Effect of a Dietary Intervention on Insulin Requirements and Glycemic Control in Type 1 Diabetes: A 12-Week Randomized Clinical Trial.

This study compared the effects of a low-fat vegan diet to those of a portion-controlled diet in people with type 1 diabetes. Over 12 weeks, the average total daily dose of insulin decreased significantly and insulin sensitivity increased significantly in the vegan group, while no significant changes were observed in the group receiving the portion-controlled diet. Total and LDL cholesterol decreased in the vegan group, as did the ratio of blood urea nitrogen to creatinine. A1C decreased in both groups. These findings suggest that a low-fat vegan diet may yield improvements in insulin sensitivity, insulin requirements, glycemic control, and markers of cardiovascular and renal health compared with a portion-controlled diet in people with type 1 diabetes.

Weight management using meal replacements and cardiometabolic risk reduction in individuals with pre-diabetes and features of metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials.

This review synthesized the evidence from randomized controlled trials comparing the effect of meal replacements (MRs) as part of a weight loss intervention with conventional food-based weight loss diets on cardiometabolic risk in individuals with pre-diabetes and features of metabolic syndrome. MEDLINE, EMBASE, and Cochrane Library were searched through January 16, 2024. Data were pooled using the generic inverse variance method and expressed as mean difference [95% confidence intervals]. The overall certainty of the evidence was assessed using GRADE. Ten trials (n = 1254) met the eligibility criteria. MRs led to greater reductions in body weight (-1.38 kg [-1.81, -0.95]), body mass index (BMI, -0.56 kg/m2 [-0.78, -0.34]), waist circumference (-1.17 cm [-1.93, -0.41]), HbA1c (-0.11% [-0.22, 0.00]), LDL-c (-0.18 mmol/L [-0.28, -0.08]), non-HDL-c (-0.17 mmol/L [-0.33, -0.01]), and systolic blood pressure (-2.22 mmHg [-4.20, -0.23]). The overall certainty of the evidence was low to moderate owing to imprecision and/or inconsistency. The available evidence suggests that incorporating MRs into a weight loss intervention leads to small important reductions in body weight, BMI, LDL-c, non-HDL-c, and systolic blood pressure, and trivial reductions in waist circumference and HbA1c, beyond that seen with conventional food-based weight loss diets.

Does diet quality matter? A secondary analysis of a randomized clinical trial.

This secondary analysis assessed the association of a plant-based index (PDI), healthful (hPDI), and unhealthful (uPDI), with weight loss in overweight adults. Participants (n = 244) were randomly assigned to a vegan (n = 122) or control group (n = 122) for 16 weeks. Three-day dietary records were analyzed and PDI indices were calculated. A repeated measure ANOVA was used for statistical analysis. All three scores increased in the vegan group; the effect sizes were: PDI +10.6 (95% CI +8.6 to +12.6; p < 0.001); hPDI +10.9 (95% CI +8.4 to +13.4; p < 0.001); and uPDI +5.4 (95% CI +3.4 to +7.4; p < 0.001). The change in all three scores significantly correlated with change in body weight: PDI (r = -0.40; p < 0.001); hPDI (r = -0.37; p < 0.001); and uPDI (r = -0.21; p = 0.002). These findings suggest that minimizing the consumption of animal products and oil may be an effective weight loss strategy in overweight adults. ClinicalTrials.gov number, NCT02939638.

A dietary intervention for postmenopausal hot flashes: A potential role of gut microbiome. An exploratory analysis.

