Switching diets after 6-months does not result in renewed weight loss: a secondary analysis of a 12-month crossover randomized trial.

Weight change trajectory from diet and lifestyle interventions typically involves rapid weight loss followed by a weight plateau after approximately 6 months. Changing from one weight-loss diet to another at the time of the plateau could instigate renewed weight loss. Therefore, our secondary analysis aimed to assess trajectory of weight loss in a 12-month, randomized, cross-over study. Forty-two adults were randomized to eat a healthy low-fat or healthy low-carbohydrate diet for 6 months then switched to the opposite diet for an additional 6 months. Regardless of diet assignment, participants experienced rapid initial weight loss, which slowed between 3 to 6 months. After switching diets at 6 months, weight modestly decreased until 9 months, but at a rate slower than the initial 3 months and slower than the rate from 3 to 6 months. This suggests that the weight loss plateau typically seen at 6 months is physiological and cannot be overcome by simply switching to a different weight-loss diet.

Assessing the effects of alternative plant-based meats v. animal meats on biomarkers of inflammation: a secondary analysis of the SWAP-MEAT randomized crossover trial.

Alternative plant-based meats have grown in popularity with consumers recently and researchers are examining the potential health effects, or risks, from consuming these products. Because there have been no studies to date that have specifically assessed the health effects of plant-based meats on biomarkers of inflammation, the purpose of this work was to conduct a secondary analysis of the Study With Appetizing Plantfood - Meat Eating Alternatives Trial (SWAP-MEAT). SWAP-MEAT was a randomised crossover trial that involved generally healthy adults eating 2 or more servings of plant-based meats per day for 8 weeks (i.e. Plant phase) followed by 2 or more servings of animal meats per day for 8 weeks (i.e. Animal phase). Results of linear mixed-effects models indicated only 4 out of 92 biomarkers reached statistical significance. The results were contrary to our hypothesis, since we expected relative improvements in biomarkers of inflammation from the plant-based meats.

"They Eat What They Eat, I Eat What I Eat": Examining the Perspectives and Experiences of African Americans Who Adopt Plant-Based Diets.

Adopting a plant-rich or plant-based diet is one of the major recommendations for addressing obesity, overweight, and related health conditions in the United States. Currently, research on African Americans' food choices in the context of plant-based diets is limited. The primary aim of this study was to understand food-related experiences and perceptions of African Americans who were participating in the Nutritious Eating with Soul (NEW Soul) study, a culturally tailored dietary intervention focused on increasing the consumption of plant-based foods. The roles of gender and ethnicity were also examined to identify how eating patterns were chosen or maintained. Twenty-one African American adults in South Carolina, who were randomly assigned to either a vegan diet (n = 11) or a low-fat omnivorous diet (n = 10) in the NEW Soul study, completed one-on-one, qualitative interviews. Emerging themes included awareness, being in control, and identity. The study revealed that access to social support and coping strategies for addressing negative comments about plant-based food choices may be important components to include in future nutrition interventions focused on African Americans.

Effect of a ketogenic diet versus Mediterranean diet on glycated hemoglobin in individuals with prediabetes and type 2 diabetes mellitus: The interventional Keto-Med randomized crossover trial.

