Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials.

There is no research on the comparative effects of nutraceuticals on weight loss in adults with overweight or obesity. This study aimed at quantifying and ranking the effects of different nutraceuticals on weight loss. We searched PubMed, Scopus, and Web of Science to November 2022. We included randomized trials evaluating the comparative effects of two or more nutraceuticals, or compared a nutraceutical against a placebo for weight loss in adults with overweight or obesity. We conducted random-effects network meta-analysis with a Frequentist framework to estimate mean difference [MD] and 95% confidence interval [CI] of the effect of nutraceuticals on weight loss. One hundred and eleven RCTs with 6171 participants that investigated the effects of 18 nutraceuticals on body weight were eligible. In the main analysis incorporating all trials, there was high certainty of evidence for supplementation of spirulina (MD: -1.77 kg, 95% CI: -2.77, -0.78) and moderate certainty of evidence that supplementation of curcumin (MD: -0.82 kg, 95% CI: -1.33, -0.30), psyllium (MD: -3.70 kg, 95% CI: -5.18, -2.22), chitosan (MD: -1.70 kg, 95% CI: -2.62, -0.78), and Nigella sativa (MD: -2.09 kg, 95%CI: -2.92, -1.26) could result in a small improvement in body weight. Supplementations with green tea (MD: -1.25 kg, 95%CI: -1.68, -0.82) and glucomannan (MD: -1.36 kg, 95%CI: -2.17, -0.54) demonstrated small weight loss, also the certainty of evidence was rated low. Based on our findings, supplementations with nutraceuticals can result in a small weight loss in adults with overweight or obesity.

Association of plant-based dietary patterns in first trimester of pregnancy with gestational weight gain: results from a prospective birth cohort.

BACKGROUND/OBJECTIVES: Plant-based dietary patterns are becoming more popular worldwide. We aimed to examine the relationship between plant-based dietary patterns and the risk of inadequate or excessive gestational weight gain (GWG) in Iranian pregnant women. METHODS: We prospectively followed 657 pregnant women in Iran. Adherence to the plant-based diet, represented by plant-based (PDI), healthy (hPDI) and unhealthy plant-based (uPDI) dietary indexes was evaluated by applying a 90-item food frequency questionnaire during the first trimester of pregnancy. Multivariable-adjusted Cox proportional-hazards regression model was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs) across quartiles of plant-based diet scores. RESULTS: Over 25,562 person-weeks of follow-up, we documented 106 and 294 participants with inadequate and excessive GWG, respectively. We found a strong inverse association between adherence to the PDI and inadequate GWG after adjustment for demographic and confounding variables. Women in the highest quartile of the PDI had 50% lower risk of inadequate GWG than those in the lowest quartile (adjusted HR: 0.50; 95%CI 0.29, 0.89; P = 0.02). No significant association was found between hPDI and uPDI and inadequate GWG. There was no association between PDI, hPDI, and uPDI and the risk of excessive GWG. CONCLUSIONS: Greater adherence to a plant-based diet during the first trimester of pregnancy may be associated with a lower risk of inadequate GWG. This finding needs to be confirmed in larger cohort studies, considering other pregnancy outcomes such as birth weight and the potential changes across the trimester in terms of food types and quantity.

The association between meal-based diet quality index-international (DQI-I) with obesity in adults.

BACKGROUND AND OBJECTIVE: Due to the growing global trend of obesity, it is necessary to study the diet quality as a modifiable factor to reduce the dangerous consequences of obesity. Therefore, the aim of this study was to evaluate the association between meal-based diet quality index-international (DQI-I) with obesity in adults. METHODS: This cross-sectional study was performed on 850 men and women in Tehran (aged 20-59 y). Dietary intakes were assessed using three 24-h dietary recalls. Meal-based Diet quality was assessed based on the construction of DQI-I. The total DQI-I score ranged from 0 to 100, with higher scores denoting better diet quality. Multiple linear regression analysis was used to examine the association of DQI-I and BMI in each meal and Logistic regression analysis was used to examine the association of DQI-I and obesity in each meal. RESULTS: The mean (± SD) of age, body mass index (BMI), waist circumference (WC) and waist to hip ratio (WHR) were 42.35(± 10.90) years, 27.32(± 5.61) kg/m2, 89.09 (± 12.04) cm and 0.86 (± 0.11), respectively. In none of the meals, after adjusting for confounders, no significant difference in BMI was observed in the both women and men groups. After controlling of confounders, there was not any relationship between meal-based DQI-I and BMI resulted from multiple linear regression analysis also there was not any significant association between meal-based DQI-I and obesity resulted from Logistic regression analysis. CONCLUSION: In this study, we did not find any significant association between meal-specified DQI with obesity. To reach the better evaluation, more prospective studies with large sample size are needed.

Anthropometric and adiposity indicators and risk of type 2 diabetes: systematic review and dose-response meta-analysis of cohort studies.

