessments in children and adolescents with a range of weight statuses, and evaluate how to best revise these measures to accurately reflect the latent construct being assessed.

The impact of acute exercise on appetite control: Current insights and future perspectives

The interaction of exercise with appetite control and energy intake has been widely studied due to the ability of exercise-related energy expenditure to influence energy and substrate balance. Many empirical studies have explored appetite and energy intake responses to acute (single) exercise bouts involving a variety of protocols in diverse populations revealing several consistent trends. The balance of evidence suggests that acute moderate-to-vigorous intensity land-based exercise suppresses subjective appetite feelings and the orexigenic hormone acylated ghrelin and elevates the anorexigenic hormones peptide YY and glucagon-like peptide-1. These perturbations are transient and hormone concentrations usually return to resting values in the hours after exercise without evoking compensatory increases in appetite or energy intake on the same day. This evidence counters the popular assertion that exercise transiently increases appetite and may prompt greater energy intake at subsequent meals. The indifference of the appetite control system to acute exercise-induced energy deficits contrasts with the immediate increases in appetite and energy intake provoked by equivalent diet-induced energy deficits. There is, however, considerable inter-individual variability in subjective appetite and hormonal responses to acute exercise with some individuals experiencing greater exercise-induced appetite suppression than others. Current evidence supports the promotion of exercise as a strategy for inducing a short-term energy deficit but the relevance of this for long-term appetite regulation and the control of body mass remains uncertain.

Effectiveness of a Smartphone App (e-12HR) in Improving Adherence to the Mediterranean Diet in Spanish University Students by Age, Gender, Field of Study, and Body Mass Index: A Randomized Controlled Trial

There is an urgent need to implement intervention programs to promote adherence to the Mediterranean diet (AMD) in university students to prevent non-communicable diseases. A powerful tool for this is smartphone apps. Furthermore, it is necessary to determine the subgroups that are most likely to benefit from these technologies. The objective is to evaluate the effectiveness of an app (e-12HR) at improving AMD in a sample of Spanish university students and different strata. The study method was a controlled and randomized clinical trial over a four-week follow-up period and involving 385 participants (76.9% women). The participants were in two parallel groups: the control group (CG) and the intervention group (IG), with only the IG receiving feedback to improve their AMD. There were significant statistical improvements (with higher values in the IG) at week four, after no significant statistical differences at baseline (Week One): in the whole sample: +25.7% AMD index and +74.5% percentage with moderate/high AMD index. In the subgroups, seven of eight subgroups, ranging in AMD index from +17.8% (≥20 years) to +33.0% (<20 years); and for males, in weeks two (+27.9%) and three (+23.9%), but not at week four. In conclusion, e-12HR could improve AMD among university students (in the total sample and all subgroups, except ≥25 kg/m2).

Effect of ultra-processed food intake on metabolic syndrome components and body fat in children and adolescents: A systematic review based on cohort studies

OBJECTIVES

The aim of this study was to thoroughly review the scientific literature related to cohort studies that evaluated the association between the intake of ultra-processed foods, according to the NOVA classification, and the increase in the components of metabolic syndrome and body fat in children and adolescents.

METHODS

We consulted the PubMed, Scielo, Lilacs, and ScienceDirect databases and selected cohort studies that met the main objective of this review and included the age group of interest. We used an adaptation of the Newcastle-Ottawa scale to evaluate cohort studies.

RESULTS

Of 383 articles identified, 367 were excluded after reading the title, abstract, and methodology. Only nine met the selection criteria defined for this review. Of the nine articles, two reported a positive association between high consumption of ultra-processed foods and total cholesterol levels; one reported a positive association with low-density lipoprotein cholesterol, one with triacylglycerols, one with diastolic blood pressure, three with body mass index, two with waist circumference, and two with body fat.

CONCLUSIONS

Seven of nine studies found at least one association with components of metabolic syndrome. This highlights the importance of early intervention to prevent non-communicable diseases in the future.