BACKGROUND: Consensus has not been reached on what constitutes an optimal diet in individuals with prediabetes and type 2 diabetes mellitus (T2DM), especially between low-carbohydrate options. OBJECTIVES: We compared 2 low-carbohydrate diets with 3 key similarities (incorporating nonstarchy vegetables and avoiding added sugars and refined grains) and 3 key differences (incorporating compared with avoiding legumes, fruits, and whole, intact grains) for their effects on glucose control and cardiometabolic risk factors in individuals with prediabetes and T2DM. METHODS: Keto-Med was a randomized, crossover, interventional trial. Forty participants aged ≥18 years with prediabetes or T2DM followed the well-formulated ketogenic diet (WFKD) and the Mediterranean-plus diet (Med-Plus) for 12 weeks each, in random order. The diets shared the 3 key similarities noted above. The Med-Plus incorporated legumes, fruits, and whole, intact grains, while the WFKD avoided them. The primary outcome was the percentage change in glycated hemoglobin (HbA1c) after 12 weeks on each diet. Secondary and exploratory outcomes included percentage changes in body weight, fasting insulin, glucose, and blood lipids; average glucose from continuous glucose monitor (CGM), and nutrient intake. RESULTS: The primary analysis was of 33 participants with complete data. The HbA1c values did not differ between diets at 12 weeks. Triglycerides decreased more for the WFKD [percentage changes, -16% (SEM, 4%) compared with -5% (SEM, 6%) for the Med-Plus; P = 0.02] and LDL cholesterol was higher for the WFKD [percentage changes, +10% (SEM, 4%) compared with -5% (SEM, 5%) for the Med-Plus; P = 0.01]. Weight decreased 8% (SEM, 1%) compared with 7% (SEM, 1%) and HDL cholesterol increased 11% (SEM, 2%) compared with 7% (SEM, 3%) for the WFKD compared with the Med-Plus, respectively; however, there was a significant interaction of diet × order for both. Participants had lower intakes of fiber and 3 nutrients on the WFKD compared with the Med-Plus. Twelve-week follow-up data suggest the Med-Plus is more sustainable. CONCLUSIONS: HbA1c values were not different between diet phases after 12 weeks, but improved from baseline on both diets, likely due to several shared dietary aspects. The WFKD led to a greater decrease in triglycerides, but also had potential untoward risks from elevated LDL cholesterol and lower nutrient intakes from avoiding legumes, fruits, and whole, intact grains, as well as being less sustainable. This trial was registered at clinicaltrials.gov as NCT03810378.

Examining demographic characteristics and food access indicators from the location of vegan soul food restaurants in the south.

Objective: There have been a number of soul food restaurants serving exclusively vegan meals opening up across the country to appeal to African Americans and others interested in eating healthier soul foods. This study determined the number of restaurants serving vegan soul foods in the South and identified the locations of these restaurants in order to understand the characteristics of the surrounding communities that they serve.Design: Two reviewers identified restaurants using standardized search criteria for menu items in the 16 states (and the District of Columbia) that are categorized as being in the South from the Census Bureau. Mean percentage of African Americans, poverty rates, and obesity rates by county where restaurants were located were collected via census data. Restaurants were classified as being in or out of a food desert zone using the United States Department of Agriculture's (USDA) food atlas map (0.5- and 1.0-mile radius). T-tests were conducted to test for differences in the census data between the restaurants that were considered to be in and out of a food desert zone.Results: Overall, 45 restaurants met the inclusion criteria. Counties where restaurants were located had a mean African American population of 36.5 ± 18.5%, mean poverty rate of 15.5 ± 3.85% and mean obesity rate of 26.8 ± 4.8%. More than one third (n = 18, 40.0%) of the restaurants were considered to be in a food desert zone. There were no significant differences in the mean population, obesity, and poverty rates between restaurants classified in a food desert zone and restaurants not located in a food desert zone.Conclusion: A significant number of restaurants were classified in food desert zones, implying their potential to provide healthier meals by serving vegan soul foods to residents in the surrounding neighborhoods. Future work should assess how these restaurants might influence healthier eating habits in their communities.

Ultra-processed Foods, Weight Gain, and Co-morbidity Risk.

PURPOSE OF REVIEW: The purpose of this review is to provide an update on the available data regarding the associations of Ultra-processed food (UPF) consumption with food intake and possible underlying mechanisms relating UPF consumption to weight gain and co-morbidities. RECENT FINDINGS: In primarily observational studies, UPF consumption is consistently associated with an increased risk for weight gain among adults and children and increased risk for adiposity-related co-morbidities in adults. In a single mechanistic study, consumption of UPFs led to increased energy intake and weight gain relative to whole foods. UPFs tend to be more energy-dense than nutrient-dense, and UPF consumption is associated with increased adiposity and co-morbidity risk. These data suggest that recommendations to limit UPF consumption may be beneficial to health - though further mechanistic studies are needed.