OBJECTIVE: This study examined the role of gut microbiome changes in mediating the effects of a dietary intervention on the frequency and severity of postmenopausal vasomotor symptoms METHODS: Postmenopausal women (n = 84) reporting ≥2 moderate-to-severe hot flashes daily were randomly assigned, in 2 successive cohorts, to an intervention including a low-fat, vegan diet and cooked soybeans (½ cup [86 g] daily) or to stay on their usual diet. Over a 12-week period, frequency and severity of hot flashes were recorded with a mobile application. In a subset of 11 women, gut microbiome was analyzed at baseline and after 12 weeks of the dietary intervention (low-fat vegan diet with soybeans), using deep shotgun metagenomic sequencing. Differences in the microbiome between baseline and 12 weeks were assessed by comparing alpha diversity with Wilcoxon signed rank tests, beta diversity with permanovaFL, and taxon abundance with Wilcoxon signed rank tests. Pearson correlations were used to assess the association between changes in hot flashes and gut bacteria. RESULTS: In the subset for which microbiome testing was done, total hot flashes decreased by 95 % during the dietary intervention (p = 0.007); severe hot flashes disappeared (from 0.6 to 0.0/day; p = 0.06); and moderate-to-severe hot flashes decreased by 96 % (p = 0.01). Daytime and nighttime hot flashes were reduced by 96 % (p = 0.01) and 94 % (p = 0.004), respectively. Alpha and beta diversity did not significantly differ in the intervention group between baseline and 12 weeks. Two families (Enterobacteriaceae and Veillonellaceae), 5 genera (Erysipelatoclostridium, Fusicatenibacter, Holdemanella, Intestinimonas, and Porphyromonas), and 6 species (Clostridium asparagiforme, Clostridium innocuum, Bacteroides thetaiotaomicron, Fusicatenibacter saccharivorans, Intestinimonas butyriciproducens, Prevotella corporis, and Streptococcus sp.) were differentially abundant, but after correction for multiple comparisons, these differences were no longer significant. Changes in the relative abundance of Porphyromonas and Prevotella corporis were associated with the reduction in severe day hot flashes both unadjusted (r = 0.61; p = 0.047; and r = 0.69; p = 0.02), respectively), and after adjustment for changes in body mass index (r = 0.63; p = 0.049; and r = 0.73; p = 0.02), respectively). Changes in relative abundance of Clostridium asparagiforme were associated with the reduction in total severe hot flashes (r = 0.69; p = 0.019) and severe night hot flashes (r = 0.82; p = 0.002) and the latter association remained significant after adjustment for changes in body mass index (r = 0.75; p = 0.01). CONCLUSIONS: This exploratory analysis revealed potential associations between changes in vasomotor symptoms in response to a diet change and changes in the gut microbiome. Larger randomized clinical trials are needed to investigate these findings.

Vegan Diet and Food Costs Among Adults With Overweight: A Secondary Analysis of a Randomized Clinical Trial.

This secondary analysis of a randomized clinical trial investigates the effects of a vegan diet on total food costs per day.

Dietary advanced glycation products and their associations with insulin sensitivity and body weight: A 16-week randomized clinical trial.

Background: Evidence suggests that changes in advanced glycation end-products (AGEs) may influence body weight. Previous studies have focused on cooking methods as the primary way how to reduce the dietary AGEs but little is known about the effects of a change in diet composition. Objective: The aim of this study was to assess the effects of a low-fat plant-based diet on dietary AGEs and test the association with body weight, body composition, and insulin sensitivity. Methods: Participants who were overweight (n = 244) were randomly assigned to an intervention (low-fat plant-based) (n = 122) or control group (n = 122) for 16 weeks. Before and after the intervention period, body composition was measured by dual X-ray absorptiometry. Insulin sensitivity was assessed with the predicted insulin sensitivity index (PREDIM). Three-day diet records were analyzed using the Nutrition Data System for Research software and dietary AGEs were estimated, using a database. Repeated measure ANOVA was used for statistical analysis. Results: Dietary AGEs decreased in the intervention group by 8768 ku/day on average (95% -9611 to -7925; p < 0.001), compared with the control group (-1608; 95% CI -2709 to -506; p = 0.005; treatment effect -7161 ku/day [95% CI -8540 to -5781]; Gxt, p < 0.001). Body weight decreased by 6.4 kg in the intervention group, compared with 0.5 kg in the control group (treatment effect -5.9 kg [95% CI -6.8 to -5.0]; Gxt, p < 0.001), largely due to a reduction in fat mass, notably visceral fat. PREDIM increased in the intervention group (treatment effect +0.9 [95% CI + 0.5 to +1.2]; p < 0.001). Changes in dietary AGEs correlated with changes in body weight (r = +0.41; p < 0.001), fat mass (r = +0.38; p < 0.001), visceral fat (r = +0.23; p < 0.001), and PREDIM (r = -0.28; p < 0.001), and remained significant even after adjustment for changes in energy intake (r = +0.35; p < 0.001 for body weight; r = +0.34; p < 0.001 for fat mass; r = +0.15; p = 0.03 for visceral fat; and r = -0.24; p < 0.001 for PREDIM). Conclusions: Dietary AGEs decreased on a low-fat plant-based diet, and this decrease was associated with changes in body weight, body composition, and insulin sensitivity, independent of energy intake. These findings demonstrate positive effects of qualitative dietary changes on dietary AGEs and cardiometabolic outcomes. Clinical Trial Registry Number: NCT02939638.