Dietary Temperature's Influence on Energy Balance in Humans: Protocol for a Randomized Controlled Trial and Crossover Design

BACKGROUND

According to the first law of thermodynamics, energy cannot be created or destroyed in an isolated system. Water has a characteristically high heat capacity, indicating that the temperature of ingested fluids and meals could contribute to energy homeostasis. Citing the underlying molecular mechanisms, we present a novel hypothesis that states that the temperature of one's food and drink contributes to energy balance and plays a role in the development of obesity. We provide strong associations with certain molecular mechanisms that are activated by heat and correlate them with obesity and a hypothetical trial that could test this hypothesis. We conclude that if meal or drink temperature proves to contribute to energy homeostasis, then depending on its contribution and scale, future clinical trials should attempt to adjust this effect when analyzing data. In addition, previous research and established relationships of disease states with dietary patterns, energy intake, and food component intakes should be revisited. We understand the common assumption that thermal energy in food is absorbed by the body during digestion and dissipated as heat into the environment, not contributing to the energy balance. We challenge this assumption herein, including a proposed study design that would test our hypothesis.

OBJECTIVE

This paper hypothesizes that the temperature of ingested foods or fluids influences energy homeostasis through the expression of heat shock proteins (HSPs), especially HSP-70 and HSP-90, which are expressed to a greater extent in obesity and are known to cause deficits in glucose metabolism.

METHODS

We provide preliminary evidence supporting our hypothesis that greater dietary temperatures disproportionally induce activation of both intracellular and extracellular HSPs and that these HSPs influence energy balance and contribute to obesity.

RESULTS

This trial protocol has not been initiated and funding has not been sought at the time of this publication.

CONCLUSIONS

To date, no clinical trials are available regarding the potential effects of meal and fluid temperature on weight status or its confounding effects in data analysis. A potential mechanism is proposed as a basis by which higher temperatures of foods and beverages might influence energy balance via HSP expression. On the basis of the evidence supporting our hypothesis, we propose a clinical trial that will further elucidate these mechanisms.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/42846.

The exercise-induced suppression of acylated ghrelin is blunted in the luteal phase of the menstrual cycle compared to the follicular phase following vigorous-intensity exercise

Limited work examining woman's appetite-regulatory response to exercise has been focused on the follicular phase (FP) of the menstrual cycle. This is an important limitation as estradiol (E₂) and progesterone (P₄) fluctuate across phases with greater concentrations in the luteal phase (LP).

OBJECTIVE

To examine the appetite-regulatory response to vigorous-intensity continuous exercise (VICT) in the FP and LP.

METHODS

Twelve women completed 30 min of VICT at 80% V˙O_2max in the FP and LP. E₂, P₄, acylated ghrelin, active peptide tyrosine-tyrosine (PYY), active glucagon-like peptide-1 (GLP-1), and appetite perceptions were measured pre-exercise, 0-, 30-, and 90-min post-exercise. Energy intake was recorded for a 2-day period (day before and of each session). A series of two-way repeated measure ANOVA were used to compare all dependent variables.

RESULTS

Pre-exercise E₂ (P = 0.005, d = 1.00) and P₄ (P < 0.001, d = 1.41) concentrations were greater in the LP than the FP and exercise increased both at 0- and 30-min post-exercise (E₂: P < 0.009; P₄: P < 0.001, d = 0.63). Acylated ghrelin was lower in the FP versus LP at pre-exercise as well as 0-min (P = 0.006, d = 0.97) and 90-min (P = 0.029, d = 0.72) post-exercise. There were no differences of menstrual phase on PYY (P = 0.359, η_p² = 0.092), GLP-1 (P = 0.226, η_p² = 0.130), or overall appetite (P = 0.514, η_p² = 0.066). Energy intake was greater on the day of in the LP versus the FP (P = 0.003, d = 1.2).

CONCLUSION

Acylated ghrelin was lower in the FP compared to the LP and though there were no differences in anorexigenic hormones or subjective appetite, energy intake was greater on the day of the session in the LP suggesting important differences across the menstrual cycle where greater concentrations of ovarian hormones in the LP may blunt the exercise response.