Findings from Diet Comparison Difficult to Interpret in the Absence of Adherence Assessment. Comment on Tricò et al. Effects of Low-Carbohydrate versus Mediterranean Diets on Weight Loss, Glucose Metabolism, Insulin Kinetics and ß-Cell Function in Morbidly Obese Individuals. Nutrients 2021, 13, 1345.

We read, with interest, the recent publication by Tricò et al. [...].

Benefits of Low Carbohydrate Diets: a Settled Question or Still Controversial?

PURPOSE OF REVIEW: The purpose of this review was to provide an update on the available data on the benefits of low-carbohydrate (low-carb) diets for weight management and type 2 diabetes (T2DM) and determine if low-carb diets were a settled question or still controversial. RECENT FINDINGS: Most of the recent published literature in this area consists of reviews of past trials, with a relatively smaller number of recent trials. Low-carb is most commonly compared to low-fat, with problematically inconsistent definitions of both. There are numerous challenges in trying to draw clear conclusions about efficacy and effectiveness. Short-term vs. long-term effects can differ, which is likely impacted by adherence. Adherence is very different between metabolic chamber or feeding studies vs. free-living. Body weight alone is a crude measure that fails to capture potentially important differences in lean-mass, fat-mass, and body water. Benefits for glycemic control need to be balanced with impacts on non-glycemic outcomes such as LDL-cholesterol, the microbiome, and inflammation. It is important to differentiate between low-carb and very-low carbohydrate diets (VLCD). To date no large-scale long-term clinical trials have been conducted testing whether low-carb diets can prevent T2DM. Many issues regarding benefits and risks of low-carb diets remain controversial or unresolved, particularly for VLCD. Some of the recent, better studies highlighted in this review suggest strategies for resolving these controversies.

Sustainable Diets for Cardiovascular Disease Prevention and Management.

PURPOSE OF REVIEW: Healthy dietary patterns are recommended for prevention of cardiovascular disease, which remains the leading cause of morbidity and mortality globally. In this review, we discuss dietary patterns that are not only optimal for CVD prevention and management but also sustainable in maximizing health, environmental, and economic benefits. RECENT FINDINGS: The growing literature on sustainable diets in the context of environmental sustainability includes subtopics of climate change, land use, biodiversity loss, freshwater use, and reactive nitrogen emissions. Similarly, economic sustainability, beyond the retail cost of food, extends to healthcare costs and the economic costs of environmental destruction related to current agricultural practices and food choices. Dietary patterns that are high in plant foods and low in animal foods could maximize health, environmental, and economic benefits; however, questions remain about how to best promote these patterns to achieve wider adoption in an environmentally and economically sustainable way.

Adherence to Ketogenic and Mediterranean Study Diets in a Crossover Trial: The Keto-Med Randomized Trial.

Adherence is a critical factor to consider when interpreting study results from randomized clinical trials (RCTs) comparing one diet to another, but it is frequently not reported by researchers. The purpose of this secondary analysis of the Keto-Med randomized trial was to provide a detailed examination and comparison of the adherence to the two study diets (Well Formulated Ketogenic Diet (WFKD) and Mediterranean Plus (Med-Plus)) under the two conditions: all food being provided (delivered) and all food being obtained by individual participants (self-provided). Diet was assessed at six time points including baseline (×1), week 4 of each phase when participants were receiving food deliveries (×2), week 12 of each phase when participants were preparing and providing food on their own (×2), and 12 weeks after participants completed both diet phases and were free to choose their own diet pattern (×1). The adherence scores for WFKD and Med-Plus were developed specifically for this study. Average adherence to the two diet patterns was very similar during both on-study time points of the intervention. Throughout the study, a wide range of adherence was observed among participants-for both diet types and during both the delivery phase and self-provided phase. Insight from this assessment of adherence may aid other researchers when answering the important question of how to improve behavioral adherence during dietary trials. This study is registered at clinicaltrials.gov NCT03810378.

The role of self-efficacy and information processing in weight loss during an mHealth behavioral intervention.

