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 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.

Abstract MP63: Randomized Trials of Low-Fat vs. Other Diet Interventions on Weight Loss: A Meta-Analysis

Circulation ◽  
2014 ◽  
Vol 129 (suppl_1) ◽  
Author(s):  
Deirdre K Tobias ◽  
Mu Chen ◽  
Walter Willett ◽  
Frank B Hu
Keyword(s):  
Weight Loss ◽  
Randomized Trials ◽  
Dietary Intervention ◽  
Meta Analysis ◽  
Dietary Interventions ◽  
Low Fat ◽  
Intervention Intensity ◽  
Low Carbohydrate ◽  
Fat Diets

Introduction: The effectiveness of low-fat diets for weight loss has been debated for decades. Dozens of randomized control trials (RCTs) have assessed whether decreasing the intake of total fat leads to weight loss, giving mixed results. Hypothesis: We hypothesized that low-fat dietary interventions do not lead to greater weight loss when comparator diet intervention intensity is considered. Methods: We conducted a systematic review and meta-analysis. RCTs were included if they compared a low-fat dietary intervention to any control diet with at least 1 year of follow-up. We estimated the combined fixed effect inverse variance weighted mean difference of low-fat vs. comparison diets. Several a priori stratified analyses were considered to explore heterogeneity. Results: Fifty studies met inclusion criteria, reporting 1-10 years of follow-up on 70,054 participants. Overall, low-fat dietary interventions resulted in 0.51kg greater weight loss compared to other diets (95% CI = -0.62, -0.40, p<0.001; I2 = 83%). However, when trials where greater attention was given to the low-fat group were excluded, comparator diets led to greater weight loss than low-fat diets (n=30; WMD=0.87, 95% CI=0.56, 1.17, p<0.001). Similarly, when the type of comparator diet was considered, low-fat diets were only beneficial compared to control groups who were simply asked to maintain their usual diet (n=18; WMD = -1.03, 95% CI = -1.18, -0.88, p<0.001). When equal attention was given to intervention groups, low-carbohydrate diets (n=15; WMD = 1.13kg, 95% CI = 0.53, 1.73, p<0.001) and other “healthy” diets without a low-fat component (n=20; WMD = 0.77kg, 95% CI = 0.42, 1.13, p<0.001) led to greater weight loss than low-fat diets. Comparison diets, irrespective of type, were associated with 1.30kg greater weight loss than low-fat diets when the interventions were intended to be isocaloric (n=19; 95% CI = 0.92, 1.69, p<0.001). Conclusions: Low-fat dietary interventions are not more effective than other diets for weight loss when differences in intervention intensity between treatment groups are considered. Rather, evidence from long-term (>=1 year) randomized trials indicates low-carbohydrate or other healthful dietary pattern interventions without a low-fat focus may be more effective for weight loss than low-fat dietary interventions. Further evidence is needed to establish the role of these interventions in longer-term weight loss and weight maintenance.

scholarly journals Effects of macronutrient intake in obesity: a meta-analysis of low-carbohydrate and low-fat diets on markers of the metabolic syndrome

2020 ◽  
Author(s):  
Anouk E M Willems ◽  
Martina Sura–de Jong ◽  
André P van Beek ◽  
Esther Nederhof ◽  
Gertjan van Dijk
Keyword(s):  
Metabolic Syndrome ◽  
Weight Loss ◽  
Meta Analysis ◽  
Caloric Intake ◽  
Macronutrient Intake ◽  
Fat Intake ◽  
Low Fat ◽  
The Metabolic Syndrome ◽  
Low Carbohydrate ◽  
Fat Diets