Effects of Morning Vs. Evening exercise on appetite, energy intake, performance and metabolism, in lean males and females

Exercise is an important component of a weight management strategy. However, little is known about whether circadian variations in physiological and behavioural processes can influence the appetite and energy balance responses to exercise performed at different times of the day. This study compared the effects of morning and evening exercise on appetite, post-exercise energy intake, and voluntary performance. In randomised, counterbalanced order, 16 healthy males and females (n = 8 each) completed two trials, performing morning exercise at 10:30 (AMEx) or evening exercise at 18:30 (PMEx). Exercise consisted of 30 min steady-state cycling (60% V˙ O_2peak), and a 15-min performance test. A standardised meal (543 ± 86 kcal) was consumed 2-h before exercise and ad-libitum energy intake was assessed 15 min after exercise, with subjective appetite measured throughout. Absolute ad-libitum energy intake was 152 ± 126 kcal greater during PMEx (P < 0.001), but there was no differences in subjective appetite between trials immediately pre-exercise, or immediately before the post-exercise meal (P ≥ 0.060). Resting energy expenditure (P < 0.01) and carbohydrate oxidation (P < 0.05) were greater during AMEx, but there were no differences in substrate oxidation or energy expenditure during exercise (P ≥ 0.155). Exercise performance was not different between trials (P = 0.628). In conclusion, acute morning and evening exercise prompt similar appetite responses, but post-exercise ad-libitum energy intake is greater following evening exercise. These findings demonstrate discordant responses between subjective appetite and ad-libitum energy intake but suggest that exercise might offset circadian variations in appetite. Longer-term studies are required to determine how exercise timing affects adherence and weight management outcomes to exercise interventions. TRIAL REGISTRATION: NCT04742530, February 8, 2021.

Perspective: Is the Response of Human Energy Expenditure to Increased Physical Activity Additive or Constrained?

The idea that increasing physical activity directly adds to TEE in humans (additive model) has been challenged by the energy constrained hypothesis (constrained model). This model proposes that increased physical activity decreases other components of metabolism to constrain TEE. There is a logical evolutionary argument for trade-offs in metabolism, but, to date, evidence supporting constraint is subject to several limitations, including cross-sectional and correlational studies with potential methodological issues from extreme differences in body size/composition and lifestyle, potential statistical issues such as regression dilution and spurious correlations, and conclusions drawn from deductive inference rather than direct observation of compensation. Addressing these limitations in future studies, ideally, randomized controlled trials should improve the accuracy of models of human energy expenditure. The available evidence indicates that in many scenarios, the effect of increasing physical activity on TEE will be mostly additive although some energy appears to "go missing" and is currently unaccounted for. The degree of energy balance could moderate this effect even further. Adv Nutr 2023;x:xx-xx.

Contextual Specificity of (Un)Healthy Food/Drink Intake in Everyday Life: A Study Based on Episodic Memories

Identifying the contexts of episodes of (un)healthy food/drink intake could inform strategies for eating more healthily. This study assessed memories of recent episodes of healthy and unhealthy eating from adults in Mexico. For each (un)healthy eating episode participants recalled place, time of day, people present and food/drink intake. Categories were formed for the contextual features and foods/drinks that were reported, then the relative frequency of each category was tested between healthy and unhealthy eating episodes. Overall, there was a large set of categories of (un)healthy food/drink choices, and there were more healthy eating episodes with family at home and unhealthy eating episodes with friends out of home. However, as expected, a more specific context as well as food/drink intake was identified for each sort of recalled (un)healthy eating episode of the day. Additionally, eating out of home, later in the day and with people present were features related to higher estimated energy content across (un)healthy eating episodes. These findings support the assessment of self-reported memories of recent eating episodes to generate evidence that contribute to contexts that support healthy eating habits.

Validating dietary assessment tools with energy expenditure measurement methods: Is this accurate?

Having an accurate dietary assessment tool is a necessity for most nutritional studies. As a result, many validation studies have been carried out to assess the validity of commonly used dietary assessment tools. Since based on the energy balance equation, among individuals with a stable weight, Energy Intake (EI) is equal to Energy Expenditure (EE) and there are precise methods for measurement of EE (e.g. doubly labeled water method), numerous studies have used this technique for validating dietary assessment tools. If there was a discrepancy between measured EI and EE, the researchers have concluded that self-reported dietary assessment tools are not valid or participants misreport their dietary intakes. However, the calculation of EI with common dietary assessment tools such as food frequency questionnaires (FFQs), 24-hour dietary recalls, or weighed food records, is based on fixed factors that were introduced by Atwater and the accuracy of these factors are under question. Moreover, the amount of energy absorption, and utilization from a diet, depends on various factors and there are considerable interindividual differences in this regard, for example in gut microbiota composition. As a result, the EI which is calculated using dietary assessment tools is likely not representative of real metabolizable energy which is equal to EE in individuals with stable weight, thus validating dietary assessment tools with EE measurement methods may not be accurate. We aim to address this issue briefly and propose a feasible elucidation, albeit not a complete solution.