Dietary advanced glycation end-products and postmenopausal hot flashes: A post-hoc analysis of a 12-week randomized clinical trial.

OBJECTIVE: Postmenopausal hot flashes are associated with an increased risk of cardiovascular disease and diabetes. Because dietary advanced glycation end-products (AGEs) may act as endocrine disruptors, this study examined the potential association of modifications to the intake of dietary AGEs with the frequency and severity of postmenopausal hot flashes. METHODS: Postmenopausal women (n = 84) reporting ≥2 moderate-to-severe hot flashes daily were randomly assigned to either the intervention group or the control group. The former were asked to follow a low-fat, vegan diet, including cooked soybeans (1/2 cup [86 g]/day) for 12 weeks, and the latter continued their usual diets for 12 weeks. Frequency and severity of hot flashes were recorded with a mobile application. Three-day diet records were analyzed using the Nutrition Data System for Research software and dietary AGEs were estimated, using a database. Seventy-one participants completed the whole study and 63 provided complete hot flash and dietary data for the AGEs analysis (n = 31 in the intervention and n = 24 in the control group). Pearson correlations were used to assess the association between changes in hot flashes and dietary AGEs. RESULTS: Dietary AGEs decreased in the intervention group by 73 %, that is by 5509 ku/day on average (95 % -7009 to -4009; p < 0.001), compared with the control group (+458; 95 % CI -835 to +1751; p = 0.47; treatment effect -5968 ku/day [95 % CI -7945 to -3991]; Gxt, p < 0.001). Severe hot flashes decreased by 92 % (p < 0.001) and moderate-to-severe hot flashes decreased by 88 % in the intervention group (p < 0.001). Changes in dietary AGEs correlated with changes in severe (r = +0.39; p = 0.002) and moderate hot flashes (r = +0.34; p = 0.009) and remained significant after adjustment for changes in energy intake (r = +0.45; p < 0.001; and r = +0.37; p = 0.004, respectively) and changes in body mass index (r = +0.37; p = 0.004; and r = +0.27; p = 0.04, respectively). The reduction in dietary AGEs required to achieve a predicted reduction in hot flashes by 1/day was 6933 ku/day for severe and 4366 ku/day for moderate-to-severe hot flashes. CONCLUSIONS: The reduction in dietary AGEs with a low-fat plant-based diet was associated with a significant reduction in the frequency of severe and moderate-to-severe postmenopausal hot flashes, independent of changes in energy intake and weight loss. Plant-based diets could be used not only to alleviate vasomotor symptoms in postmenopausal women, but also to reduce other health risks associated with AGEs. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04587154.

Nutrition in the prevention and treatment of endometriosis: A review.

Endometriosis is characterized by the presence of endometrial tissues outside the uterine lining, typically on the external surface of the uterus, the ovaries, fallopian tubes, abdominal wall, or intestines. The prevalence of endometriosis in North America, Australia, and Europe is ~1-5% in women of reproductive age. Treatment options for endometriosis are limited. While over-the-counter medications may be used to reduce acute pain, hormonal treatments are common and may interfere with fertility. In more severe cases, laparoscopic excision procedures and even hysterectomies are used to treat the pain associated with endometriosis. Nutritional interventions may be helpful in the prevention and treatment of endometriosis and associated pain. Reducing dietary fat and increasing dietary fiber have been shown to reduce circulating estrogen concentrations, suggesting a potential benefit for individuals with endometriosis, as it is an estrogen-dependent disease. Meat consumption is associated with greater risk of developing endometriosis. Anti-inflammatory properties of plant-based diets may benefit women with endometriosis. Additionally, seaweed holds estrogen-modulating properties that have benefitted postmenopausal women and offers potential to reduce estradiol concentrations in pre-menopausal women. Furthermore, consumption of vitamin D has been shown to reduce endometrial pain via increased antioxidant capacity and supplementation with vitamins C and E significantly reduced endometriosis symptoms, compared with placebo. More randomized clinical trials are needed to elucidate the role of diet in endometriosis.

