Mohammad Hasan Entezari
1, Mohammad Salehi
2, Mahmoud Rafieian-Kopaei
3, Marzieh Kafeshani
1*1 Food Security Research Center and Department of Clinical Nutrition /Community Nutrition /Food Science& Technology, School of Nutrition & Food Science, Isfahan University of Medical Sciences, Isfahan, Iran
2 Department of Epidemiology and Biostatistics, School of Public Health, Isfahan University of Medical Sciences, Isfahan, Iran
3 Medical Plants Research Center, Shahrekord University of Medical Sciences, Shahrekord, Iran
Abstract
The effect of dietary macronutrient proportion on insulin resistance is controversial. The objective of this study was to conduct a systematic review and meta-analysis on randomized controlled trials (RCTs) that examine the effects of replacing dietary fat with carbohydrate on insulin resistance. We searched PubMed, Google Scholar, Science Direct, and ISI Web of Science for RCTs until 2011. In total we found 15 articles that examine the effects of two kinds of prescribed diets low-fat, high-carbohydrate (LFHC) diet and high-fat low-carbohydrate (HFLC) diet on insulin resistance as regard the inclusion criteria. Meta-analysis of data from all 15 selected studies found that there is not significant difference between HFLC diet and LFLC diet (mean difference 0.01; 95% confidence interval [CI], -0.18 to 0.2; P > 0.05), but when two studies were excluded from the meta-analysis a significant difference was seen between HFLC diet and LFLC diet (mean difference 0.01; 95% CI, -0.17 to -0.02; P =0.009). Our findings suggested that HFLC diet significantly decreases insulin resistance compared with the LFLC diet. But we cannot conclude a LFHC diet is unfavorable compared with an HFLC diet for insulin resistant patients because in this study we have not determined the type of carbohydrate and fat intake, while dietary fat and carbohydrate composition may be a particularly important means of improving insulin sensitivity.