scholarly journals Restricting Calories on Low-Carbohydrate vs Low-fat Diets for Weight Loss: A Systematic Review and Meta-Analysis

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1609-1609
Author(s):  
Anthony Basile ◽  
Michael Renner ◽  
Jessica Scillian ◽  
Karen Sweazea
Keyword(s):  
Systematic Review ◽  
Weight Loss ◽  
Mass Loss ◽  
Fat Mass ◽  
Meta Analysis ◽  
Low Fat ◽  
Fat Loss ◽  
Low Carbohydrate Diet ◽  
Low Carbohydrate ◽  
Fat Mass Loss

Abstract Objectives As the never-ending macronutrient debate for weight loss continues, conflicting evidence persist. Per the carbohydrate-insulin hypothesis, a low-carbohydrate diet (LC) should produce a greater weight/fat loss compared to a low-fat/calorie diet (LF) by releasing less of the anabolic hormone insulin. However, from a ‘calories in, calories out’ perspective, does restricting calories on a LC diet produce a greater weight/fat loss compared to a LF diet? Methods A systematic review and meta-analysis of LC vs LF trials for weight loss was conducted and data were collected from 53 studies. Weight loss data were converted to kcals (1 kg = 3500 kcals) and a ratio was produced for each individual diet (ID-Ratio: weight loss in kcals/restricted dietary kcals) where a ratio of 1 indicates that one dietary kcal restriction equals one kcal of weight loss. Next, to compare the two diets, a comparison ratio (DC-Ratio: LC ID-Ration/LF ID-Ratio) was produced where a ratio greater than 1 indicates greater weight loss per dietary calorie restricted with LC diet. These calculations were repeated for body fat loss for full duration (n = 30 trials) and time of greatest weight loss (TGWL; Weight Loss: n = 19 trials; Fat Mass Loss: n = 4 trials). Results LC diets produced a greater weight loss (Full Duration: 6.10 kg vs 4.86 kg; n = 53 trials; P = 0.024; TGWL: 6.29 kg vs 4.34 kg; n = 19 trials; P = 0.024), however no difference was found for the amount of restricted calories or fat mass loss for either duration. No difference was found for the LC and LF ID-Ratios for weight or fat mass loss for either duration. The mean weight loss DC-Ratio was greater than 1 (Full Duration Mean: 1.61, SD: 1.71, n = 53 studies, P = 0.004; TGWL Mean: 1.74, SD: 1.0, n = 19 trails, P = 0.010) indicating a greater weight loss per calorie restricted with a LC diet. However, the fat loss DC-Ratio was not different from 1 (Full Duration Mean: 1.74, SD: 1.09, n = 30 trials, P = 0.552; TGWL Mean: 1.25, SD: 0.53, n = 4 trials, P = 0.428). Conclusions From a ‘calories in, calories out’ perspective, restricting calories on a LC diet produced a greater weight loss for the full duration of the trails and at the time of greatest weight loss compared to a LF diet. As no effect was seen on LC diets and fat mass loss, these results do not support the carbohydrate-insulin hypothesis of obesity. Funding Sources School of Life Sciences, Arizona State University.

scholarly journals Effects of Ad Libitum Low Carbohydrate Versus Low Fat Diets on Body Weight and Fat Mass

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 658-658
Author(s):  
Alex Schick ◽  
James Boring ◽  
Amber Courville ◽  
Isabelle Gallagher ◽  
Juen Guo ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Body Fat ◽  
Fat Mass ◽  
Kidney Diseases ◽  
Primary Study ◽  
Low Fat ◽  
Fat Loss ◽  
Low Carbohydrate ◽  
Ad Libitum

