Nutrition Therapy

Too Much Dietary Flexibility May Hinder, Not Help: Could More Specific Targets for Daily Food Intake Distribution Promote Glycemic Management among Youth with Type 1 Diabetes?

Average glycemic levels among youth with type 1 diabetes (T1D) have worsened in some parts of the world over the past decade despite simultaneous increased uptake of diabetes technology, thereby highlighting the persistent need to identify effective behavioral strategies to manage glycemia during this life stage. Nutrition is fundamental to T1D management. We reviewed the evidence base of eating strategies tested to date to improve glycemic levels among youth with T1D in order to identify promising directions for future research. No eating strategy tested among youth with T1D since the advent of flexible insulin regimens—including widely promoted carbohydrate counting and low glycemic index strategies—is robustly supported by the existing evidence base, which is characterized by few prospective studies, small study sample sizes, and lack of replication of results due to marked differences in study design or eating strategy tested. Further, focus on macronutrients or food groups without consideration of food intake distribution throughout the day or day-to-day consistency may partially underlie the lack of glycemic benefits observed in studies to date. Increased attention paid to these factors by future observational and experimental studies may facilitate identification of behavioral targets that increase glycemic predictability and management among youth with T1D.

Healthy food prescription incentive programme for adults with type 2 diabetes who are experiencing food insecurity: protocol for a randomised controlled trial, modelling and implementation studies

INTRODUCTION

The high cost of many healthy foods poses a challenge to maintaining optimal blood glucose levels for adults with type 2 diabetes mellitus who are experiencing food insecurity, leading to diabetes complications and excess acute care usage and costs. Healthy food prescription programmes may reduce food insecurity and support patients to improve their diet quality, prevent diabetes complications and avoid acute care use. We will use a type 2 hybrid-effectiveness design to examine the reach, effectiveness, adoption, implementation and maintenance (RE-AIM) of a healthy food prescription incentive programme for adults experiencing food insecurity and persistent hyperglycaemia. A randomised controlled trial (RCT) will investigate programme effectiveness via impact on glycosylated haemoglobin (primary outcome), food insecurity, diet quality and other clinical and patient-reported outcomes. A modelling study will estimate longer-term programme effectiveness in reducing diabetes-related complications, resource use and costs. An implementation study will examine all RE-AIM domains to understand determinants of effective implementation and reasons behind programme successes and failures.

METHODS AND ANALYSIS

594 adults who are experiencing food insecurity and persistent hyperglycaemia will be randomised to a healthy food prescription incentive (n=297) or a healthy food prescription comparison group (n=297). Both groups will receive a healthy food prescription. The incentive group will additionally receive a weekly incentive (CDN$10.50/household member) to purchase healthy foods in supermarkets for 6 months. Outcomes will be assessed at baseline and follow-up (6 months) in the RCT and analysed using mixed-effects regression. Longer-term outcomes will be modelled using the UK Prospective Diabetes Study outcomes simulation model-2. Implementation processes and outcomes will be continuously measured via quantitative and qualitative data.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the University of Calgary and the University of Alberta. Findings will be disseminated through reports, lay summaries, policy briefs, academic publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT04725630.

PROTOCOL VERSION

Version 1.1; February 2022.

Meal Replacements for Weight-Related Complications in Type 2 Diabetes: What Is the State of the Evidence?

Comprehensive lifestyle management is a fundamental aspect of diabetes care. Clinical practice guidelines for the nutritional management of diabetes have evolved considerably over the last 25 years shifting from a focus on single nutrients to food- and dietary pattern-based recommendations. Use of meal replacements as a temporary short-term strategy to induce weight loss and then transitioning to a healthier dietary pattern (e.g., Mediterranean or Portfolio) for weight loss maintenance fits well with this new shift in focus of clinical practice guidelines. As adherence is the most important determinant for attaining the benefits of any diet, health professionals should recommend evidence-based dietary patterns (including meal replacements) that align best with the patient's values, preferences, and treatment goals.

Novel trends and concepts in the nutritional management of glycemia in type 2 diabetes mellitus-beyond dietary patterns: a narrative review

A variety of eating patterns are recommended by international guidelines to help people with type 2 diabetes mellitus (T2DM) achieve general health and glycemia goals. Apart from eating patterns, there is evidence that other approaches related to the everyday application of dietary advice, such as meal frequency, breakfast consumption, daily carbohydrate distribution, and order of food consumption during meals, have significant effects on glycemia management. The aims of this review were to examine published diabetes nutrition guidelines concerning specific recommendations with regard to the above approaches, as well as to review evidence from studies that have investigated their effect on glycemia in T2DM. The data suggest that eating breakfast regularly, consuming most carbohydrates at lunch, avoiding large dinners late at night, and applying the carbohydrate-last meal pattern are effective practices towards better nutritional management of T2DM.

Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose-response meta-regression of prospective cohorts and randomized controlled trials

Nuts are recommended for cardiovascular health, yet concerns remain that nuts may contribute to weight gain due to their high energy density. A systematic review and meta-analysis of prospective cohorts and randomized controlled trials (RCTs) was conducted to update the evidence, provide a dose-response analysis, and assess differences in nut type, comparator and more in subgroup analyses. MEDLINE, EMBASE, and Cochrane were searched, along with manual searches. Data from eligible studies were pooled using meta-analysis methods. Interstudy heterogeneity was assessed (Cochran Q statistic) and quantified (I² statistic). Certainty of the evidence was assessed by Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Six prospective cohort studies (7 unique cohorts, n = 569,910) and 86 RCTs (114 comparisons, n = 5873) met eligibility criteria. Nuts were associated with lower incidence of overweight/obesity (RR 0.93 [95% CI 0.88 to 0.98] P < 0.001, "moderate" certainty of evidence) in prospective cohorts. RCTs presented no adverse effect of nuts on body weight (MD 0.09 kg, [95% CI -0.09 to 0.27 kg] P < 0.001, "high" certainty of evidence). Meta-regression showed that higher nut intake was associated with reductions in body weight and body fat. Current evidence demonstrates the concern that nut consumption contributes to increased adiposity appears unwarranted.

Strategically Playing with Fire: SGLT Inhibitors as Possible Adjunct to Closed-Loop Insulin Therapy

As closed-loop insulin therapies emerge into clinical practice and evolve in medical research for type 1 diabetes (T1D) treatment, the limitations in these therapies become more evident. These gaps include unachieved target levels of glycated hemoglobin in some patients, postprandial hyperglycemia, the ongoing need for carbohydrate counting, and the lack of non-glycemic benefits (such as prevention of metabolic syndrome and complications). Multiple adjunct therapies have been examined to improve closed-loop systems, yet none have become a staple. Sodium-glucose-linked cotransporter inhibitors (SGLTi's) have been extensively researched in T1D, with average reductions in placebo-adjusted HbA1c by 0.39%, and total daily dose by approximately 10%. Unfortunately, many trials revealed an increased risk of diabetic ketoacidosis, as high as 5 times the relative risk compared to placebo. This narrative review discusses the proven benefits and risks of SGLTi in patients with T1D with routine therapy, what has been studied thus far in closed-loop therapy in combination with SGLTi, the potential benefits of SGLTi use to closed-loop systems, and what is required going forward to improve the benefit to risk ratio in these insulin systems.

Glycemic Index Values of Pasta Products: An Overview

Durum wheat pasta is considered a low-glycemic index (GI) food. In recent years, the interest in developing enriched pasta has increased. Since both the formulation and processing technologies may affect the GI, this study aimed to investigate the GI values of pasta products (pp) reported in the literature until 2020. GI values of pp analyzed following the ISO guidelines were included in this survey. A total of 95 pp were identified and, according to their formulation, classified into 10 categories (n, mean GI): category n 1: 100% refined wheat (35, 55); category n 2: 100% whole wheat (6, 52); category n 3: other cereal-based products (8, 52); category n 4: containing egg (5, 52); category n 5: gluten free (11, 60); category n 6: containing legumes (9, 46); category n 7: noodles and vermicelli (9, 56); category n 8: containing vegetable or algae (6, 51); category n 9: containing other ingredients (5, 37); category n 10: stuffed (1, 58). Overall, pasta is confirmed to be a medium–low-GI food, even if a high variability among or within each category emerged. The formulation of enriched pp able to elicit a controlled glycemic response could represent a strategy to improve the nutritional value of pasta.

