Effects of Low-Carbohydrate Diets Versus Low-Fat Diets on Metabolic Risk Factors: A Meta-Analysis of Randomized Controlled Clinical Trials

Abstract

The effects of low-carbohydrate diets (≤45% of energy from carbohydrates) versus low-fat diets (≤30% of energy from fat) on metabolic risk factors were compared in a meta-analysis of randomized controlled trials. Twenty-three trials from multiple countries with a total of 2,788 participants met the predetermined eligibility criteria (from January 1, 1966 to June 20, 2011) and were included in the analyses. Data abstraction was conducted in duplicate by independent investigators. Both low-carbohydrate and low-fat diets lowered weight and improved metabolic risk factors. Compared with participants on low-fat diets, persons on low-carbohydrate diets experienced a slightly but statistically significantly lower reduction in total cholesterol (2.7 mg/dL; 95% confidence interval: 0.8, 4.6), and low density lipoprotein cholesterol (3.7 mg/dL; 95% confidence interval: 1.0, 6.4), but a greater increase in high density lipoprotein cholesterol (3.3 mg/dL; 95% confidence interval: 1.9, 4.7) and a greater decrease in triglycerides (-14.0 mg/dL; 95% confidence interval: -19.4, -8.7). Reductions in body weight, waist circumference and other metabolic risk factors were not significantly different between the 2 diets. These findings suggest that low-carbohydrate diets are at least as effective as low-fat diets at reducing weight and improving metabolic risk factors. Low-carbohydrate diets could be recommended to obese persons with abnormal metabolic risk factors for the purpose of weight loss. Studies demonstrating long-term effects of low-carbohydrate diets on cardiovascular events were warranted.

Personalized weight loss strategies—the role of macronutrient distribution

“…However, following a low-carbohydrate diet is also associated with increased all-cause mortality, 58 impaired flow-mediated dilatation, 59 and increased LDL-cholesterol levels, 50 although contradictory evidence exists on the latter point. 41 Some researchers have suggest that stressing the modest benefits observed for particular types of diet or macronutrient contents should be discouraged, given the lack of long-term evidence.…”

“…No adverse effects were observed after 12 months in patients following the Atkins diet, 40 which was in accordance with the results of previous short-term studies and critical reviews. 22,41,42 However, the authors could not establish whether the increased weight loss was due to the reduced carbohydrate content or the increased amount of protein in the Atkins diet.…”

Asociación del polimorfi smo TNF-alpha -308 G/A con los cambios metabólicos secundarios a una dieta hipocalórica rica en proteínas/baja en hidratos de carbono versus una dieta hipocalórica estándar

“…Finally, carriers of the -308 GG promoter variant of TNF-alpha gene have a better metabolic response than A allele carriers with a high polyunsaturated fat hypocaloric diet (10). On the other hand, recent studies have suggested no major differences between the effects of various dietary approaches, including low-carbohydrate and low-fat diets, on body weight outcomes (11,12). However, other studies have reported that very low-carbohydrate ketogenic diets and the Mediterranean diet are superior to low-fat diets in reducing body weight (13,14).…”

Obesity Etiology: Examination of Fast-Food Eating among College Students

“…Other literature examining the proportion of fat, carbohydrate, and protein in the diet has found that low carbohydrate was more beneficial for weight loss and did not adversely affect the lipid fractions on a standard metabolic blood profile [16, [25][26][27][28][29][30][31]. While recent studies are examining the role of a high fat diet as a contributing factor for bacterial endotoxins (lipopolysaccharides) which trigger toll-like receptors preparatory to inflammation and inflammation is the key driver for chronic disease of which Type 2 Diabetes Mellitus (T2DM) and obesity are foremost [28][29][30][31].…”

“…While recent studies are examining the role of a high fat diet as a contributing factor for bacterial endotoxins (lipopolysaccharides) which trigger toll-like receptors preparatory to inflammation and inflammation is the key driver for chronic disease of which Type 2 Diabetes Mellitus (T2DM) and obesity are foremost [28][29][30][31]. Marcos et al state that there are numerous pathological situations where nutrients (fat, carbohydrate, protein, vitamins, minerals) play a primary or secondary determinant role for some underlying immunological impairment of which obesity is now subsumed [32].…”