Short-term modified alternate-day fasting: a novel dietary strategy for weight loss and cardioprotection in obese adults

Background: The ability of modified alternate-day fasting (ADF; ie, consuming 25% of energy needs on the fast day and ad libitum food intake on the following day) to facilitate weight loss and lower vascular disease risk in obese individuals remains unknown. Objective: This study examined the effects of ADF that is administered under controlled compared with self-implemented conditions on body weight and coronary artery disease (CAD) risk indicators in obese adults. Design: Sixteen obese subjects (12 women, 4 men) completed a 10-wk trial, which consisted of 3 phases: 1) a 2-wk control phase, 2) a 4-wk weight loss/ADF controlled food intake phase, and 3 )a 4-wk weight loss/ADF self-selected food intake phase. Results: Dietary adherence remained high throughout the controlled food intake phase (days adherent: 86%) and the self-selected food intake phase (days adherent: 89%). The rate of weight loss remained constant during controlled food intake (0.67 6 0.1 kg/wk) and selfselected food intake phases (0.68 6 0.1 kg/wk). Body weight decreased (P , 0.001) by 5.6 6 1.0 kg (5.8 6 1.1%) after 8 wk of diet. Percentage body fat decreased (P , 0.01) from 45 6 2% to 42 6 2%. Total cholesterol, LDL cholesterol, and triacylglycerol concentrations were lowered (P , 0.01) by 21 6 4%, 25 6 10%, and 32 6 6%, respectively, after 8 wk of ADF, whereas HDL cholesterol remained unchanged. Systolic blood pressure decreased (P , 0.05) from 124 6 5 to 116 6 3 mm Hg. Conclusion: These findings suggest that ADF is a viable diet option to help obese individuals lose weight and decrease CAD risk. This trial was registered at clinicaltrials.gov as UIC-004-2009. Am J Clin Nutr doi: 10.3945/ajcn.2009.28380.