Abstract Objectives To describe the effects of ad libitum low-fat (LF) and low-carbohydrate (LC) diets on body weight and fat mass. Methods Sixteen adults without diabetes spent 29 continuous days residing at the Metabolic Clinical Research Unit of the NIH Clinical Center where they were fed ad libitum either an animal-based, LC diet (75% fat, 10% carbohydrates, 15% protein) or a plant-based, LF diet (75% carbohydrates, 10% fat, 15% protein). Participants were randomly assigned to one diet for the first phase of the study (14 days), after which they were switched to the other diet for the remainder of the study. Participants were given three meals daily and were provided with additional snacks amounting to 200% of their daily energy requirements as determined by their resting energy expenditure multiplied by 1.6. Subjects were told that this was not a weight loss study and were not informed about the primary study aim. They were instructed to eat as much or as little as they desired. Total body weight and fat mass were measured using a calibrated scale and dual-energy X-ray absorptiometry, respectively. Subjects were blinded to their data and wore loose-fitting scrubs to avoid any feedback regarding changes in the fit of their clothing. Results Subjects included 7 women and 9 men, with an age of (mean ± SE) 29 ± 1.7 years and BMI of 27.5 ± 1.5 at baseline. Participants lost weight on both diets, with the LC diet resulting in 1.34 ± 0.31 kg of weight loss (P = 0.0006) and the LF diet resulting in 1.09 ± 0.31 kg of weight loss (P = 0.003) which was not significantly different from the LC diet (P = 0.58). However, participants lost 0.6 ± 0.17 kg of body fat on the LF diet (P = 0.002) but the LC diet did not result in significant body fat loss (0.04 ± 0.17 kg; P = 0.8) and the difference in body fat loss between the diets was statistically significant (P = 0.03). Conclusions While participants lost similar amounts of weight on both diets, only the LF diet led to significant body fat loss. Early weight loss with a LC diet does not necessarily reflect a similar state of negative energy balance as compared with a LF diet. Funding Sources Intramural Research Program of the National Institutes of Diabetes and Digestive and Kidney Diseases.

Abstract P268: Weight Change is a Poor Predictor of Change in Body Fatness in Cardiac Rehabilitation Patients

Circulation ◽  
2012 ◽  
Vol 125 (suppl_10) ◽  
Author(s):  
Quinn R Pack ◽  
Randal Thomas ◽  
Ray Squires ◽  
Lezlie Johnson ◽  
Virend Somers ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Composition ◽  
Waist Circumference ◽  
Positive Predictive Value ◽  
Mass Loss ◽  
Body Fat ◽  
Fat Mass ◽  
Predictive Value ◽  
Fat Loss ◽  
Fat Mass Loss

Introduction : Obesity is a common risk factor in cardiac rehabilitation (CR), yet many CR patients do not realize significant weight loss, despite engaging in regular exercise training while in CR. Hypothesis : We hypothesized that standard CR would demonstrate favorable body composition (BC) changes even in the absence of weight loss and sought to measure the performance characteristics of weight loss to predict BC changes. Methods : We included consecutive patients enrolled in early outpatient CR who underwent air displacement plethysmography with measurements of height, weight, and waist circumference at initiation and completion of CR. We calculated the accuracy of weight loss to identify significant improvements in BC. Results : Data from 112 patients were available for analysis; mean age 60±12 yr., 76% male, mean body mass index (BMI) 30.2±5.3 kg/m 2 . The indication for CR was myocardial infarction (n=33), percutaneous coronary intervention (n=29), coronary artery bypass or valve surgery (n=45), and heart transplant (n=5). Repeat testing occurred after a median of 81 days and 21 phase II CR sessions. There was no change in BMI (-0.53±1.3 kg/m 2 , p=0.43) and weight (-1.6±4.0 kg, p=0.51). Fat mass showed a borderline significant decrease of 2.9±3.9 kg (p=0.08). However, BC improved significantly as measured by body fat % (-2.5±3.2%, p=0.03) and waist circumference (-4.6±5.2 cm; p=0.01). There was a correlation between weight loss and fat mass loss (r=0.85, p=0.0001, positive predictive value=0.94), and % fat change (r=0.67, p=0.0001, positive predictive value=0.91). See table 1. However, the negative predictive value to detect no fat change for patients who did not lose weight was low (0.49, when assessed by % body fat loss, and 0.57, when assessed by fat mass loss). Among patients who did not lose weight, 29 (51%) had a greater than 1% body fat loss. Conclusions : The diagnostic performance of weight change to predict favorable BC changes is poor and highlights the potential utility of BC measurements in the CR setting. Table. Diagnostic Characteristics of Weight Loss as a Predictor of Improvements in Body Composition Weight Loss (kg) Body Fat % Loss ≤ 1% Fat Mass Loss (kg) > 1kg > 1% ≤ 1kg > 1kg 49 5 51 3 ≤ 1kg or gain 29 28 25 33 Sensitivity 0.63 0.67 Specificity 0.85 0.92 PPV * 0.91 0.94 NPV ** 0.49 0.57 * PPV = Positive Predictive Valve, ** NPV = Negative Predictive Value

