Alternate Day Fasting with a High Fat Versus Low Fat Diet for Weight Loss and Cardio-Protection

2013-10-24T00:00:00Z (GMT) by Monica C. Klempel
A randomized control trial examining the effects of alternate day fasting (ADF) with a high fat (HF) or low fat (LF) background diet on body weight and coronary heart disease (CHD) risk in obese humans was conducted over 10 weeks. Obese subjects were randomized to either an ADF-HF (45% fat) group or ADF-LF (25% fat) group. The 10-week study consisted of a 2-week baseline weight maintenance period, followed by an 8-week weight loss period. Food was provided to all subjects during the 10-week trial. During each study week, subjects came to the Human Nutrition Research Unit for body weight, body composition, waist circumference, and blood pressure measurements. At week 1, 3, and 10, vascular function, plasma lipids, and plasma adipokines were assessed. Results reveal that the ADF-HF diet is equally as effective as an ADF-LF diet in helping obese subjects lose weight and improve CHD risk factors. Body weight reductions were comparable between the ADF-HF diet and the ADF-LF diet, with no differences between groups. Similar decreases in fat mass were also observed for the ADF-HF and ADF-LF groups, with retention of lean mass. Reductions in several key biomarkers for CHD risk, such as total cholesterol, LDL cholesterol, and triacylglycerols, were also comparable between the HF and LF diet regimens. Moreover, the ADF-HF diet was as effective as the ADF-LF intervention at increasing LDL particle size, elevating the proportion of large LDL particles, and decreasing the proportion of small LDL particles. HDL particle size and distribution were not affected by either diet. As for endothelial function, ADF-LF diets increased brachial artery flow mediated dilation (FMD) while ADF-HF diets decreased FMD. Both intervention groups demonstrated increases in adiponectin and decreases in leptin and resistin. However, only adiponectin was positively correlated with FMD in the ADF-LF group. Taken together, these data suggest that individuals who typically consume HF foods do not need to lower the fat content of their diet to experience the benefits of ADF.