Combination of Multiple Low-Risk Lifestyle Behaviors and Incident Type 2 Diabetes: A Systematic Review and Dose-Response Meta-analysis of Prospective Cohort Studies.

OBJECTIVE: Combined low-risk lifestyle behaviors (LRLBs) have been associated with a reduction in type 2 diabetes risk. This relationship has not been systematically quantified. RESEARCH DESIGN AND METHODS: A systematic review and meta-analysis was conducted to assess the association of combined LRLBs with type 2 diabetes. Databases were searched up to September 2022. Prospective cohort studies reporting the association between a minimum of three combined LRLBs (including healthy diet) with incident type 2 diabetes were included. Independent reviewers extracted data and assessed study quality. Risk estimates of extreme comparisons were pooled using a random-effects model. Global dose-response meta-analysis (DRM) for maximum adherence was estimated using a one-stage linear mixed model. The certainty of the evidence was assessed using GRADE (Grading of Recommendations, Assessment, Development and Evaluations). RESULTS: Thirty cohort comparisons (n = 1,693,753) involving 75,669 incident type 2 diabetes cases were included. LRLBs, with author-defined ranges, were healthy body weight, healthy diet, regular exercise, smoking abstinence or cessation, and light alcohol consumption. LRLBs were associated with 80% lower risk of type 2 diabetes (relative risk [RR] 0.20; 95% CI 0.17-0.23), comparing the highest with lowest adherence. Global DRM for maximum adherence to all five LRLBs reached 85% protection (RR 0.15; 95% CI 0.12-0.18). The overall certainty of the evidence was graded as high. CONCLUSIONS: There is a very good indication that a combination of LRLBs that includes maintaining a healthy bodyweight, healthy diet, regular exercise, smoking abstinence or cessation, and light alcohol consumption is associated with a lower risk of incident type 2 diabetes.

The Role of Nutrition in COVID-19: Taking a Lesson from the 1918 H1N1 Pandemic.

In looking for solutions to the COVID-19 pandemic, important lessons come from the H1N1 influenza pandemic of 1918-1919. During the H1N1 influenza pandemic, the soldiers had better outcomes than the civilian populations, but the best outcomes were reported by a Seventh-day Adventist seminary, where a plant-based diet was provided. The diet has been described as including grains, fruits, nuts, and vegetables. A few clinical trials have also assessed the role of nutrition in COVID-19. One study with almost six hundred thousand participants showed that those with a high consumption of fruits and vegetables had a reduced risk of COVID-19 of any severity by 9% and a reduced risk of severe COVID-19 by 41%. Another study in healthcare workers who were frequently exposed to COVID-19 in their clinical practice has demonstrated that those who reported being on a plant-based diet had a 73% lower risk of moderate-to-severe COVID-19. Based on the lessons from 1918 and the recent nutrition research in COVID-19, it seems plausible that a healthful plant-based diet may be a powerful tool to decrease the risk of severe COVID-19 and should be promoted as one of the public health safety measures.

A dietary intervention for vasomotor symptoms of menopause: a randomized, controlled trial.