OBJECTIVE: To present a comprehensive review of the association between measures of body weight, waist, and fat, and different ratios of these measures, and the risk of type 2 diabetes. DESIGN: Systematic review and dose-response meta-analysis of cohort studies. DATA SOURCES: PubMed, Scopus, and Web of Science up to 1 May 2021. REVIEW METHODS: Cohort studies looking at the association between general or central adiposity and body fat content and the risk of type 2 diabetes in the general adult population were included. Two of the authors extracted the data in duplicate. Random effects dose-response meta-analyses were performed to estimate the degree of the associations. Curvilinear associations were modelled with a one stage weighted mixed effects meta-analysis. RESULTS: 216 cohort studies with 2.3 million individuals with type 2 diabetes among 26 million participants were identified. Relative risks were 1.72 (95% confidence interval 1.65 to 1.81; n=182 studies) for an increase in body mass index of 5 units, 1.61 (1.52 to 1.70; n=78) for a 10 cm larger waist circumference, 1.63 (1.50 to 1.78; n=34) for an increase in waist-to-hip ratio of 0.1 units, 1.73 (1.51 to 1.98; n=25) for an increase in waist-to-height ratio of 0.1 units, 1.42 (1.27 to 1.58; n=9) for an increase in visceral adiposity index of 1 unit, 2.05 (1.41 to 2.98; n=6) for a 10% higher percentage body fat, 1.09 (1.05 to 1.13, n=5) for an increase in body shape index of 0.005 units, 2.55 (1.59 to 4.10, n=4) for a 10% higher body adiposity index, and 1.11 (0.98 to 1.27; n=14) for a 10 cm larger hip circumference. A strong positive linear association was found between body mass index and the risk of type 2 diabetes. Positive linear or monotonic associations were also found in all regions and ethnicities, without marked deviation from linearity at a specific cut-off value. Indices of central fatness, independent of overall adiposity, also had positive linear or monotonic associations with the risk of type 2 diabetes. Positive linear or monotonic associations were also found for total and visceral fat mass, although the number of studies was small. CONCLUSIONS: A higher body mass index was associated with a greater risk of developing type 2 diabetes. A larger waist circumference, independent of overall adiposity, was strongly and linearly associated with the risk of type 2 diabetes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42021255338.

The joint association of serum vitamin D status and cardiorespiratory fitness with obesity and metabolic syndrome in Tehranian adults.

We aimed to assess the individual and joint association of serum vitamin D and cardiorespiratory fitness (CRF) with obesity and metabolic syndrome (MetSyn). In this cross-sectional study 270 adults with an age range of 18 years and older were recruited from health centers from five districts in Tehran, Iran. CRF was assessed with Bruce protocol. MetSyn was defined based on International Diabetes Federation 2009. The odds ratio (OR) and 95 % confidence interval (CI) of obesity and MetSyn across tertiles of serum vitamin D and CRF were estimated with control for confounders. The results indicated that neither 25(OH)D nor 1,25(OH)D was associated with obesity and MetSyn. There was a strong inverse association between CRF and general (P-trend < 0.001) and abdominal adiposity (P-trend: 0.001). The joint association of vitamin D and CRF indicated that the inverse association of CRF with obesity was stronger in those with high serum vitamin D than those with low serum vitamin D and this joint association remained after considering age and diet quality. There was a significant inverse association for those with low serum 25(OH)D and high CRF (OR: 0.12, 95 % CI: 0.04-0.81; P = 0.02) compared to those with low serum 25(OH)D and low CRF in the crude model. Also, the OR of general obesity was 0.17 (95 % CI: 0.02-0.79; P = 0.03) for those with high CRF and low serum 1,25(OH)D compare with the reference group. Our findings indicated a strong inverse association between CRF and obesity, especially in those with high serum vitamin D.

Dietary inflammatory index (DII) may be associated with hypertriglyceridemia waist circumference phenotype in overweight and obese Iranian women: a cross sectional study.

OBJECTIVE: Recent studies have shown that increased dietary inflammatory index (DII) score or consumption of pro-inflammatory foods can lead to increased waist circumference (WC) as well as triglyceride (TG) concentrations in obese people. The purpose of this study is to examine the association between DII and hypertriglyceridemic waist circumference phenotype (HTGWCP) in women with overweight and obesity. RESULTS: There was a positive significant correlation between DII and HTGWCPs. In other words, with an increase in DII score or higher consumption of pro-inflammatory foods, the odds of having abnormal phenotypes including; enlarged waist normal TG (EWNT) (OR = 2.85, 95% CI 1.02 to 7.98, P for trend = 0.04), normal waist enlarged TG (NWET) (OR = 5.85, 95% CI 1.1 to 31.11, P for trend = 0.03) and enlarged waist enlarged TG (EWET) (OR = 3.13, 95% CI 0.95 to 10.27, P for trend = 0.05) increase compared to normal waist normal TG (NWNT) phenotype. In conclusion; increasing DII scores can increase abnormal phenotypes and therefore may increase WC and TG levels in overweight and obese women.