Abstract The metabolic syndrome (MetS) comprises cardiometabolic risk factors frequently found in individuals with obesity. Guidelines to prevent or reverse MetS suggest limiting fat intake, however, lowering carbohydrate intake has gained attention too. The aim for this review was to determine to what extent either weight loss, reduction in caloric intake, or changes in macronutrient intake contribute to improvement in markers of MetS in persons with obesity without cardiometabolic disease. A meta-analysis was performed across a spectrum of studies applying low-carbohydrate (LC) and low-fat (LF) diets. PubMed searches yielded 17 articles describing 12 separate intervention studies assessing changes in MetS markers of persons with obesity assigned to LC (&lt;40% energy from carbohydrates) or LF (&lt;30% energy from fat) diets. Both diets could lead to weight loss and improve markers of MetS. Meta-regression revealed that weight loss most efficaciously reduced fasting glucose levels independent of macronutrient intake at the end of the study. Actual carbohydrate intake and actual fat intake at the end of the study, but not the percent changes in intake of these macronutrients, improved diastolic blood pressure and circulating triglyceride levels, without an effect of weight loss. The homeostatic model assessment of insulin resistance improved with both diets, whereas high-density lipoprotein cholesterol only improved in the LC diet, both irrespective of aforementioned factors. Remarkably, changes in caloric intake did not play a primary role in altering MetS markers. Taken together, these data suggest that, beyond the general effects of the LC and LF diet categories to improve MetS markers, there are also specific roles for weight loss, LC and HF intake, but not reduced caloric intake, that improve markers of MetS irrespective of diet categorization. On the basis of the results from this meta-analysis, guidelines to prevent MetS may need to be re-evaluated.

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.

scholarly journals Very low-carbohydrate high-fat diets are superior to low-fat diets in improving cardiovascular markers: meta-analysis of large, long-term randomised controlled trials

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Teuta Gjuladin-Hellon ◽  
Ian Davies ◽  
Jackie Fealey ◽  
Alexander Montasem ◽  
Katie Lane
Keyword(s):  
Total Cholesterol ◽  
Randomised Controlled Trials ◽  
Fasting Glucose ◽  
Meta Analysis ◽  
High Fat ◽  
Low Carbohydrate ◽  
High Fat Diets ◽  
Randomised Controlled ◽  
Fat Diets

AbstractOur recent study (1) showed that the amount of dietary carbohydrates in obesity interventions has differential effects on cardiovascular risk markers (CVM) and effects magnitude depends on intervention duration. Very-low carbohydrate high-fat diets (VLCD) were superior in ameliorating lipid markers compared to high-carbohydrate low-fat diets (LFD).We updated our systematic review and meta-analysis to include long-term effects of VLCD (< 50 g /day) on weight, glucose, total cholesterol, insulin and blood pressure (BP) among overweight/obese adults in comparison to LFD.Medline, PubMed, Cochrane Central, and CINAHLPlus were searched to identify large (n > 100) randomised controlled trials (RCT) with duration ≥ 6 months. Risk of bias, a random effects model and subgroup analyses based on duration of follow-up were performed using Review Manager. Results were reported according to PRISMA.Four open label RCT (n = 723; 362 VLCD; 361 LFD) with some form of behavioral intervention and duration 6–24 months were identified. VLCD showed more favorable effects on diastolic BP at 6 months (-1.96; 95%CI, -2.99 to 00.93; P = 0.0002) and 24 months (-2.69; 95%CI, -4.87 to -0.51; P = 0.001), near significant level at 12 months (-1.79; 95%CI, -3.56 to 0.04; P = 0.05) and an overall total favourable effect (-1.98; 95%CI, -2.73 to -1.22). The decrease in systolic BP was greater among VLCD for the whole period and the overall total effect reached the level of significance (-1.76; 95%CI, -3.56 to 0.04; P = 0.05). VLCD showed beneficial effect on total cholesterol level at 6 and 12 months (-0.01 mmol/L; 95%CI, -0.01 to –0.00; P = 0.002 and -0.01 mmol/L; 95%CI, -0.01 to –0.00; P = 0.005, respectively). The mean changes in weight, and fasting glucose and insulin levels revealed non-significant differences between both diets at any measured time, although these parameters decreased within both groups compared to baseline.VLCD led to significant total weighted mean decrease of diastolic BP and near significant decrease of systolic BP independent of changes in body weight, fasting glucose or insulin levels. The present data on decreased levels of diastolic BP and total cholesterol, combined with our recently published results on increased HDL-cholesterol, decreased triglycerides and no significant effect on LDL-cholesterol (1) provide evidence that VLCD are superior to LFD in improving traditional CVM in longer term.

