Estimates of resting energy expenditure and total energy expenditure using predictive equations in adults with overweight and obesity: a systematic review with meta-analysis.

CONTEXT: Energy expenditure predictive equations can generate inaccurate estimates for overweight or obese individuals. OBJECTIVE: The objective of this review was to determine which predictive equations for resting energy expenditure (REE) and total energy expenditure (TEE) have the lowest bias and the highest precision in adults with overweight and obesity. DATA SOURCES: Searches were performed in January 2022 in MEDLINE, Web of Science, Scopus, CENTRAL, and the gray literature databases. DATA EXTRACTION: Meta-analyses were performed with equations included in more than 1 study. The DerSimonian and Laird random-effects model and the I2 statistic were used to quantify heterogeneity in the quantitative analyses. The Egger test was performed to assess potential publication biases, and metaregressions were conducted to explore the heterogeneity. Findings were presented separated by participants' body mass index classification (overweight and obesity). DATA ANALYSIS: Sixty-one studies were included. The FAO/WHO/UNU (1985) equation, which uses only body weight in its formula, showed the lowest bias in estimating REE (mean difference [MD] = 8.97 kcal; 95% CI = -26.99; 44.94). In the subgroup analysis for individuals with obesity, the Lazzer (2007) equation showed the lowest bias (MD = 4.70 kcal; 95% CI = -95.45; 104.86). The Harris-Benedict equation (1919) showed the highest precision values for individuals with overweight (60.65%) and for individuals with obesity (62.54%). Equations with body composition data showed the highest biases. The equation proposed by the Institute of Medicine (2005) showed the lowest bias (MD = -2.52 kcal; 95% CI = -125.94; 120.90) in estimating the TEE. Most analyses showed high heterogeneity (I2 > 90%). There was no evidence of publication bias. CONCLUSION: For individuals with overweight, the FAO/WHO/UNU (1985) and the Harris-Benedict equations (1919) showed the lowest bias and the highest precision in predicting the REE, respectively. For individuals with obesity, the Harris-Benedict equation (1919) showed the highest precision and the Lazzer equation (2007) showed the lowest bias. More studies are needed on predictive equations to estimate the TEE. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42021262969.

Curcumin or combined curcuminoids are effective in lowering the fasting blood glucose concentrations of individuals with dysglycemia: Systematic review and meta-analysis of randomized controlled trials.

Curcuminoids have received considerable attention as therapeutical adjuvants in the treatment of dysglycemia. The purpose of this meta-analysis was to evaluate whether the supplementation of turmeric extract, curcuminoids and/or isolated curcumin is more effective than placebo in decreasing fasting blood glucose (FBG) in adults. MEDLINE, CENTRAL, ScienceDirect and gray literature databases were searched. Randomized controlled trials with the following criteria were included: (1) studied individuals older than 18 years, supplemented with curcumin, curcuminoids and/or turmeric extract (2) had a follow-up ≥4 weeks (3) used a placebo group. Titles and abstracts were screened and potentially eligible articles were retrieved. The primary outcome was FBG. The secondary outcomes were HbA1c and HOMA-IR. Eleven studies were included. In the overall analysis, turmeric, curcuminoids and curcumin supplementation led to a decrease in FBG (-8.88, 95% CI: [-5.04 to -2.72] mg/dL, p = 0.005). Supplementation of curcuminoids and/or curcumin decreased the concentrations of HbA1c (-0.54, 95% CI: [-1.09 to -0.002] %, p = 0.049) but were not able to decrease HOMA-IR (-1.26, 95% CI: [-3.71 to -1.19], p = 0.31). Sensitivity analyses revealed that baseline FBG was an important covariate. Heterogeneity was high in the overall analyses and there was evidence of publication bias. Supplementation of isolated curcumin or combined curcuminoids were both effective in lowering the FBG concentrations of individuals with some degree of dysglycemia, but not in non-diabetic individuals. Isolated curcumin lead to significant decreases of the HbA1c compared to placebo.

Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials.

The role of very-low-carbohydrate ketogenic diets (VLCKD) in the long-term management of obesity is not well established. The present meta-analysis aimed to investigate whether individuals assigned to a VLCKD (i.e. a diet with no more than 50 g carbohydrates/d) achieve better long-term body weight and cardiovascular risk factor management when compared with individuals assigned to a conventional low-fat diet (LFD; i.e. a restricted-energy diet with less than 30% of energy from fat). Through August 2012, MEDLINE, CENTRAL, ScienceDirect,Scopus, LILACS, SciELO, ClinicalTrials.gov and grey literature databases were searched, using no date or language restrictions, for randomised controlled trials that assigned adults to a VLCKD or a LFD, with 12 months or more of follow-up. The primary outcome was bodyweight. The secondary outcomes were TAG, HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), systolic and diastolic blood pressure,glucose, insulin, HbA1c and C-reactive protein levels. A total of thirteen studies met the inclusion/exclusion criteria. In the overall analysis,five outcomes revealed significant results. Individuals assigned to a VLCKD showed decreased body weight (weighted mean difference -0·91 (95% CI -1·65, -0·17) kg, 1415 patients), TAG (weighted mean difference -0·18 (95% CI -0·27, -0·08) mmol/l, 1258 patients)and diastolic blood pressure (weighted mean difference -1·43 (95% CI -2·49, -0·37) mmHg, 1298 patients) while increased HDL-C(weighted mean difference 0·09 (95% CI 0·06, 0·12) mmol/l, 1257 patients) and LDL-C (weighted mean difference 0·12 (95% CI 0·04,0·2) mmol/l, 1255 patients). Individuals assigned to a VLCKD achieve a greater weight loss than those assigned to a LFD in the longterm; hence, a VLCKD may be an alternative tool against obesity.