OBJECTIVE: Postmenopausal vasomotor symptoms disrupt quality of life. This study tested the effects of a dietary intervention on vasomotor symptoms and menopause-related quality of life. METHODS: Postmenopausal women (n = 84) reporting at least two moderate-to-severe hot flashes daily were randomly assigned, in two successive cohorts, to an intervention including a low-fat, vegan diet and cooked soybeans (½ cup [86 g] daily) or to a control group making no dietary changes. During a 12-week period, a mobile application was used to record hot flashes (frequency and severity), and vasomotor, psychosocial, physical, and sexual symptoms were assessed with the Menopause-Specific Quality of Life questionnaire. Between-group differences were assessed for continuous ( t tests) and binary ( χ2 /McNemar tests) outcomes. In a study subsample, urinary equol was measured after the consumption of ½ cup (86 g) of cooked whole soybeans twice daily for 3 days. RESULTS: In the intervention group, moderate-to-severe hot flashes decreased by 88% ( P < 0.001) compared with 34% for the control group ( P < 0.001; between-group P < 0.001). At 12 weeks, 50% of completers in the intervention group reported no moderate-to-severe hot flashes at all. Among controls, there was no change in this variable from baseline ( χ2 test, P < 0.001). Neither seasonality nor equol production status was associated with the degree of improvement. The intervention group reported greater reductions in the Menopause-Specific Quality of Life questionnaire vasomotor ( P = 0.004), physical ( P = 0.01), and sexual ( P = 0.03) domains. CONCLUSIONS: A dietary intervention consisting of a plant-based diet, minimizing oils, and daily soybeans significantly reduced the frequency and severity of postmenopausal hot flashes and associated symptoms.

Nordic dietary patterns and cardiometabolic outcomes: a systematic review and meta-analysis of prospective cohort studies and randomised controlled trials.

AIMS/HYPOTHESIS: Nordic dietary patterns that are high in healthy traditional Nordic foods may have a role in the prevention and management of diabetes. To inform the update of the EASD clinical practice guidelines for nutrition therapy, we conducted a systematic review and meta-analysis of Nordic dietary patterns and cardiometabolic outcomes. METHODS: We searched MEDLINE, EMBASE and The Cochrane Library from inception to 9 March 2021. We included prospective cohort studies and RCTs with a follow-up of ≥1 year and ≥3 weeks, respectively. Two independent reviewers extracted relevant data and assessed the risk of bias (Newcastle-Ottawa Scale and Cochrane risk of bias tool). The primary outcome was total CVD incidence in the prospective cohort studies and LDL-cholesterol in the RCTs. Secondary outcomes in the prospective cohort studies were CVD mortality, CHD incidence and mortality, stroke incidence and mortality, and type 2 diabetes incidence; in the RCTs, secondary outcomes were other established lipid targets (non-HDL-cholesterol, apolipoprotein B, HDL-cholesterol, triglycerides), markers of glycaemic control (HbA1c, fasting glucose, fasting insulin), adiposity (body weight, BMI, waist circumference) and inflammation (C-reactive protein), and blood pressure (systolic and diastolic blood pressure). The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of the evidence. RESULTS: We included 15 unique prospective cohort studies (n=1,057,176, with 41,708 cardiovascular events and 13,121 diabetes cases) of people with diabetes for the assessment of cardiovascular outcomes or people without diabetes for the assessment of diabetes incidence, and six RCTs (n=717) in people with one or more risk factor for diabetes. In the prospective cohort studies, higher adherence to Nordic dietary patterns was associated with 'small important' reductions in the primary outcome, total CVD incidence (RR for highest vs lowest adherence: 0.93 [95% CI 0.88, 0.99], p=0.01; substantial heterogeneity: I2=88%, pQ<0.001), and similar or greater reductions in the secondary outcomes of CVD mortality and incidence of CHD, stroke and type 2 diabetes (p<0.05). Inverse dose-response gradients were seen for total CVD incidence, CVD mortality and incidence of CHD, stroke and type 2 diabetes (p<0.05). No studies assessed CHD or stroke mortality. In the RCTs, there were small important reductions in LDL-cholesterol (mean difference [MD] -0.26 mmol/l [95% CI -0.52, -0.00], pMD=0.05; substantial heterogeneity: I2=89%, pQ<0.01), and 'small important' or greater reductions in the secondary outcomes of non-HDL-cholesterol, apolipoprotein B, insulin, body weight, BMI and systolic blood pressure (p<0.05). For the other outcomes there were 'trivial' reductions or no effect. The certainty of the evidence was low for total CVD incidence and LDL-cholesterol; moderate to high for CVD mortality, established lipid targets, adiposity markers, glycaemic control, blood pressure and inflammation; and low for all other outcomes, with evidence being downgraded mainly because of imprecision and inconsistency. CONCLUSIONS/INTERPRETATION: Adherence to Nordic dietary patterns is associated with generally small important reductions in the risk of major CVD outcomes and diabetes, which are supported by similar reductions in LDL-cholesterol and other intermediate cardiometabolic risk factors. The available evidence provides a generally good indication of the likely benefits of Nordic dietary patterns in people with or at risk for diabetes. REGISTRATION: ClinicalTrials.gov NCT04094194. FUNDING: Diabetes and Nutrition Study Group of the EASD Clinical Practice.