Self-efficacy (SE) and information processing (IP) may be important constructs to target when designing mHealth interventions for weight loss. The goal of this study was to examine the relationship between SE and IP with weight loss at six-months as part of the Dietary Interventions Examining Tracking with mobile study, a six-month randomized trial with content delivered remotely via twice-weekly podcasts. Participants were randomized to self-monitor their diet with either a mobile app (n = 42) or wearable Bite Counter device (n = 39). SE was assessed using the Weight Efficacy Life-Style Questionnaire and the IP variables assessed included user control, cognitive load, novelty, elaboration. Regression analysis examined the relationship between weight loss, SE change & IP at six months. Results indicate that elaboration was the strongest predictor of weight loss (ß =-0.423, P = 0.011) among all SE & IP variables and that for every point increase in elaboration, participants lost 0.34 kg body weight.

A randomized crossover trial on the effect of plant-based compared with animal-based meat on trimethylamine-N-oxide and cardiovascular disease risk factors in generally healthy adults: Study With Appetizing Plantfood-Meat Eating Alternative Trial (SWAP-MEAT).

BACKGROUND: Despite the rising popularity of plant-based alternative meats, there is limited evidence of the health effects of these products. OBJECTIVES: We aimed to compare the effect of consuming plant-based alternative meat (Plant) as opposed to animal meat (Animal) on health factors. The primary outcome was fasting serum trimethylamine-N-oxide (TMAO). Secondary outcomes included fasting insulin-like growth factor 1, lipids, glucose, insulin, blood pressure, and weight. METHODS: SWAP-MEAT (The Study With Appetizing Plantfood-Meat Eating Alternatives Trial) was a single-site, randomized crossover trial with no washout period. Participants received Plant and Animal products, dietary counseling, lab assessments, microbiome assessments (16S), and anthropometric measurements. Participants were instructed to consume ≥2 servings/d of Plant compared with Animal for 8 wk each, while keeping all other foods and beverages as similar as possible between the 2 phases. RESULTS: The 36 participants who provided complete data for both crossover phases included 67% women, were 69% Caucasian, had a mean ± SD age 50 ± 14 y, and BMI 28 ± 5 kg/m2. Mean ± SD servings per day were not different by intervention sequence: 2.5 ± 0.6 compared with 2.6 ± 0.7 for Plant and Animal, respectively (P = 0.76). Mean ± SEM TMAO concentrations were significantly lower overall for Plant (2.7 ± 0.3) than for Animal (4.7 ± 0.9) (P = 0.012), but a significant order effect was observed (P = 0.023). TMAO concentrations were significantly lower for Plant among the n = 18 who received Plant second (2.9 ± 0.4 compared with 6.4 ± 1.5, Plant compared with Animal, P = 0.007), but not for the n = 18 who received Plant first (2.5 ± 0.4 compared with 3.0 ± 0.6, Plant compared with Animal, P = 0.23). Exploratory analyses of the microbiome failed to reveal possible responder compared with nonresponder factors. Mean ± SEM LDL-cholesterol concentrations (109.9 ± 4.5 compared with 120.7 ± 4.5 mg/dL, P = 0.002) and weight (78.7 ± 3.0 compared with 79.6 ± 3.0 kg, P < 0.001) were lower during the Plant phase. CONCLUSIONS: Among generally healthy adults, contrasting Plant with Animal intake, while keeping all other dietary components similar, the Plant products improved several cardiovascular disease risk factors, including TMAO; there were no adverse effects on risk factors from the Plant products.This trial was registered at clinicaltrials.gov as NCT03718988.

The Nutritious Eating with Soul (NEW Soul) Study: Study design and methods of a two-year randomized trial comparing culturally adapted soul food vegan vs. omnivorous diets among African American adults at risk for heart disease.