Dietary Glycaemic Index Labelling: A Global Perspective

The glycaemic index (GI) is a food metric that ranks the acute impact of available (digestible) carbohydrates on blood glucose. At present, few countries regulate the inclusion of GI on food labels even though the information may assist consumers to manage blood glucose levels. Australia and New Zealand regulate GI claims as nutrition content claims and also recognize the GI Foundation’s certified Low GI trademark as an endorsement. The GI Foundation of South Africa endorses foods with low, medium and high GI symbols. In Asia, Singapore’s Healthier Choice Symbol has specific provisions for low GI claims. Low GI claims are also permitted on food labels in India. In China, there are no national regulations specific to GI; however, voluntary claims are permitted. In the USA, GI claims are not specifically regulated but are permitted, as they are deemed to fall under general food-labelling provisions. In Canada and the European Union, GI claims are not legal under current food law. Inconsistences in food regulation around the world undermine consumer and health professional confidence and call for harmonization. Global provisions for GI claims/endorsements in food standard codes would be in the best interests of people with diabetes and those at risk.

Low-calorie sweeteners and human health: a rapid review of systematic reviews

INTRODUCTION

Low-calorie sweeteners are increasingly prevalent in the food supply and their consumption has increased in recent decades. Although low-calorie sweeteners approved for use are considered safe from a toxicological perspective, their short- and long-term impacts on chronic disease risk remain uncertain. The aim of this review was to summarize the evidence from systematic reviews on low-calorie sweetener use and chronic conditions and risk factors in children and adults.

METHODS

MEDLINE and the Cochrane Database of Systematic Reviews were searched to identify systematic reviews of randomized and nonrandomized studies that considered low-calorie sweeteners in relation to type 2 diabetes, cardiovascular disease, cancer, anthropometric measures, hypertension, hyperglycemia, hyperlipidemia, insulin resistance, and dental caries. Data were extracted from 9 reviews deemed of moderate or high quality on the basis of AMSTAR-2.

RESULTS

Narrative synthesis suggested inconsistent evidence on low-calorie sweetener use in relation to chronic conditions and associated risk factors, with nonrandomized studies suggesting positive associations and randomized studies suggesting negative or no associations.

CONCLUSION

Continued research on the long-term health impacts of low-calorie sweeteners across all life stages is warranted.

Low-volume walking HIIT: Efficient strategy to improve physical capacity and reduce the risk of cardiovascular disease in older women with type 2 diabetes

BACKGROUND AND AIMS

To compare the effect of a low-volume walking high-intensity interval training (HIIT) to moderate-intensity continuous training (MICT) on risk of cardiovascular diseases and physical capacity in older women with type 2 diabetes (T2D).

METHODS

Thirty inactive older women with T2D were randomized into either HIIT (75 min/week) or MICT (150 min/week). Cardiovascular risk profile (lipid profile; waist circumference and fat mass; resting, post-exercise and ambulatory blood pressure [BP]; VO₂ peak; UKPDS score; ABC's) and physical capacity were assessed before and after a 12-week intervention.

RESULTS

While resting systolic and diastolic BP (all p ≤ 0.01) were reduced, ambulatory BP (p ≥ 0.49) and lipid profile (p ≥ 0.40) remained unchanged after the intervention. Although VO₂ peak increased to a similar extent in both groups (p = 0.015), the distance covered during the 6MWT (p = 0.01) and grip strength (p = 0.02) increased to a greater extend in HIIT. The UKPDS risk score decreased in both groups after the intervention (p = 0.03) and 31% of the participants reached the ABC's compared to 24% at baseline.

CONCLUSION

Low-volume walking HIIT is an efficient exercise intervention for older women with T2D as it improved some CVD risk factors and physical capacity. Nevertheless, neither low-volume HIIT nor MICT is sufficient to affect ambulatory blood pressure in T2D patients.

Coffee consumption and cardiovascular diseases and mortality in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of cohort studies

AIMS

To evaluate the long-term consequences of coffee drinking in patients with type 2 diabetes.

DATA SYNTHESIS

PubMed, Scopus, and Web of Sciences were searched to November 2020 for prospective cohort studies evaluating the association of coffee drinking with risk of cardiovascular disease (CVD) and mortality in patients with type 2 diabetes. Two reviewers extracted data and rated the certainty of evidence using GRADE approach. Random-effects models were used to estimate the hazard ratios (HRs) and 95% CIs. Dose-response associations were modeled by a one-stage mixed-effects meta-analysis. Ten prospective cohort studies with 82,270 cases were included. Compared to those with no coffee consumption, the HRs for consumption of 4 cups/d were 0.79 (95%CI: 0.72, 0.87; n = 10 studies) for all-cause mortality, 0.60 (95%CI: 0.46, 0.79; n = 4) for CVD mortality, 0.68 (95%CI: 0.51, 0.91; n = 3) for coronary heart disease (CHD) mortality, 0.72 (95%CI: 0.54, 0.98; n = 2) for CHD, and 0.77 (95%CI: 0.61, 0.98; n = 2) for total CVD events. There was no significant association for cancer mortality and stroke. There was an inverse monotonic association between coffee drinking and all-cause and CVD mortality, and inverse linear association for CHD and total CVD events. The certainty of evidence was graded moderate for all-cause mortality, and low or very low for other outcomes.

CONCLUSIONS

Drinking coffee may be inversely associated with the risk of mortality in patients with type 2 diabetes. However, more research is needed considering type of coffee, sugar and cream added to coffee, and history of CVD to present more confident results.

REGISTRY AND REGISTRY NUMBER

The protocol of this systematic review was registered at Open Science Framework (https://osf.io/8uaf3, registered form: osf.io/xur76, registration DOI: 10.17605/OSF.IO/8UAF3).

Development of a Portfolio Diet Score and Its Concurrent and Predictive Validity Assessed by a Food Frequency Questionnaire

The Portfolio Diet, a plant-based portfolio of cholesterol-lowering foods, has been shown to reduce low-density lipoprotein cholesterol (LDL-C), and other cardiovascular risk factors, in randomized controlled trials (RCTs). It is not known if these beneficial effects translate to a lower incidence OF cardiovascular disease (CVD). To support examinations between Portfolio Diet adherence and disease, a Portfolio Diet score (PDS) was developed and its predictive and concurrent validity was assessed within the Toronto Healthy Diet Study, a six-month RCT in overweight adults. Predictive validity was assessed using change in the PDS measured by food frequency questionnaire (FFQ) and concomitant change in LDL-C from baseline to six months using multiple linear regression, adjusted for potential confounders (n = 652). Concurrent validity was assessed in a subset of participants (n = 50) who completed the FFQ and a 7-day diet record (7DDR) at baseline. The PDS determined from each diet assessment method was used to derive correlation coefficients and Bland–Altman plots to assess the between-method agreement. The change in PDS was inversely associated with change in LDL-C (β coefficients: −0.01 mmol/L (95% confidence intervals (CIs): −0.02, −0.002; p = 0.02). The correlation between the PDS from the FFQ and 7DDR was 0.69 (95% CIs: 0.48, 0.85). The Bland–Altman plot showed reasonable agreement between the score from the FFQ and 7DDR. These findings indicate predictive validity of the PDS with lower LDL-C, and reasonable concurrent validity of the PDS as assessed by an FFQ against a 7DDR.