Weight loss leads to reductions in inflammatory biomarkers after a very-low-carbohydrate diet and a low-fat diet in overweight men

2004 ◽  
Vol 107 (4) ◽  
pp. 365-369 ◽  
Author(s):  
Matthew J. SHARMAN ◽  
Jeff S. VOLEK
Keyword(s):  
Weight Loss ◽  
Body Mass ◽  
High Sensitivity ◽  
Inflammatory Biomarkers ◽  
Low Grade ◽  
Low Fat ◽  
Carbohydrate Diet ◽  
Low Carbohydrate Diet ◽  
Low Fat Diet ◽  
Low Carbohydrate

In recent years, it has become apparent that low-grade vascular inflammation plays a key role in all stages of the pathogenesis of atherosclerosis. Weight loss has been shown to improve blood inflammatory markers; however, it is unknown if weight-loss diets varying in macronutrient composition differentially affect inflammatory responses. The primary purpose of the present study was to compare a very-low-carbohydrate diet and a low-fat weight-loss diet on inflammatory biomarkers in overweight men. In a randomized cross-over design, 15 overweight men (body fat, >25%; body mass index, 34 kg/m2) consumed two experimental weight-loss diets for two consecutive 6-week periods: a very-low-carbohydrate diet (<10% energy via carbohydrate) and a low-fat diet (<30% energy via fat). Both the low-fat and the very-low-carbohydrate diets resulted in significant decreases in absolute concentrations of hsTNF-α (high-sensitivity tumour necrosis factor-α), hsIL-6 (high-sensitivity interleukin-6), hsCRP (high-sensitivity C-reactive protein) and sICAM-1 (soluble intercellular cell-adhesion molecule-1). There was no significant change in absolute sP-selectin (soluble P-selectin) concentrations after either diet. Normalized inflammatory values represented as the delta change per 1 kg reduction in body mass showed a significant difference between the two diets only for sP-selectin (P<0.05). In summary, energy-restricted low-fat and very-low-carbohydrate diets both significantly decreased several biomarkers of inflammation. These data suggest that, in the short-term, weight loss is primarily the driving force underlying the reductions in most of the inflammatory biomarkers.

scholarly journals Halo effect of a weight-loss trial on spouses: the DIRECT-Spouse study

2009 ◽  
Vol 13 (4) ◽  
pp. 544-549 ◽  
Author(s):  
Rachel Golan ◽  
Dan Schwarzfuchs ◽  
Meir J Stampfer ◽  
Iris Shai
Keyword(s):  
Weight Loss ◽  
Weight Change ◽  
Dietary Intervention ◽  
Controlled Trial ◽  
Halo Effect ◽  
Research Centre ◽  
Food Groups ◽  
Low Fat ◽  
Low Carbohydrate Diet ◽  
Low Carbohydrate

AbstractObjectiveWe examined the halo effect of a 2-year weight-loss diet trial, the Dietary Intervention Randomized Controlled Trial (DIRECT), on the weight and nutritional patterns of participants' spouses.DesignDIRECT participants in a research centre workplace were randomly assigned to one of three diets: Low-fat, Mediterranean or Low-carbohydrate. A sample of wives of the DIRECT participants, who attended support update meetings specific to their husband's diet during the first 6 months, were followed for 2 years.SettingSouth Israel.SubjectsSeventy-four women (mean age = 51 years, mean BMI =26·6 kg/m2).ResultsAmong the wives of husbands randomised to the Low-fat, Mediterranean and Low-carbohydrate diet, self-reported weight change was respectively −1·48 kg, −2·30 kg and −4·62 kg after 6 months, and +0·39 kg, −3·00 kg and −2·30 kg after 2 years. Weight loss among wives whose husbands were in the alternative diet groups combined (Mediterranean+Low-carbohydrate) was significantly greater than among wives whose husbands were in the Low-fat group after 6 months (P = 0·031) and 2 years (P = 0·034). Overweight wives experienced more weight loss. The weight change of couples was significantly correlated (r = 0·42, P < 0·001). Across all dietary groups, wives had significant improvement in their dietary patterns in all food groups according to their husbands' diets, mainly by a larger significant decrease in carbohydrate consumption in the Low-carbohydrate group (P = 0·013 compared to Low-fat). Six-month weight change among the seventy-four DIRECT participants whose wives took part in the group support sessions was −5·2 kg, compared to −3·5 kg among the 248 DIRECT participants whose wives did not take part in these sessions (P = 0·020).ConclusionsFocusing on the couple as a unit could provide a cost-effective approach to weight-loss programmes.

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