BACKGROUND: Previous research has found that African American (AA) vegetarians/vegans have a significantly lower body mass index and risk of hypertension compared to omnivores. OBJECTIVES: The Nutritious Eating with Soul (NEW Soul) study partnered with local soul food restaurants/chefs to deliver two behavioral nutrition interventions to AA adults. NEW Soul examines the impact of two different culturally tailored diets (vegan and omnivorous low-fat) on changes in risk factors for cardiovascular disease (CVD). METHODS: AA adults with overweight or obesity are recruited from the community in the Midlands of South Carolina. Eligible participants are randomized to follow one of two different culturally-adapted, soul food diets: a vegan diet emphasizing minimally-processed whole foods from plants or a low-fat omnivorous diet. Participants attend weekly group classes for the first six months, bi-weekly for the next six months, and monthly meetings for the last year. In addition to face-to-face content, participants also have access to private Facebook groups for their diet, podcasts, and online newsletters starting at six months. Primary outcomes include changes in body weight and CVD risk factors (lipids, blood pressure, glucose, and insulin) at 12 months. Secondary outcomes include changes in dietary intake. Participants complete assessments at baseline and at months 6, 12, and 24. CONCLUSIONS: The NEW Soul study is an innovative intervention aimed at improving dietary intake while maintaining traditional AA cultural food choices. Primary outcomes are expected by 2021.

Impact of a 12-month Inflammation Management Intervention on the Dietary Inflammatory Index, inflammation, and lipids.

BACKGROUND AND AIMS: The objective of this study was to assess the feasibility (ability to recruit participants and develop the 12-month intervention), acceptability (retention of participants in the intervention), and impact on systemic inflammation and Dietary Inflammatory Index (DII®) scores over a 12-month DII-based intervention. METHODS: Adults were recruited to participate in a self-selection trial (intervention: n = 61, in-person classes; control: n = 34, newsletters). Classes included participatory cooking and dietary recommendations focused on consuming a plant-based diet rich in anti-inflammatory foods (spices, vegetables, etc.). Changes in markers of inflammation, lipids, and DII were analyzed using general linear models with repeated measurements. RESULTS: At 3 months, intervention participants had significantly lower DII scores (-2.66 ± 2.44) compared to controls (-0.38 ± 2.56) (p < 0.01); but not at 12 months (P = 0.10). The only biomarker to approach a significant group effect or group-by-time interaction was CRP (P = 0.11 for the group-by-time interaction). CRP decreased by -0.65 mg/L (95%CI = 0.10-1.20, P = 0.02) at 12 months in the intervention group; no significant decrease was seen for the control group. With both groups combined at 3 months, those with the greatest decrease/improvement in DII score (tertile 1) compared with those whose scores increased (tertile 3) had greater reductions in CRP (-1.09 vs. +0.52 mg/L, P = 0.04), total cholesterol (-9.38 vs. +12.02 mg/dL, P = 0.01), and LDL cholesterol (-11.99 vs. +7.16 mg/dL, P = 0.01). CONCLUSIONS: Although the intervention group had reductions in DII and CRP, main inflammation and lipid outcomes did not differ between groups. Overall, those participants with the largest reduction in DII scores had the largest reductions in CRP and LDL and total cholesterol. Future interventions may need to have more components in place to support maintenance and continued reductions in the DII. CLINICALTRIALS. GOV IDENTIFIER: NCT02382458.

Using Commercial Physical Activity Trackers for Health Promotion Research: Four Case Studies.

BACKGROUND: Wearable physical activity (PA) trackers are becoming increasingly popular for intervention and assessment in health promotion research and practice. The purpose of this article is to present lessons learned from four studies that used commercial PA tracking devices for PA intervention or assessment, present issues encountered with their use, and provide guidelines for determining which tools to use. METHOD: Four case studies are presented that used PA tracking devices (iBitz, Zamzee, FitBit Flex and Zip, Omron Digital Pedometer, Sensewear Armband, and MisFit Flash) in the field-two used the tools for intervention and two used the tools as assessment methods. RESULTS: The four studies presented had varying levels of success with using PA devices and experienced several issues that impacted their studies, such as companies that went out of business, missing data, and lost devices. Percentage ranges for devices that were lost were 0% to 29% and was 0% to 87% for those devices that malfunctioned or lost data. CONCLUSIONS: There is a need for low-cost, easy-to-use, accurate PA tracking devices to use as both intervention and assessment tools in health promotion research related to PA.