Nutrition in Patients with Type 2 Diabetes: Present Knowledge and Remaining Challenges

Unhealthy behaviours, including diet and physical activity, coupled with genetic predisposition, drive type 2 diabetes (T2D) occurrence and severity; the present review aims to summarise the most recent nutritional approaches in T2D, outlining unmet needs. Guidelines consistently suggest reducing energy intake to counteract the obesity epidemic, frequently resulting in sarcopenic obesity, a condition associated with poorer metabolic control and cardiovascular disease. Various dietary approaches have been proposed with largely similar results, with a preference for the Mediterranean diet and the best practice being the diet that patients feel confident of maintaining in the long term based on individual preferences. Patient adherence is indeed the pivotal factor for weight loss and long-term maintenance, requiring intensive lifestyle intervention. The consumption of nutritional supplements continues to increase even if international societies do not support their systematic use. Inositols and vitamin D supplementation, as well as micronutrients (zinc, chromium, magnesium) and pre/probiotics, result in modest improvement in insulin sensitivity, but their use is not systematically suggested. To reach the desired goals, patients should be actively involved in the collaborative development of a personalised meal plan associated with habitual physical activity, aiming at normal body weight and metabolic control.

Effect of low glycaemic index or load dietary patterns on glycaemic control and cardiometabolic risk factors in diabetes: systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To inform the update of the European Association for the Study of Diabetes clinical practice guidelines for nutrition therapy.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Medline, Embase, and the Cochrane Library searched up to 13 May 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials of three or more weeks investigating the effect of diets with low glycaemic index (GI)/glycaemic load (GL) in diabetes.

OUTCOME AND MEASURES

The primary outcome was glycated haemoglobin (HbA1c). Secondary outcomes included other markers of glycaemic control (fasting glucose, fasting insulin); blood lipids (low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), non-HDL-C, apo B, triglycerides); adiposity (body weight, BMI (body mass index), waist circumference), blood pressure (systolic blood pressure (SBP) and diastolic blood pressure (DBP)), and inflammation (C reactive protein (CRP)).

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and assessed risk of bias. Data were pooled by random effects models. GRADE (grading of recommendations assessment, development, and evaluation) was used to assess the certainty of evidence.

RESULTS

29 trial comparisons were identified in 1617 participants with type 1 and 2 diabetes who were predominantly middle aged, overweight, or obese with moderately controlled type 2 diabetes treated by hyperglycaemia drugs or insulin. Low GI/GL dietary patterns reduced HbA1c in comparison with higher GI/GL control diets (mean difference −0.31% (95% confidence interval −0.42 to −0.19%), P<0.001; substantial heterogeneity, I2=75%, P<0.001). Reductions occurred also in fasting glucose, LDL-C, non-HDL-C, apo B, triglycerides, body weight, BMI, systolic blood pressure (dose-response), and CRP (P<0.05), but not blood insulin, HDL-C, waist circumference, or diastolic blood pressure. A positive dose-response gradient was seen for the difference in GL and HbA1c and for absolute dietary GI and SBP (P<0.05). The certainty of evidence was high for the reduction in HbA1c and moderate for most secondary outcomes, with downgrades due mainly to imprecision.

CONCLUSIONS

This synthesis suggests that low GI/GL dietary patterns result in small important improvements in established targets of glycaemic control, blood lipids, adiposity, blood pressure, and inflammation beyond concurrent treatment with hyperglycaemia drugs or insulin, predominantly in adults with moderately controlled type 1 and type 2 diabetes. The available evidence provides a good indication of the likely benefit in this population.

STUDY REGISTRATION

ClinicalTrials.gov NCT04045938.

Contextually Appropriate Tools and Solutions to Facilitate Healthy Eating Identified by People with Type 2 Diabetes

Type 2 diabetes (T2D) is a complex, multifaceted disease and its treatment involves lifestyle intervention (LI) programs that participants may find difficult to adopt and maintain. The objective of this study is to understand the lived experiences of participants with T2D regarding healthy eating behavior change, in order to identify and incorporate relevant information, skills, and educational approaches into LI programs. An explorative qualitative study was undertaken. Purposeful sampling was used to recruit 15 participants. One-on-one, semi-structured, open-ended, and in-depth interviews were conducted. An essentialist paradigm was adopted to accurately report the experiences, meaning, and reality of participants. An inductive approach was used to analyze the data. Participants reported that being diagnosed and living with T2D could be overwhelming, and their ability to manage was influenced by health care providers (HCP), family, and individual context. Many experienced a loop of “good–bad” eating behaviors. Participants expressed desires for future diabetes management that would include program content (nutrition, physical activity, mental health, foot care, and consequences of T2D), program features (understand context, explicit information, individualized, hands-on learning, applicable, realistic, incremental, and practical), program components (access to multidisciplinary team, set goals, track progress and be held accountable, one-on-one sessions, group support, maintenance/follow-up), and policy change. In conclusion, the results of this study indicate that T2D management requires more extensive, comprehensive, and ongoing support, guided by the individual participant.

Perspective: Plant-Based Eating Pattern for Type 2 Diabetes Prevention and Treatment: Efficacy, Mechanisms, and Practical Considerations

A plant-based eating pattern is associated with a reduced risk of developing type 2 diabetes and is highly effective in its treatment. Diets that emphasize whole grains, vegetables, fruits, and legumes and exclude animal products improve blood glucose concentrations, body weight, plasma lipid concentrations, and blood pressure and play an important role in reducing the risk of cardiovascular and microvascular complications. This article reviews scientific evidence on the effects of plant-based diets for the prevention and treatment of type 2 diabetes. The mechanisms by which plant-based diets improve body weight, insulin sensitivity, and β-cell function are described. Practical considerations including education, nutrition adequacy, and adjusting medications will enhance the success of patients who have diabetes.

Exercise-nutrient interactions for improved postprandial glycemic control and insulin sensitivity

Type 2 diabetes (T2D) is a rapidly growing yet largely preventable chronic disease. Exaggerated increases in blood glucose concentration following meals is a primary contributor to many long-term complications of the disease that decrease quality of life and reduce lifespan. Adverse health consequences also manifest years prior to the development of T2D due to underlying insulin resistance and exaggerated postprandial concentrations of the glucose-lowering hormone insulin. Postprandial hyperglycemic and hyperinsulinemic excursions can be improved by exercise, which contributes to the well-established benefits of physical activity for the prevention and treatment of T2D. The aim of this review is to describe the postprandial dysmetabolism that occurs in individuals at risk for and with T2D, and highlight how acute and chronic exercise can lower postprandial glucose and insulin excursions. In addition to describing the effects of traditional moderate-intensity continuous exercise on glycemic control, we highlight other forms of activity including low-intensity walking, high-intensity interval exercise, and resistance training. In an effort to improve knowledge translation and implementation of exercise for maximal glycemic benefits, we also describe how timing of exercise around meals and post-exercise nutrition can modify acute and chronic effects of exercise on glycemic control and insulin sensitivity. Novelty: Exaggerated postprandial blood glucose and insulin excursions are associated with disease risk. Both a single session and repeated sessions of exercise improve postprandial glycemic control in individuals with and without T2D. The glycemic benefits of exercise can be enhanced by considering the timing and macronutrient composition of meals around exercise.

Nutrition education on obesity and diabetes to medical students

It is important for medical students to understand the relationship between nutrition, obesity, and diabetes to educate their patients in the future. However, medical training does not always include nutritional education. An experiential learning project was incorporated into the medical school curriculum as an effort to implement nutrition in the physiology course. First-year medical students (n = 140) received lectures on the regulation of blood glucose levels and their relationship to carbohydrates with different glycemic indexes (GI), obesity, and diabetes. Lectures were followed by a laboratory exercise where students calculated their body mass index (BMI), percentage body fat, and percentage muscle using a Bioelectrical Impedance Commercial Scale. While 63% of students had normal BMI, 31% were overweight or obese and 5% were underweight. A subgroup of 54 students tested different types of breakfasts with varying GI and provided blood samples at 0, 30, 60, 90, and 120 min. Their glucose responses were plotted based on the breakfast GI. Pre- and posttests were conducted to assess the teaching intervention where the Wilcoxon signed ranks test indicated that posttest ranks were significantly higher than pretest ranks (Z = -6.6, P < 0.001), suggesting the intervention was beneficial to students.

