Meal timing during alternate day fasting: effects on body weight and coronary heart disease risk in obese adults (47.5)

Abstract

Alternate day fasting (ADF), consisting of a feed day (24‐h ad libitum food intake) alternated with a fast day (25% energy intake at lunchtime), results in moderate weight loss (3‐4 kg) in 8 weeks. It has been speculated that moving the fast day meal to dinnertime, or dividing the meal into smaller meals, may improve adherence and weight loss. Accordingly, this study compared the effects of three ADF protocols with different fast day meal times on body weight and coronary heart disease (CHD) risk. Obese subjects (n = 45) were randomized to 1 of 3 groups for 8 weeks: 1) ADF‐L: fast day meal as lunch, 2) ADF‐D: fast day meal as dinner, or 3) ADF‐SM: fast day meal as small meals throughout the day. Body weight decreased (P < 0.05) to a greater extent in the ADF‐D (4.6 ± 0.6 kg) and ADF‐SM (4.9 ± 0.6 kg) groups, compared to the ADF‐L (3.3 ± 0.6 kg) group. Fat mass and visceral fat mass also decreased (P < 0.05) to a greater extent by ADF‐D (3.1 ± 0.3 kg; 0.2 ± 0 kg) and ADF‐SM (3.3 ± 0.4 kg; 0.2 ± 0 kg), versus ADF‐L (1.8 ± 0.4 kg; 0.1 ± 0 kg). Systolic blood pressure decreased (P < 0.05) only in the ADF‐SM group (19 ± 10 mm Hg), while diastolic blood pressure and heart rate remained unchanged. These findings suggest that allowing individuals to consume the fast day meal at dinner or as small meals throughout the day may increase weight loss with ADF. The effect of these regimens on CHD risk warrants further investigation.