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 +/- 0.1 kg/wk) and self-selected food intake phases (0.68 +/- 0.1 kg/wk). Body weight decreased (P < 0.001) by 5.6 +/- 1.0 kg (5.8 +/- 1.1%) after 8 wk of diet. Percentage body fat decreased (P < 0.01) from 45 +/- 2% to 42 +/- 2%. Total cholesterol, LDL cholesterol, and triacylglycerol concentrations decreased (P < 0.01) by 21 +/- 4%, 25 +/- 10%, and 32 +/- 6%, respectively, after 8 wk of ADF, whereas HDL cholesterol remained unchanged. Systolic blood pressure decreased (P < 0.05) from 124 +/- 5 to 116 +/- 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.