Longitudinal changes in adherence to the portfolio and DASH dietary patterns and cardiometabolic risk factors in the PREDIMED-Plus study

BACKGROUND & AIMS

The Portfolio and Dietary Approaches to Stop Hypertension (DASH) diets have been shown to lower cardiometabolic risk factors in randomized controlled trials (RCTs). However, the Portfolio diet has only been assessed in RCTs of hyperlipidemic patients. Therefore, to assess the Portfolio diet in a population with metabolic syndrome (MetS), we conducted a longitudinal analysis of one-year data of changes in the Portfolio and DASH diet scores and their association with cardiometabolic risk factors in Prevención con Dieta Mediterránea (PREDIMED)-Plus trial.

METHODS

PREDIMED-Plus is an ongoing clinical trial (Trial registration: ISRCTN89898) conducted in Spain that includes 6874 older participants (mean age 65 y, 48% women) with overweight/obesity fulfilling at least three criteria for MetS. Data for this analysis were collected at baseline, six months and one year. Adherence to the Portfolio and DASH diet scores were derived from a validated 143-item food frequency questionnaire. We used linear mixed models to examine the associations of 1-SD increase and quartile changes in the diet scores with concomitant changes in cardiometabolic risk factors.

RESULTS

After adjusting for several potential confounders, a 1-SD increase in the Portfolio diet score was significantly associated with lower HbA1c (β [95% CI]: -0.02% [-0.02, -0.01], P < 0.001), fasting glucose (-0.47 mg/dL [-0.83, -0.11], P = 0.01), triglycerides (-1.29 mg/dL [-2.31, -0.28], P = 0.01), waist circumference (WC) (-0.51 cm [-0.59, -0.43], P < 0.001), and body mass index (BMI) (-0.17 kg/m² [-0.19, -0.15], P < 0.001). A 1-SD increase in the DASH diet score was significantly associated with lower HbA1c (-0.03% [-0.04, -0.02], P < 0.001), glucose (-0.84 mg/dL [-1.18, -0.51], P < 0.001), triglycerides (-3.38 mg/dL [-4.37, -2.38], P < 0.001), non-HDL-cholesterol (-0.47 mg/dL [-0.91, -0.04], P = 0.03), WC (-0.69 cm [-0.76, -0.60 cm], P < 0.001), BMI (-0.25 kg/m² [-0.28, -0.26 kg/m²], P < 0.001), systolic blood pressure (-0.57 mmHg [-0.81, -0.32 mmHg], P < 0.001), diastolic blood pressure (-0.15 mmHg [-0.29, -0.01 mmHg], P = 0.03), and with higher HDL-cholesterol (0.21 mg/dL [0.09, 0.34 mg/dL, P = 0.001]). Similar associations were seen when both diet scores were assessed as quartiles, comparing extreme categories of adherence.

CONCLUSIONS

Among older adults at high cardiovascular risk with MetS, greater adherence to the Portfolio and DASH diets showed significant favourable prospective associations with several clinically relevant cardiometabolic risk factors. Both diets are likely beneficial for cardiometabolic risk reduction.

The importance of glycemic index on post-prandial glycaemia in the context of mixed meals: A randomized controlled trial on pasta and rice

BACKGROUND AND AIMS

Post-prandial glycemic response (PPGR) depends on the intrinsic characteristic of the carbohydrate-rich foods as well as on the amount and type of other nutrients. This study aimed to explore whether the addition of condiments can affect the difference in PPGR between a low and a medium-high Glycemic Index (GI) food.

METHODS AND RESULTS

Spaghetti (S) and rice ® were consumed plain and after adding tomato sauce and extra virgin olive oil (TEVOO), or pesto sauce (P). The GI of R (63 ± 3) was statistically higher than that of S (44 ± 7) (p = 0.003). The Incremental Area Under the Curve (IAUC) for R was significantly greater than S (124.2 ± 12.1 and 82.1 ± 12.9 mmol∗min/L respectively) (p = 0.016) for blood glucose but not for insulin (1192.6 ± 183.6 and 905.2 ± 208.9 mU∗min/L, respectively) (p = 0.076). There were no significant differences after the addition of either TEVOO or P. The postprandial peaks of blood glucose and insulin for R (6.7 ± 0.3 mmol/L and 36.4 ± 4.9 mU/L, respectively) were significantly higher compared to S (6.0 ± 0.2 mmol/L and 26.7 ± 3.6 mU/L, respectively) (p = 0.033 and p = 0.025). The postprandial peak for insulin remained significantly higher with P (36.8 ± 3.7 and 28.6 ± 2.9 mU/L for R + P and S + P, p = 0.045) but not with EVOO (p = 0.963). Postprandial peaks for blood glucose were not significantly different with condiment.

CONCLUSIONS

The differences in PPGR were significant between spaghetti and rice consumed plain, they reduced or disappeared with fat adding, depending on the type of condiment used. REGISTRATION NUMBER: (www.clinicaltrial.gov):NCT03104712.

Low-carbohydrate diets and cardiometabolic health: the importance of carbohydrate quality over quantity

Carbohydrates are increasingly being implicated in the epidemics of obesity, diabetes, and their downstream cardiometabolic diseases. The "carbohydrate-insulin model" has been proposed to explain this role of carbohydrates. It posits that a high intake of carbohydrate induces endocrine deregulation marked by hyperinsulinemia, leading to energy partitioning with increased storage of energy in adipose tissue resulting in adaptive increases in food intake and decreases in energy expenditure. Whether all carbohydrate foods under real-world feeding conditions directly contribute to weight gain and its complications or whether this model can explain these clinical phenomena requires close inspection. The aim of this review is to assess the evidence for the role of carbohydrate quantity vs quality in cardiometabolic health. Although the clinical investigations of the "carbohydrate-insulin model" have shown the requisite decreases in insulin secretion and increases in fat oxidation, there has been a failure to achieve the expected fat loss under low-carbohydrate feeding. Systematic reviews with pairwise and network meta-analyses of the best available evidence have failed to show the superiority of low-carbohydrate diets on long-term clinical weight loss outcomes or that all sources of carbohydrate behave equally. High-carbohydrate diets that emphasize foods containing important nutrients and substances, including high-quality carbohydrate such as whole grains (especially oats and barley), pulses, or fruit; low glycemic index and load; or high fiber (especially viscous fiber sources) decrease intermediate cardiometabolic risk factors in randomized trials and are associated with weight loss and decreased incidence of diabetes, cardiovascular disease, and cardiovascular mortality in prospective cohort studies. The evidence for sugars as a marker of carbohydrate quality appears to be highly dependent on energy control (comparator) and food source (matrix), with sugar-sweetened beverages providing excess energy showing evidence of harm, and with high-quality carbohydrate food sources containing sugars such as fruit, 100% fruit juice, yogurt, and breakfast cereals showing evidence of benefit in energy-matched substitutions for refined starches (low-quality carbohydrate food sources). These data reflect the current shift in dietary guidance that allows for flexibility in the proportion of macronutrients (including carbohydrates) in the diet, with a focus on quality over quantity and dietary patterns over single nutrients.

Glenn A, M. S. Wolever T, G. Josse R, L. O’Connor D, Thompson A, D. Noseworthy R, Seider M, Sobie M, Bhatti G, Cavanagh J, Jones E, B. Darling P. Evaluation of Glycemic Index Education in People Living with Type 2 Diabetes: Participant Satisfaction, Knowledge Uptake, and Application

The glycemic index (GI) has been included in the Canadian clinical practice guidelines for type 2 diabetes (T2D) management since 2003, and even longer in other parts of the world (e.g., Australia). Despite this, dietitians have reported that GI is "too difficult for patients to understand and apply." They have called for diverse GI-utility data and evidence-informed education materials. To address these concerns, we developed and evaluated a GI education workshop and supporting materials, using the Kirkpatrick Model, for a T2D population. Participants (n = 29) with T2D attended a dietitian-facilitated workshop and received education materials. A mixed-form questionnaire (GIQ) and 3-day-diet-record were used to capture patient demographics, satisfaction, knowledge, and application, prior to and immediately after the workshop, 1-week, and 4-weeks post-education. Dietary GI was significantly lower at 1 and 4 weeks post-education (mean ± SEM; both 54 ± 1), compared to pre-education (58 ± 1; p ≤ 0.001). Participants (28/29) were satisfied with the intervention. The GI knowledge score was significantly higher post-education at baseline (83.5 ± 3.4%; p ≤ 0.001), week one (87.5 ± 2.6%; p = 0.035), and week four (87.6 ± 3.8%; p = 0.011) when compared to pre-education (53.6 ± 5.1%). A significant reduction in dietary GI was achieved by participants living with T2D, after completing the workshop, and they were able to acquire and apply GI knowledge in a relatively short period.