scholarly journals The Effect of Low-Fat and Low-Carbohydrate Diets on Weight Loss and Lipid Levels: A Systematic Review and Meta-Analysis

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3774
Author(s):  
Shreya Chawla ◽  
Fernanda Tessarolo Silva ◽  
Sofia Amaral Medeiros ◽  
Rania A. Mekary ◽  
Dina Radenkovic
Keyword(s):  
Weight Loss ◽  
Total Cholesterol ◽  
Meta Analysis ◽  
Density Lipoprotein ◽  
Lipoprotein Cholesterol ◽  
Average Weight ◽  
Low Fat ◽  
Low Carbohydrate Diet ◽  
Low Carbohydrate ◽  
Fat Diets

Background: The rise in obesity has emphasised a focus on lifestyle and dietary habits. We aimed to address the debate between low-carbohydrate and low-fat diets and compare their effects on body weight, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), total cholesterol, and triglycerides in an adult population. Method: Medline and Web of Science were searched for randomised controlled trials (RCTs) comparing low-fat and low-carbohydrate diets up to September 2019. Three independent reviewers extracted data. Risk of bias was assessed using the Cochrane tool. The meta-analysis was stratified by follow-up time using the random-effects models. Results: This meta-analysis of 38 studies assessed a total of 6499 adults. At 6–12 months, pooled analyses of mean differences of low-carbohydrate vs. low-fat diets favoured the low-carbohydrate diet for average weight change (mean difference −1.30 kg; 95% CI −2.02 to −0.57), HDL (0.05 mmol/L; 95% CI 0.03 to 0.08), and triglycerides (TG) (−0.10 mmol/L; −0.16 to −0.04), and favoured the low-fat diet for LDL (0.07 mmol/L; 95% CI 0.02 to 0.12) and total cholesterol (0.10 mmol/L; 95% CI 0.02 to 0.18). Conclusion and Relevance: This meta-analysis suggests that low-carbohydrate diets are effective at improving weight loss, HDL and TG lipid profiles. However, this must be balanced with potential consequences of raised LDL and total cholesterol in the long-term.

scholarly journals Efficacy and safety of low and very low carbohydrate diets for type 2 diabetes remission: systematic review and meta-analysis of published and unpublished randomized trial data

BMJ ◽  
2021 ◽  
pp. m4743
Author(s):  
Joshua Z Goldenberg ◽  
Andrew Day ◽  
Grant D Brinkworth ◽  
Junko Sato ◽  
Satoru Yamada ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Systematic Review ◽  
Type 2 Diabetes ◽  
Weight Loss ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Low Carbohydrate ◽  
Remission Of Diabetes