Baseline markers of inflammation, lipids, glucose, and Dietary Inflammatory Index scores do not differ between adults willing to participate in an intensive inflammation reduction intervention and those who do not.

BACKGROUND:: Chronic inflammation is associated with numerous chronic diseases and can be managed with diet. AIM:: The purpose of this study was to examine differences in baseline characteristics and plasma inflammation levels between two groups of participants that participated in an intensive, lifestyle intervention or a remotely delivered intervention. This work also assessed the association between Dietary Inflammatory Index (DII)® scores and participants' inflammatory and metabolic biomarkers at baseline. METHOD:: Ninety-five participants (61 intervention, 34 control) chose to enroll in either a 12-month intervention consisting of a face-to-face nutrition, physical activity, and stress management intervention or a remotely-delivered intervention (control group) focusing on general cancer prevention. The intervention group met at the University of South Carolina for classes and the control group had materials emailed to them. A quantile regression was used to compare participants' high-sensitivity C-reactive protein and interleukin-6 levels. Multiple linear regression was used to determine the association between DII scores and biomarkers. RESULTS:: There were significant differences in age, body mass index, body fat percentage, and blood pressure between groups, but there were no differences in levels of inflammatory biomarkers. Values of interleukin-6 at the 90th percentile of its distribution were 8.31 pg/ml higher among those in DII quartile 4 compared with quartile 1 ( p = 0.02). All other outcomes were not significant. CONCLUSION:: Given similar levels of inflammatory biomarkers, participants opting for the control group would also have benefited from a more intensive lifestyle intervention focusing on reducing inflammation.

The effects of meal-timing on self-rated hunger and dietary inflammatory potential among a sample of college students.

College is an important time for young adults to establish healthy eating habits since students are at risk for gaining weight during the college years. An emerging area of research is examining the effect of meal-timing, which involves the timing of food intake throughout the day, in an effort to improve satiety and bodyweight. The purpose of this study was to examine the use of meal-timing among a sample of college students and to assess what aspects from an intervention could help them to adhere to meal-timing long term. Participants were randomly assigned to either a daytime group (≤30% total kcals after 5 pm) or a nighttime group (≥50% total kcals after 5 pm). After completing the intervention, almost half of participants (49%) reported they could adhere to meal-timing long-term. Having more resources that support meal-timing are needed to help students potentially achieve a healthy weight and prevent chronic diseases.

Determinants of Attendance at a Physical Activity Focused Afterschool Program in Elementary School Children.

Afterschool youth physical activity (PA) programs provide opportunities for increasing children's time engaged in moderate-to-vigorous physical activity (MVPA). However, low program attendance reduces the benefits of participating in these programs. The purpose of this study was to determine if enjoyment, athletic competence and motivation for PA predict youth attendance at a free afterschool PA program from 3rd to 5th grade. Data were collected from a larger randomized community trial examining the effectiveness of an afterschool program for increasing opportunities to engage in MVPA. Data were collected twice annually (fall/spring) over 3 school years (3rd - 5th grade) in 9 schools. Analyses were stratified by grade and sex, and a series of multi-level linear regression models were utilized to determine if baseline levels of the psychosocial determinants predicted annual attendance as a percentage of afterschool sessions attended. Amotivation for PA was negatively associated with attendance in boys and non-self-determined extrinsic motivation was positively associated with attendance in girls in the 5th grade. Age was associated with a 13.72% reduction in attendance in the 3rd grade, a 12.87% attendance reduction in the 4th grade, and a 7.93% attendance in reduction in the 5th grade. Race was also associated with attendance. Non-White youth attended the program 13.56% less in the 3rd grade, 17.35% less in the 4th grade, and 21.53% less in the 5th grade than White youth. The findings suggest that attendance to PA afterschool programming may be associated with children's motivational characteristics, but that other variables should be identified for further research.