Destigmatizing Carbohydrate with Food Labeling: The Use of Non-Mandatory Labelling to Highlight Quality Carbohydrate Foods

Dietary carbohydrates are components of healthy foods, but many carbohydrate foods have recently been stigmatized as primary causes of diet-related risk factors for chronic disease. There is an opportunity to enhance efforts within the food landscape to encourage the consumption of higher quality carbohydrate foods. The use of labelling is one strategy that permits consumers to identify healthy carbohydrate foods at the point-of-purchase. This review discusses the regulatory frameworks and examples of associated non-mandatory food labelling claims that are currently employed to highlight healthy carbohydrate foods to consumers. The existing labelling frameworks discussed here align with established measures of carbohydrate quality, such as 1. dietary fibre nutrient content claims and associated dietary fibre-based health claims; 2. the presence of whole carbohydrate foods and ingredients that are intact or reconstituted, such as whole grains; and 3. low glycemic index and glycemic response claims. Standards from Codex Alimentarius, and regulations from Australia and New Zealand, Canada, Europe, and the United States will be used to illustrate the means by which food labelling can be used by consumers to identify quality carbohydrate foods.

A Mixed Methods Evaluation of a Randomized Control Trial to Evaluate the Effectiveness of the Pure Prairie Living Program in Type 2 Diabetes Participants

The primary objective of this randomized control trial was to evaluate the effectiveness of the Pure Prairie Living Program (PPLP) in a primary care setting. Adults with type 2 diabetes were randomized into intervention (PPLP, n = 25) and wait-listed controls (CON, n = 24). The PPLP group participated in education sessions. The intervention yielded no significant within-group changes in HbA1c at three-month (−0.04 (−0.27 to 0.17) and −0.15 (−0.38 to 0.08)) or six-month (−0.09 (−0.41 to 0.22) and 0.06 (−0.26 to 0.38)) follow ups in either CON or PPLP groups, respectively. Dietary adherence scores improved in the PPLP group (p < 0.05) at three and six months but were not different in the between-group comparison. No changes in diabetes self-efficacy scores were detected. In the qualitative analysis, participants described the program as clear and easy to understand. Knowledge acquired influenced their everyday decision making but participants faced barriers that prevented them from fully applying what they learned. Healthcare professionals enjoyed delivering the program but described the “back-stage” workload as detrimental. In conclusion, while some positive effects of the PPLP intervention were observed, they were not comparable to those previously attained by our group in an academic setting or to what the guidelines recommend, which reflects the challenge of translating lifestyle intervention to real-world settings.

Does Exercise Timing Affect 24-Hour Glucose Concentrations in Adults With Type 2 Diabetes? A Follow Up to the Exercise-Physical Activity and Diabetes Glucose Monitoring Study

OBJECTIVES

It is well known that exercise can improve the glycemic profile in individuals with type 2 diabetes (T2D). However, the optimal timing of exercise is often debated. Our aim in this study was to compare the effects of exercise performed at different times of the day and different timing in relation to meals on 24-hour glucose profiles in people with T2D.

METHODS

Fourteen individuals with T2D were recruited and wore continuous glucose monitors for 12 days. During the 12 days, participants completed 4 conditions according to a randomized, crossover design: i) morning (fasting) exercise (MorEx), ii) afternoon exercise (AftEx), iii) evening exercise (EveEx) and iv) seated control. Exercise consisted of 50 minutes of walking at 5.0 km/h.

RESULTS

Eight men and 6 women (age, 65±9.0 years; T2D duration, 10.5±6.8 years; mean glycated hemoglobin, 6.7±0.6%) were included in the analysis. Mean 24-hour continuously monitored glucose was 7.4±0.7 mmol/L, 7.3±0.7 mmol/L, 7.5±0.8 mmol/L and 7.5±0.7 mmol/L in the MorEx, AftEx, EveEx and control conditions, respectively, with no significant differences among the 4 conditions (p=0.55). MorEx had a lower respiratory exchange ratio compared with AftEx and EveEx (p<0.01). The decrease in glucose during exercise was less pronounced for MorEx compared with AftEx (p<0.05).

CONCLUSIONS

Fifty minutes of walking at 3 different times of day and at different timing in relation to meals did not lower 24-hour glucose concentrations in people with T2D. The reasons why exercise was not effective at lowering glucose remain unclear.

Effect of viscous fiber supplementation on obesity indicators in individuals consuming calorie-restricted diets: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Dietary fiber has played a consistent role in weight management, with efficacy potentially attributed to increased viscous fiber consumption.

PURPOSE

To summarize the effects of viscous fiber on body weight and other anthropometric parameters, along with a calorie-deficient diet, through a systematic review and meta-analysis.

METHODS

MEDLINE, EMBASE, and the Cochrane library were searched through July 24, 2019 for randomized controlled trials that assessed the effect of viscous fiber supplementation as part of a restricted calorie diet for ≥ 4 weeks relative to comparator diets. Data were pooled using the generic inverse-variance method with random-effects models and expressed as mean differences with 95% confidence intervals. Inter-study heterogeneity was assessed using Cochran's Q and quantified with I². The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the overall certainty of evidence.

RESULTS

Findings from 15 studies (n = 1347) showed viscous fiber supplementation significantly decreased body weight (- 0.81 kg [- 1.20, - 0.41]; p < 0.0001), BMI (- 0.25 kg/m² [- 0.46, - 0.05]; p = 0.01), and body fat (- 1.39% [- 2.61, - 0.17]; p = 0.03), compared to control. No effect on waist circumference was found. The certainty of evidence was graded as "moderate" for body weight, BMI, and body fat based on downgrades for imprecision. Waist circumference was graded "low" for downgrades of inconsistency and imprecision.

CONCLUSION

Viscous fiber within a calorie-restricted diet significantly improved body weight and other markers of adiposity in overweight adults and those with additional risk factors for cardiovascular disease. This trial is registered at www.clinicaltrials.gov as NCT03257449.

REGISTRATION

ClinicalTrials.gov identifier: NCT03257449.

Proximate Analysis and Nutritional Evaluation of Twenty Canadian Lentils by Principal Component and Cluster Analyses

Proximate composition and starch nutritional properties of twenty cooked lentils were assessed to identify unique varieties that could be used in value added foods. Significant variations exist among the lentil varieties (p < 0.05) with respect to their energy, fat, protein, carbohydrate, and dietary fiber content, and these are related to lentil type and seed size. Dazil and Greenstar were unique for their high resistant starch content (RS) and lower area under the starch hydrolysis curve (SHAUC) while Proclaim was opposite. SHAUC was positively correlated (p < 0.001) with rapidly digestible starch (RDS) content (r = 0.626) but negatively correlated with RS content (r = −0.635). Principal component analysis showed that the first three principal components accounted for 62.8% of the total variance and the contribution of SHAUC was 33.2%. These results confirm that in vitro SHAUC and a combination of RDS and RS may be predictive of the digestibility profile of cooked lentils.

The Role of Dietary Carbohydrates in Gestational Diabetes

Gestational diabetes (GDM) is hyperglycemia that is recognized for the first time during pregnancy. GDM is associated with a wide range of short- and long-term adverse health consequences for both mother and offspring. It is a complex disease with a multifactorial etiology, with disturbances in glucose, lipid, inflammation and gut microbiota. Consequently, its management is complex, requiring patients to self-manage their diet, lifestyle and self-care behaviors in combination with use of insulin. In addition to nutritional recommendations for all pregnant women, special attention to dietary carbohydrate (CHO) amount and type on glucose levels is especially important in GDM. Dietary CHO are diverse, ranging from simple sugars to longer-chain oligo- and poly- saccharides which have diverse effects on blood glucose, microbial fermentation and bowel function. Studies have established that dietary CHO amount and type can impact maternal glucose and nutritional recommendations advise women with GDM to limit total intake or choose complex and low glycemic CHO. However, robust maternal and infant benefits are not consistently shown. Novel approaches which help women with GDM adhere to dietary recommendations such as diabetes-specific meal replacements (which provide a defined and complete nutritional composition with slowly-digested CHO) and continuous glucose monitors (which provide unlimited monitoring of maternal glycemic fluctuations) have shown benefits on both maternal and neonatal outcomes. Continued research is needed to understand and develop tools to facilitate patient adherence to treatment goals, individualize interventions and improve outcomes.