Do eating behavior traits predict energy intake and body mass index? A systematic review and meta-analysis

At present, it is unclear whether eating behavior traits (EBT) predict objectively measured short-term energy intake (EI) and longer-term energy balance as estimated by body mass index (BMI). This systematic review examined the impact of EBT on BMI and laboratory-based measures of EI in adults ( ≥ 18 years) in any BMI category, excluding self-report measures of EI. Articles were searched up until 28th October 2021 using MEDLINE, PsycINFO, EMBASE and Web of Science. Sixteen EBT were identified and the association between 10 EBT, EI and BMI were assessed using a random-effects meta-analysis. Other EBT outcomes were synthesized qualitatively. Risk of bias was assessed with the mixed methods appraisal tool. A total of 83 studies were included (mean BMI = 25.20 kg/m² , mean age = 27 years and mean sample size = 70). Study quality was rated moderately high overall, with some concerns in sampling strategy and statistical analyses. Susceptibility to hunger (n = 6) and binge eating (n = 7) were the strongest predictors of EI. Disinhibition (n = 8) was the strongest predictor of BMI. Overall, EBT may be useful as phenotypic markers of susceptibility to overconsume or develop obesity (PROSPERO: CRD42021288694).

Machine learning modeling practices to support the principles of AI and ethics in nutrition research

BACKGROUND

Nutrition research is relying more on artificial intelligence and machine learning models to understand, diagnose, predict, and explain data. While artificial intelligence and machine learning models provide powerful modeling tools, failure to use careful and well-thought-out modeling processes can lead to misleading conclusions and concerns surrounding ethics and bias.

METHODS

Based on our experience as reviewers and journal editors in nutrition and obesity, we identified the most frequently omitted best practices from statistical modeling and how these same practices extend to machine learning models. We next addressed areas required for implementation of machine learning that are not included in commercial software packages.

RESULTS

Here, we provide a tutorial on best artificial intelligence and machine learning modeling practices that can reduce potential ethical problems with a checklist and guiding principles to aid nutrition researchers in developing, evaluating, and implementing artificial intelligence and machine learning models in nutrition research.

CONCLUSION

The quality of AI/ML modeling in nutrition research requires iterative and tailored processes to mitigate against potential ethical problems or to predict conclusions that are free of bias.

Resting energy expenditure of a diverse group of South African men and women

BACKGROUND

In South Africa, overweight/obesity is a public health concern, disproportionally affecting Black females. A contributory role of a lower resting energy expenditure (REE) is suggested for African Americans. The present study assessed the REE of Black and White South African adults aiming to better understand the underlying predictors to overweight/obesity and transform this into locally appropriate recommendations.

METHODS

In 328 (63% female; 39% Black) healthy South African adults, REE was measured with indirect calorimetry and body composition with multifrequency bioelectrical impedance analysis. The REE was estimated with 30 sets of published equations. Black-White differences in REE, as measured and adjusted (analysis of covariance), were determined with quantile regression. Reliability/agreement of estimated (against measured) REE was determined with intra-class correlations (ICCs) and Bland-Altman analysis. A new equation was developed by median regression followed by preliminary validation.

RESULTS

Measured REE (adjusted for age along with fat-free mass [FFM], FFM index, FFM plus fat mass, FFM index plus fat mass index) in White subjects was significantly higher (p < 0.001) than in Black subjects for men and women alike, regardless of obesity class. None of the sets of estimation equations had good agreement with measured REE for Black, White, male and female subjects simultaneously. A new estimation equation, based on whole-body variables, had good reliability (ICC = 0.79) and agreement (mean difference: 27 kJ) and presents practical opportunities for groups at the local grass-roots level.

CONCLUSIONS

The REE in Black South African adults is lower than in White adults. Tailored REE equations may improve REE estimation of racially/ethnically diverse South African groups and contribute to improved obesity management.