Abstract Objective To determine the efficacy and safety of low carbohydrate diets (LCDs) and very low carbohydrate diets (VLCDs) for people with type 2 diabetes. Design Systematic review and meta-analysis. Data sources Searches of CENTRAL, Medline, Embase, CINAHL, CAB, and grey literature sources from inception to 25 August 2020. Study selection Randomized clinical trials evaluating LCDs (<130 g/day or <26% of a 2000 kcal/day diet) and VLCDs (<10% calories from carbohydrates) for at least 12 weeks in adults with type 2 diabetes were eligible. Data extraction Primary outcomes were remission of diabetes (HbA 1c <6.5% or fasting glucose <7.0 mmol/L, with or without the use of diabetes medication), weight loss, HbA 1c , fasting glucose, and adverse events. Secondary outcomes included health related quality of life and biochemical laboratory data. All articles and outcomes were independently screened, extracted, and assessed for risk of bias and GRADE certainty of evidence at six and 12 month follow-up. Risk estimates and 95% confidence intervals were calculated using random effects meta-analysis. Outcomes were assessed according to a priori determined minimal important differences to determine clinical importance, and heterogeneity was investigated on the basis of risk of bias and seven a priori subgroups. Any subgroup effects with a statistically significant test of interaction were subjected to a five point credibility checklist. Results Searches identified 14 759 citations yielding 23 trials (1357 participants), and 40.6% of outcomes were judged to be at low risk of bias. At six months, compared with control diets, LCDs achieved higher rates of diabetes remission (defined as HbA 1c <6.5%) (76/133 (57%) v 41/131 (31%); risk difference 0.32, 95% confidence interval 0.17 to 0.47; 8 studies, n=264, I 2 =58%). Conversely, smaller, non-significant effect sizes occurred when a remission definition of HbA 1c <6.5% without medication was used. Subgroup assessments determined as meeting credibility criteria indicated that remission with LCDs markedly decreased in studies that included patients using insulin. At 12 months, data on remission were sparse, ranging from a small effect to a trivial increased risk of diabetes. Large clinically important improvements were seen in weight loss, triglycerides, and insulin sensitivity at six months, which diminished at 12 months. On the basis of subgroup assessments deemed credible, VLCDs were less effective than less restrictive LCDs for weight loss at six months. However, this effect was explained by diet adherence. That is, among highly adherent patients on VLCDs, a clinically important reduction in weight was seen compared with studies with less adherent patients on VLCDs. Participants experienced no significant difference in quality of life at six months but did experience clinically important, but not statistically significant, worsening of quality of life and low density lipoprotein cholesterol at 12 months. Otherwise, no significant or clinically important between group differences were found in terms of adverse events or blood lipids at six and 12 months. Conclusions On the basis of moderate to low certainty evidence, patients adhering to an LCD for six months may experience remission of diabetes without adverse consequences. Limitations include continued debate around what constitutes remission of diabetes, as well as the efficacy, safety, and dietary satisfaction of longer term LCDs. Systematic review registration PROSPERO CRD42020161795.

THE EFFECTS OF LOW-CARBOHYDRATE VERSUS LOW-FAT DIETS IN OBESE/OVERWEIGHT ADULTS: ONE-YEAR FOLLOW-UP OF A RANDOMIZED TRIAL

2021 ◽  
pp. 27-29
Author(s):  
Maitri Hathi ◽  
Sudesh Kumar
Keyword(s):  
Weight Loss ◽  
Randomized Trial ◽  
Caloric Intake ◽  
Low Fat ◽  
Obese Adults ◽  
Low Carbohydrate Diet ◽  
Low Carbohydrate ◽  
One Year ◽  
The One

Aprevious paper reported the six month comparison of weight loss in overweight and/or obese adults randomly assigned to either a VLCK-diet or LF-diet. To review the one year outcomes between these diets 1year follow-up of a randomized trial on 113 overweight/obese adults with a BMI>25 kg/m2; with no abnormalities were randomly selected. Participants who selected VLCK diet received counseling to restrict carbohydrate intake to <30 gram per day and those who selected LF diet received counseling to restrict caloric intake by 500 calories per day with <30% of calories from fat. Changes in weight, Body Mass Index, Body Fat, and Waist Circumference were measured at intervals of rst, third, sixth and twelfth month of participants who completed the one-year follow-up. Participants on the very-low-carbohydrate diet had lost more weight loss than participants on the conventional low-fat diet at 3months, 6month and but the difference at 12months were signicant. Study conclude that participants on a VLCK-diet had more favorable overall outcomes at 1year than did those on a conventional LF-diet. Weight loss was similar between groups.

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