Diabetes, Diabetic Complications, and Phosphate Toxicity: A Scoping Review

This article presents a scoping review and synthesis of research findings investigating the toxic cellular accumulation of dysregulated inorganic phosphate-phosphate toxicity-as a pathophysiological determinant of diabetes and diabetic complications. Phosphorus, an essential micronutrient, is closely linked to the cellular metabolism of glucose for energy production, and serum inorganic phosphate is often transported into cells along with glucose during insulin therapy. Mitochondrial dysfunction and apoptosis, endoplasmic reticulum stress, neuronal degeneration, and pancreatic cancer are associated with dysregulated levels of phosphate in diabetes. Ectopic calcification involving deposition of calcium-phosphate crystals is prevalent throughout diabetic complications, including vascular calcification, nephropathy, retinopathy, and bone disorders. A low-glycemic, low-phosphate dietary intervention is proposed for further investigations in the treatment and prevention of diabetes and related diabetic pathologies.

Associations between Dietary Pulses Alone or with Other Legumes and Cardiometabolic Disease Outcomes: An Umbrella Review and Updated Systematic Review and Meta-analysis of Prospective Cohort Studies

To update the European Association for the Study of Diabetes clinical practice guidelines for nutrition therapy, we conducted an umbrella review and updated systematic review and meta-analysis (SRMA) of prospective cohort studies of the association between dietary pulses with or without other legumes and cardiometabolic disease outcomes. We searched the PubMed, MEDLINE, EMBASE, and Cochrane databases through March 2019. We included the most recent SRMAs of prospective cohort studies and new prospective cohort studies published after the census dates of the included SRMAs assessing the relation between dietary pulses with or without other legumes and incidence and mortality of cardiovascular diseases (CVDs) [including coronary heart disease (CHD), myocardial infarction (MI), and stroke], diabetes, hypertension, and/or obesity. Two independent reviewers extracted data and assessed risk of bias. Risk estimates were pooled using the generic inverse variance method and expressed as risk ratios (RRs) with 95% CIs. The overall certainty of the evidence was assessed using the GRADE approach. Six SRMAs were identified and updated to include 28 unique prospective cohort studies with the following number of cases for each outcome: CVD incidence, 10,261; CVD mortality, 16,168; CHD incidence, 7786; CHD mortality, 3331; MI incidence, 2585; stroke incidence, 8570; stroke mortality, 2384; diabetes incidence, 10,457; hypertension incidence, 83,284; obesity incidence, 8125. Comparing the highest with the lowest level of intake, dietary pulses with or without other legumes were associated with significant decreases in CVD (RR: 0.92; 95% CI: 0.85, 0.99), CHD (RR: 0.90; 95% CI: 0.83, 0.99), hypertension (RR: 0.91; 95% CI: 0.86, 0.97), and obesity (RR: 0.87; 95% CI: 0.81, 0.94) incidence. There was no association with MI, stroke, and diabetes incidence or CVD, CHD, and stroke mortality. The overall certainty of the evidence was graded as "low" for CVD incidence and "very low" for all other outcomes. Current evidence shows that dietary pulses with or without other legumes are associated with reduced CVD incidence with low certainty and reduced CHD, hypertension, and obesity incidence with very low certainty. More research is needed to improve our estimates. This trial was registered at clinicaltrials.gov as NCT03555734.

Optimal Dietary Strategies for Prevention of Atherosclerotic Cardiovascular Disease in Diabetes: Evidence and Recommendations

PURPOSE OF REVIEW

This review presents the current available evidence of the effects of several dietary patterns on atherosclerotic cardiovascular disease (ASCVD) risk in patients with type 2 diabetes (T2D).

RECENT FINDINGS

Evidence demonstrates improvements in cardiovascular risk factors with some dietary patterns in the general population. However, evidence is limited for glycemic control and cardiovascular benefit in patients with T2D for Dietary Approaches to Stop Hypertension and plant-based dietary patterns. Evidence suggests that carbohydrate-restricted dietary patterns improve glycemic control and decrease the use of anti-hyperglycemic medications. The Mediterranean dietary pattern has the most evidence for glycemic control and decreased ASCVD risk in patients with T2D. There is no evidence on ASCVD outcomes in patients with T2D for any other dietary pattern. The Mediterranean dietary pattern has the most evidence for cardiovascular benefit in patients with T2D. Future research should examine the effect of dietary patterns on ASCVD outcomes.

Acute effects of an isocaloric macronutrient-matched breakfast meal containing almonds on glycemic, hormonal, and appetite responses in men with type 2 diabetes: a randomized crossover study

This randomized crossover study assessed the acute effects of almonds on postprandial glycemic, hormonal, and appetite responses in a sample of 7 men with type 2 diabetes (T2D). Participants completed 2 experimental visits during which a control (white bread, butter, cheese) and a test (white bread, almonds) meal were ingested. Energy, available carbohydrate, total lipid, and protein content were the same in both meals. Blood samples were collected in fasting state as well as 15, 30, 60, 90, 120, and 240 min postprandially for quantifying blood glucose, as well as insulin and glucagon-like peptide-1 (GLP-1) serum concentrations. Subjective appetite sensations were assessed using visual analog scales at the same time-points. Within this sample of participants, the test meal was found to be associated with lower postprandial glycemia and insulinemia, higher GLP-1 serum concentrations, decreased hunger and desire to eat, and increased fullness. The test meal was also associated with an increased estimated glucose metabolic clearance rate, indicating higher postprandial insulin sensitivity. Overall, results suggest that almonds' macronutrient subtype profile could have a beneficial impact on postprandial glycemic, hormonal, and appetite responses in men with T2D. Studies with larger sample sizes are warranted to confirm these findings. Novelty A meal containing almonds (vs. isocaloric macronutrient-matched control) induced lower glycemic and insulinemic responses. A meal containing almonds (vs. isocaloric macronutrient-matched control) induced a greater elevation in postprandial GLP-1 serum concentrations. A meal containing almonds (vs. isocaloric macronutrient-matched control) induced more favourable postprandial appetite responses.

Relation of Vegetarian Dietary Patterns With Major Cardiovascular Outcomes: A Systematic Review and Meta-Analysis of Prospective Cohort Studies

Background: Vegetarian dietary patterns are recommended for cardiovascular disease (CVD) prevention and management due to their favorable effects on cardiometabolic risk factors, however, the role of vegetarian dietary patterns in CVD incidence and mortality remains unclear.

Objective: To update the European Association for the Study of Diabetes (EASD) clinical practice guidelines for nutrition therapy, we undertook a systematic review and meta-analysis of the association of vegetarian dietary patterns with major cardiovascular outcomes in prospective cohort studies that included individuals with and without diabetes using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach.

Methods: MEDLINE, EMBASE, and Cochrane databases were searched through September 6th, 2018. We included prospective cohort studies ≥1 year of follow-up including individuals with or without diabetes reporting the relation of vegetarian and non-vegetarian dietary patterns with at least one cardiovascular outcome. Two independent reviewers extracted data and assessed study quality (Newcastle-Ottawa Scale). The pre-specified outcomes included CVD incidence and mortality (total CVD, coronary heart disease (CHD) and stroke). Risk ratios for associations were pooled using inverse variance random effects model and expressed as risk ratios (RRs) with 95% confidence intervals (CIs). Heterogeneity was assessed (Cochran Q-statistic) and quantified (I²-statistic). The overall certainty of the evidence was assessed using GRADE.

