Alternate Day Fasting Versus Calorie Restriction for Weight Maintenance

A study that investigated whether alternate day modified fasting (ADF) produces superior changes in body weight, coronary heart disease (CHD) risk, and eating behaviors during weight loss maintenance when compared to traditional daily calorie restriction (CR) regimens was conducted in overweight and obese adults. Sedentary subjects were randomized to 1 of 3 groups (1) ADF, 2) CR, or 3) control) for a 24-week weight loss phase followed by a 24-week weight loss maintenance phase. The ADF diet implemented a 75% energy restriction “fast day” with a 125% intake “feed day” for weight loss and a 50% energy restriction “fast day” with a 150% intake “feed day” for weight loss maintenance. The CR diet consisted of a daily 25% restriction during the weight loss phase and a 100% daily intake regimen for weight loss maintenance. The control diet ate their usual diet for the duration of the study. Body weight, CHD risk indicators, and eating behaviors were measured at baseline, week 24, and week 48 for each group. Body weight decreased in both intervention groups during the weight loss phase and remained decreased by the end of the weight maintenance phase when compared to controls. Fat mass, insulin, HOMA-IR, and leptin decreased in both groups during the weight loss phase compared to controls, but these changes were no longer significant compared to baseline by the end of the maintenance phase. There were no between group changes in fat free mass, visceral fat, blood pressure, heart rate, lipids, adiponectin, resistin, IL-6, CRP, appetite, dietary restraint, or self-efficacy at any time point. These findings suggest that the ADF diet may be effective for weight loss maintenance but may not be superior to traditional methods used for weight loss and weight maintenance. Neither intervention lead to sustained improvements in CHD risk indicators during the weight maintenance phase. Additionally, the role of eating behavior change in modulating these effects remains unclear.