Relation of Change or Substitution of Low- and No-Calorie Sweetened Beverages With Cardiometabolic Outcomes: A Systematic Review and Meta-analysis of Prospective Cohort Studies.

BACKGROUND: Adverse associations of low- and no-calorie sweetened beverages (LNCSB) with cardiometabolic outcomes in observational studies may be explained by reverse causality and residual confounding. PURPOSE: To address these limitations we used change analyses of repeated measures of intake and substitution analyses to synthesize the association of LNCSB with cardiometabolic outcomes. DATA SOURCES: MEDLINE, Embase, and the Cochrane Library were searched up to 10 June 2021 for prospective cohort studies with ≥1 year of follow-up duration in adults. STUDY SELECTION: Outcomes included changes in clinical measures of adiposity, risk of overweight/obesity, metabolic syndrome, type 2 diabetes (T2D), cardiovascular disease, and total mortality. DATA EXTRACTION: Two independent reviewers extracted data, assessed study quality, and assessed certainty of evidence using GRADE. Data were pooled with a random-effects model and expressed as mean difference (MD) or risk ratio (RR) and 95% CI. DATA SYNTHESIS: A total of 14 cohorts (416,830 participants) met the eligibility criteria. Increase in LNCSB intake was associated with lower weight (5 cohorts, 130,020 participants; MD -0.008 kg/year [95% CI -0.014, -0.002]). Substitution of LNCSB for sugar-sweetened beverages (SSB) was associated with lower weight (three cohorts, 165,579 participants; MD, -0.12 [-0.14, -0.10,] kg/y) and lower incidence of obesity (OB) (one cohort, 15,765 participants; RR 0.88 [95% CI 0.88, 0.89]), coronary heart disease (six cohorts, 233,676 participants; 0.89 [0.81, 0.98]), cardiovascular disease mortality (one cohort, 118,363 participants; 0.95 [0.90, 0.99]), and total mortality (one cohort, 118,363 participants; 0.96 [0.94, 0.98]) with no adverse associations across other outcomes. Substitution of water for SSB showed lower weight (three cohorts, 165,579 participants; MD -0.10 kg/year [-0.13, -0.06]), lower waist circumference (one cohort, 173 participants; -2.71 cm/year [-4.27, -1.15]) and percent body fat (one cohort, 173 participants; -1.51% per year [-2.61, -0.42]), and lower incidence of OB (one cohort, 15,765 participants; RR 0.85 [0.75, 0.97]) and T2D (three cohorts, 281,855 participants; 0.96 [0.94, 0.98]). Substitution of LNCSB for water showed no adverse associations. LIMITATIONS: The evidence was low to very low certainty owing to downgrades for imprecision, indirectness, and/or inconsistency. CONCLUSIONS: LNCSB were not associated with cardiometabolic harm in analyses that model the exposure as change or substitutions. The available evidence provides some indication that LNCSB in their intended substitution for SSB may be associated with cardiometabolic benefit, comparable with the standard of care, water.

Nutrition for Hospital Workers During a Crisis: Effect of a Plant-Based Dietary Intervention on Cardiometabolic Outcomes and Quality of Life in Healthcare Employees During the COVID-19 Pandemic.