Results: Seven prospective cohort studies (197,737 participants, 8,430 events) were included. A vegetarian dietary pattern was associated with reduced CHD mortality [RR, 0.78 (CI, 0.69, 0.88)] and incidence [0.72 (0.61, 0.85)] but were not associated with CVD mortality [0.92 (0.84, 1.02)] and stroke mortality [0.92 (0.77, 1.10)]. The overall certainty of the evidence was graded as “very low” for all outcomes, owing to downgrades for indirectness and imprecision.

Conclusions: Very low-quality evidence indicates that vegetarian dietary patterns are associated with reductions in CHD mortality and incidence but not with CVD and stroke mortality in individuals with and without diabetes. More research, particularly in different populations, is needed to improve the certainty in our estimates.

Clinical Trial Registration:Clinicaltrials.gov, identifier: NCT03610828.

The Effect of Liquid Meal Replacements on Cardiometabolic Risk Factors in Overweight/Obese Individuals With Type 2 Diabetes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

The evidence for liquid meal replacements in diabetes has not been summarized. Our objective was to synthesize the evidence of the effect of liquid meal replacements on cardiometabolic risk factors in overweight/obese individuals with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Data sources included MEDLINE, EMBASE, and the Cochrane Library through 10 December 2018. We included randomized trials of ≥2 weeks assessing the effect of liquid meal replacements in weight loss diets compared with traditional weight loss diets on cardiometabolic risk factors in overweight/obese subjects with type 2 diabetes. Two independent reviewers extracted relevant data and assessed risk of bias. Data were pooled using the inverse variance method. The overall certainty of the evidence was evaluated using GRADE (Grading of Recommendations Assessment, Development and Evaluation).

RESULTS

Nine trial comparisons (N = 961 [median follow-up 24 weeks]) met eligibility criteria. Mean differences were for body weight -2.37 kg (95% CI -3.30 to -1.44), BMI -0.87 kg/m² (-1.31 to -0.42), body fat -1.66% (-2.17 to -1.15), waist circumference -2.24 cm (-3.72 to -0.77), HbA_1c -0.43% (-0.66 to -0.19) (-4.7 mmol/mol [-7.2 to -2.1]), fasting glucose -0.63 mmol/L (-0.99 to -0.27), fasting insulin -11.83 pmol/L (-23.11 to -0.54), systolic blood pressure -4.97mmHg (-7.32 to -2.62), and diastolic blood pressure -1.98 mmHg (-3.05 to -0.91). There was no effect on blood lipids. The overall certainty of the evidence was low to moderate owing to imprecision and/or inconsistency.

CONCLUSIONS

Liquid meal replacements in weight loss diets lead to modest reductions in body weight, BMI, and systolic blood pressure, and reductions of marginal clinical significance in body fat, waist circumference, HbA_1c, fasting glucose, fasting insulin, and diastolic blood pressure. More high-quality trials are needed to improve the certainty in our estimates.

James Lind Alliance research priorities: what role do carbohydrates, fats and proteins have in the management of Type 2 diabetes, and are there risks and benefits associated with particular approaches?

AIMS

To assess the role played by carbohydrates, fat and proteins in the management of Type 2 diabetes.

BACKGROUND

Diabetes research tends to reflect the interests of academics or the pharmaceutical industry, rather than those of people living with Type 2 diabetes. The James Lind Alliance and Diabetes UK addressed this issue by defining the research priorities of people living with Type 2 diabetes. Three of the top 10 research priority questions focused on lifestyle.

METHODS

A narrative review was undertaken with a structured search strategy using three databases. Search terms included the three macronutrients and Type 2 diabetes. No restrictions were placed on macronutrient quantity or length of study follow-up. Outcomes included changes in HbA_1c , body weight, insulin sensitivity and cardiovascular risk.

RESULTS

There is no strong evidence that there is an optimal ratio of macronutrients for improving glycaemic control or reducing cardiovascular risk. Challenges included defining the independent effect of macronutrient manipulation and identifying the effects of macronutrients, independent of foods and dietary patterns. Extreme intakes of macronutrients may be associated with health risks.

CONCLUSIONS

It is challenging to formulate food-based guidelines from studies based on macronutrient manipulation. Structured education should be offered to support individuals in discovering their optimal, individual dietary approach. Recommendations for dietary guidelines should be expressed in terms of foods and not macronutrients.

Increased Dairy Product Intake Modifies Plasma Glucose Concentrations and Glycated Hemoglobin: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Dairy product intake is inversely associated with the risk of type 2 diabetes (T2D) in numerous cohort studies; yet, the beneficial effects of increased dairy product intake on T2D risk factors such as fasting plasma glucose, fasting insulin, insulin resistance with the homeostasis model assessment, and glycated hemoglobin (HbA1c) remain inconclusive in clinical trials. The objective of this study was to systematically review clinical trials observing the effects of elevated compared with minimal intake of dairy products on T2D risk factors in subjects without diabetes. Five databases [Medline, EMBASE, Central, CINAHL, AMED (Allied and Complementary Medicine)] were searched to identify randomized controlled trials that used elevated quantities of dairy products from ruminant sources in comparison with a lower intake in control groups. The review outcomes were fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and HbA1c. Risk of bias and quality of evidence according to Grading of Recommendations Assessment, Development, and Evaluation were addressed. From the 10,627 citations screened, 44 studies (3016 participants) were included, 38 of which were used in the meta-analyses. Fasting glucose was positively associated with elevated dairy intake [34 studies, n = 2678; mean difference (MD): 0.07 mmol/L; 95% CI: 0.01, 0.12 mmol/L; P = 0.01, I2 = 23%]. Fasting insulin (29 studies, n = 1902; MD: -2.97 pmol/L; 95% CI: -7.05, 1.10 pmol/L; P = 0.15, I2 = 21%) and HOMA-IR (13 studies, n = 840; standardized MD: -0.07; 95% CI: -0.26, 0.12; P = 0.49, I2 = 38%) were not associated with elevated dairy consumption. HbA1c was negatively associated with elevated dairy product intake in 4 studies (n = 512; MD: -0.09%; 95% CI: -0.09%, -0.03%; P = 0.005, I2 = 0%). Most studies had high risk of bias and the quality of evidence was very low or low. In conclusion, evidence suggests that elevated dairy product intake is associated with increased fasting plasma glucose concentrations together with reduced HbA1c in nondiabetic subjects. Hence, the clinical significance of these results remains uncertain. Additional well-designed, long-term studies are required.

Positioning the Value of Dietary Carbohydrate, Carbohydrate Quality, Glycemic Index, and GI Labelling to the Canadian Consumer for Improving Dietary Patterns

The objectives of this qualitative study was to: (1) understand Canadian consumers’ knowledge and perception of dietary carbohydrates, carbohydrate quality, and the glycemic index (GI); and (2) determine Canadian’s receptiveness to GI labelling to assist with identifying and consuming foods of higher carbohydrate quality. Focus groups were recruited in Vancouver, Toronto, and Montreal and grouped according to body mass index (BMI) (NBW, normal body weight; PO, previously obese; and OW/OB, overweight/obese) and diagnosis with prediabetes and diabetes (PO (Vancouver) and OW/OB (Montreal and Toronto). Subjects in all groups linked excess consumption of carbohydrate with weight gain. PO and OW/OB groups were conflicted between perceived negative consequences and feelings of pleasure associated with carbohydrate consumption. Subjects were largely unfamiliar with the term ‘carbohydrate quality’, but were often associated with classifying carbohydrates as ‘good’ or ‘bad’. The concept of the GI resonated well across groups after exposure to corresponding educational materials. However, NBW groups largely felt that the GI was irrelevant to their dietary choices as they did not have a history of diabetes. PO and OW/OB groups associated the GI with diabetes management. The concept of a GI labelling program to help facilitate healthier carbohydrate choices was well received across all groups, especially when the low GI was interpreted as giving permission to consume foods they enjoyed eating. Results suggest that the GI could be used as a consumer-facing labelling program in Canada and assist with de-stigmatizing carbohydrate foods by helping to facilitate the consumption of carbohydrate foods that align with healthy dietary patterns.

DASH Dietary Pattern and Cardiometabolic Outcomes: An Umbrella Review of Systematic Reviews and Meta-Analyses

Background: The Dietary Approaches to Stop Hypertension (DASH) dietary pattern, which emphasizes fruit, vegetables, fat-free/low-fat dairy, whole grains, nuts and legumes, and limits saturated fat, cholesterol, red and processed meats, sweets, added sugars, salt and sugar-sweetened beverages, is widely recommended by international diabetes and heart association guidelines. Objective: To summarize the available evidence for the update of the European Association of the Study of Diabetes (EASD) guidelines, we conducted an umbrella review of existing systematic reviews and meta-analyses using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach of the relation of the DASH dietary pattern with cardiovascular disease and other cardiometabolic outcomes in prospective cohort studies and its effect on blood pressure and other cardiometabolic risk factors in controlled trials in individuals with and without diabetes. Methods: MEDLINE and EMBASE were searched through 3 January 2019. We included systematic reviews and meta-analyses assessing the relation of the DASH dietary pattern with cardiometabolic disease outcomes in prospective cohort studies and the effect on cardiometabolic risk factors in randomized and non-randomized controlled trials. Two independent reviewers extracted relevant data and assessed the risk of bias of individual studies. The primary outcome was incident cardiovascular disease (CVD) in the prospective cohort studies and systolic blood pressure in the controlled trials. Secondary outcomes included incident coronary heart disease, stroke, and diabetes in prospective cohort studies and other established cardiometabolic risk factors in controlled trials. If the search did not identify an existing systematic review and meta-analysis on a pre-specified outcome, then we conducted our own systematic review and meta-analysis. The evidence was summarized as risk ratios (RR) for disease incidence outcomes and mean differences (MDs) for risk factor outcomes with 95% confidence intervals (95% CIs). The certainty of the evidence was assessed using GRADE. Results: We identified three systematic reviews and meta-analyses of 15 unique prospective cohort studies (n = 942,140) and four systematic reviews and meta-analyses of 31 unique controlled trials (n = 4,414) across outcomes. We conducted our own systematic review and meta-analysis of 2 controlled trials (n = 65) for HbA1c. The DASH dietary pattern was associated with decreased incident cardiovascular disease (RR, 0.80 (0.76–0.85)), coronary heart disease (0.79 (0.71–0.88)), stroke (0.81 (0.72–0.92)), and diabetes (0.82 (0.74–0.92)) in prospective cohort studies and decreased systolic (MD, −5.2 mmHg (95% CI, −7.0 to −3.4)) and diastolic (−2.60 mmHg (−3.50 to −1.70)) blood pressure, Total-C (−0.20 mmol/L (−0.31 to −0.10)), LDL-C (−0.10 mmol/L (−0.20 to −0.01)), HbA1c (−0.53% (−0.62, −0.43)), fasting blood insulin (−0.15 μU/mL (−0.22 to −0.08)), and body weight (−1.42 kg (−2.03 to −0.82)) in controlled trials. There was no effect on HDL-C, triglycerides, fasting blood glucose, HOMA-IR, or CRP. The certainty of the evidence was moderate for SBP and low for CVD incidence and ranged from very low to moderate for the secondary outcomes. Conclusions: Current evidence allows for the conclusion that the DASH dietary pattern is associated with decreased incidence of cardiovascular disease and improves blood pressure with evidence of other cardiometabolic advantages in people with and without diabetes. More research is needed to improve the certainty of the estimates.

Nutrition Interventions for Type 2 Diabetes in Chinese Populations: A Scoping Review

Developing culturally appropriate diabetes nutrition interventions for immigrants could be facilitated knowing what is successful in the home country and other relevant countries. The primary purpose of this scoping review was to identify the design and delivery methods of nutrition interventions for Chinese populations with type 2 diabetes, in their home countries and as immigrants to western countries. A total of 14 articles was retrieved and included. Overall, the approaches used in China often were modelled on intensive lifestyle programs although alternative strategies were also identified. Most interventions were not focussed solely on nutrition, and only a few were conducted in community settings. Most of the interventions were delivered in a group format, while those conducted in China also included individual counselling, particularly for nutrition. In addition, the diabetes and nutrition-related outcomes, cultural relevance and acceptability, and other factors that influenced protocol compliance were considered. Improvements in blood glucose control were observed in participants in all interventions where it was measured. Participants reported increased nutritional knowledge but nutritional behaviour was generally not well documented. Trials conducted in the United States emphasized the importance of cultural adaptation of intervention programs, particularly with respect to dietary patterns and specific foods. Practice-transferable characteristics are highlighted. Research gaps included trials conducted in community settings with pragmatic implementation and evaluation, comparative trials of interventions to gauge relative effectiveness, and measuring and reporting dietary outcomes for better understanding of the impact on dietary behaviours and their relationship to health outcomes.

Dietetic Staffing and Workforce Capacity Planning in Primary Health Care

The addition of Registered Dietitians (RD) to primary health care (PHC) teams has been shown to be effective in improving health and economic outcomes with reported savings of $5 to $99 New Zealand dollars for every $1 spent on nutrition interventions. Despite proven benefits, very few Canadians have access to dietitians in PHC. This paper summarizes the literature on dietetic staffing ratios in PHC in Canada and other countries with similar PHC systems. Examples are shared to demonstrate how dietitians and others can utilize published staffing ratios to review dietitian services within their settings, identify gaps, and advocate for additional positions to meet population needs. The majority of published dietetic staffing ratios describe ranges of 1 RD: 15 000-18 500 patients, 1 RD for every 4-14 family physicians, or 1 RD for every 300-500 patients with diabetes. These staffing ratios may be inadequate as surveys report ongoing issues of limited access to dietetic counseling, under-serviced populations, and a shortage of dietitians to meet current population needs in PHC. Newer projection models based on specific population needs and ongoing workforce data are required to identify professional practice issues and accurately estimate dietetic staffing requirements in PHC.

Portfolio Dietary Pattern and Cardiovascular Disease: A Systematic Review and Meta-analysis of Controlled Trials

BACKGROUND

The evidence for the Portfolio dietary pattern, a plant-based dietary pattern that combines recognized cholesterol-lowering foods (nuts, plant protein, viscous fibre, plant sterols), has not been summarized.

OBJECTIVE

To update the European Association for the Study of Diabetes clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of controlled trials using GRADE of the effect of the Portfolio dietary pattern on the primary therapeutic lipid target for cardiovascular disease prevention, low-density lipoprotein cholesterol (LDL-C), and other established cardiometabolic risk factors.

METHODS

We searched MEDLINE, EMBASE, and The Cochrane Library through April 19, 2018. We included controlled trials ≥ 3-weeks assessing the effect of the Portfolio dietary pattern on cardiometabolic risk factors compared with an energy-matched control diet free of Portfolio dietary pattern components. Two independent reviewers extracted data and assessed risk of bias. The primary outcome was LDL-C. Data were pooled using the generic inverse-variance method and expressed as mean differences (MDs) with 95% confidence intervals (CIs). Heterogeneity was assessed (Cochran Q statistic) and quantified (I²-statistic). GRADE assessed the certainty of the evidence.

RESULTS

Eligibility criteria were met by 7 trial comparisons in 439 participants with hyperlipidemia, in which the Portfolio dietary pattern was given on a background of a National Cholesterol Education Program (NCEP) Step II diet. The combination of a portfolio dietary pattern and NCEP Step II diet significantly reduced the primary outcome LDL-C by ~17% (MD, -0.73 mmol/L, [95% CI, -0.89 to -0.56 mmol/L]) as well as non-high-density lipoprotein cholesterol, apolipoprotein B, total cholesterol, triglycerides, systolic and diastolic blood pressure, C-reactive protein, and estimated 10-year coronary heart disease (CHD) risk, compared with an NCEP Step 2 diet alone (p < 0.05). There was no effect on high-density lipoprotein cholesterol or body weight. The certainty of the evidence was high for LDL-cholesterol and most lipid outcomes and moderate for all others outcomes.

CONCLUSIONS

Current evidence demonstrates that the Portfolio dietary pattern leads to clinically meaningful improvements in LDL-C as well as other established cardiometabolic risk factors and estimated 10-year CHD risk.