The study tested the effects of a vegan diet on cardiometabolic outcomes and quality of life among healthcare employees during the COVID-19 pandemic. Overweight hospital employees were enrolled and randomly assigned (in a 1:1 ratio) to an intervention group, which was asked to follow a low-fat vegan diet, or a control group, asked to make no diet changes. However, due to COVID-19 disruptions, all participants remained on their usual diets from March to June (12 weeks), creating a de facto control period, and all (n = 12) started the vegan diet with online classes in June, which continued for 12 weeks. Nine participants completed all final assessments. A crossover ANOVA was used for statistical analysis of differences in cardiovascular health during the control period and during the intervention. Despite the ongoing crisis, body weight decreased (treatment effect -5.7 kg [95% CI -9.7 to -1.7]; P = .01); fasting plasma glucose decreased (-11.4 mg/dL [95% CI -18.8 to -4.1]; P = .007); total and LDL-cholesterol decreased (-30.7 mg/dL [95% CI -53.8 to -7.5]; P = .02; and -24.6 mg/dL [-44.8 to -4.3]; P = .02, respectively); diastolic blood pressure decreased (-8.5 mm Hg [95% CI -16.3 to -.7]; P = .03); and quality of life increased (P = .005) during the intervention period, compared with the control period. A vegan diet improved cardiometabolic outcomes and quality of life in healthcare workers at the height of the COVID-19 pandemic.

Changes in Food and Nutrient Intake and Diet Quality on a Low-Fat Vegan Diet Are Associated with Changes in Body Weight, Body Composition, and Insulin Sensitivity in Overweight Adults: A Randomized Clinical Trial.

BACKGROUND: Consuming different food groups and nutrients can have differential effects on body weight, body composition, and insulin sensitivity. OBJECTIVE: The aim was to identify how food group, nutrient intake, and diet quality change relative to usual-diet controls after 16 weeks on a low-fat vegan diet and what associations those changes have with changes in body weight, body composition, and measures of metabolic health. DESIGN: Secondary analysis of a randomized clinical trial conducted between October 2016 and December 2018 in four replications. PARTICIPANTS/SETTING: Participants included in this analysis were 219 healthy, community-based adults in the Washington, DC, area, with a body mass index (BMI) between 28 and 40, who were randomly assigned to either follow a low-fat vegan diet or make no diet changes. INTERVENTION: A low-fat, vegan diet deriving approximately 10% of energy from fat, with weekly classes including dietary instruction, group discussion, and education on the health effects of plant-based nutrition. Control group participants continued their usual diets. MAIN OUTCOME MEASURES: Changes in food group intake, macronutrient and micronutrient intake, and dietary quality as measured by Alternate Healthy Eating Index-2010 (AHEI-2010), analyzed from 3-day diet records, and associations with changes in body weight, body composition, and insulin sensitivity were assessed. STATISTICAL ANALYSES PERFORMED: A repeated-measure analysis of variance model that included the factors group, subject, and time was used to test the between-group differences throughout the 16-week study. Interaction between group and time was calculated for each variable. Within each diet group, paired comparison t tests were calculated to identify significant changes from baseline to 16 weeks. Spearman correlations were calculated for the relationship between changes in food group intake, nutrient intake, AHEI-2010 score, and changes in body weight, body composition, and insulin sensitivity. The relative contribution of food groups and nutrients to weight loss was evaluated using linear regression. RESULTS: Fruit, vegetable, legume, meat alternative, and whole grain intake significantly increased in the vegan group. Intake of meat, fish, and poultry; dairy products; eggs; nuts and seeds; and added fats decreased. Decreased weight was most associated with increased intake of legumes (r = -0.38; P < 0.0001) and decreased intake of total meat, fish, and poultry (r = +0.43; P < 0.0001). Those consuming a low-fat vegan diet also increased their intake of carbohydrates, fiber, and several micronutrients and decreased fat intake. Reduced fat intake was associated with reduced body weight (r = +0.15; P = 0.02) and, after adjustment for changes in BMI and energy intake, with reduced fat mass (r = +0.14; P = 0.04). The intervention group's AHEI-2010 increased by 6.0 points on average, in contrast to no significant change in the control group (treatment effect, +7.2 [95% CI +3.7 to +10.7]; P < 0.001). Increase in AHEI-2010 correlated with reduction in body weight (r = 0.14; P = 0.04), fat mass (r = -0.14; P = 0.03), and insulin resistance as measured by the Homeostasis Model Assessment (HOMA-IR; r = -0.17; P = 0.02), after adjustment for changes in energy intake. CONCLUSIONS: When compared with participants' usual diets, intake of plant foods increased, and consumption of animal foods, nuts and seeds, and added fats decreased on a low-fat vegan diet. Increased legume intake was the best single food group predictor of weight loss. Diet quality as measured by AHEI-2010 improved on the low-fat vegan diet, which was associated with improvements in weight and metabolic outcomes. These data suggest that increasing low-fat plant foods and minimizing high-fat and animal foods is associated with decreased body weight and fat loss, and that a low-fat vegan diet can improve measures of diet quality and metabolic health.

Association of Low- and No-Calorie Sweetened Beverages as a Replacement for Sugar-Sweetened Beverages With Body Weight and Cardiometabolic Risk: A Systematic Review and Meta-analysis.

Importance: There are concerns that low- and no-calorie sweetened beverages (LNCSBs) do not have established benefits, with major dietary guidelines recommending the use of water and not LNCSBs to replace sugar-sweetened beverages (SSBs). Whether LNCSB as a substitute can yield similar improvements in cardiometabolic risk factors vs water in their intended substitution for SSBs is unclear. Objective: To assess the association of LNCSBs (using 3 prespecified substitutions of LNCSBs for SSBs, water for SSBs, and LNCSBs for water) with body weight and cardiometabolic risk factors in adults with and without diabetes. Data Sources: Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched from inception through December 26, 2021. Study Selection: Randomized clinical trials (RCTs) with at least 2 weeks of interventions comparing LNCSBs, SSBs, and/or water were included. Data Extraction and Synthesis: Data were extracted and risk of bias was assessed by 2 independent reviewers. A network meta-analysis was performed with data expressed as mean difference (MD) or standardized mean difference (SMD) with 95% CIs. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to assess the certainty of the evidence. Main Outcomes and Measures: The primary outcome was body weight. Secondary outcomes were other measures of adiposity, glycemic control, blood lipids, blood pressure, measures of nonalcoholic fatty liver disease, and uric acid. Results: A total of 17 RCTs with 24 trial comparisons were included, involving 1733 adults (mean [SD] age, 33.1 [6.6] years; 1341 women [77.4%]) with overweight or obesity who were at risk for or had diabetes. Overall, LNCSBs were a substitute for SSBs in 12 RCTs (n = 601 participants), water was a substitute for SSBs in 3 RCTs (n = 429), and LNCSBs were a substitute for water in 9 RCTs (n = 974). Substitution of LNCSBs for SSBs was associated with reduced body weight (MD, -1.06 kg; 95% CI, -1.71 to -0.41 kg), body mass index (MD, -0.32; 95% CI, -0.58 to -0.07), percentage of body fat (MD, -0.60%; 95% CI, -1.03% to -0.18%), and intrahepatocellular lipid (SMD, -0.42; 95% CI, -0.70 to -0.14). Substituting water for SSBs was not associated with any outcome. There was also no association found between substituting LNCSBs for water with any outcome except glycated hemoglobin A1c (MD, 0.21%; 95% CI, 0.02% to 0.40%) and systolic blood pressure (MD, -2.63 mm Hg; 95% CI, -4.71 to -0.55 mm Hg). The certainty of the evidence was moderate (substitution of LNCSBs for SSBs) and low (substitutions of water for SSBs and LNCSBs for water) for body weight and was generally moderate for all other outcomes across all substitutions. Conclusions and Relevance: This systematic review and meta-analysis found that using LNCSBs as an intended substitute for SSBs was associated with small improvements in body weight and cardiometabolic risk factors without evidence of harm and had a similar direction of benefit as water substitution. The evidence supports the use of LNCSBs as an alternative replacement strategy for SSBs over the moderate term in adults with overweight or obesity who are at risk for or have diabetes.