Changes in Body Weight in Relation to Appetite During 6 Months of Alternate Day Fasting with a Low Carbohydrate Diet

Abstract

OBJECTIVES: Alternate day fasting (ADF) has been shown to lower body weight and improve subjective appetite by increasing fullness over time. What remains unknown, however, is whether carbohydrate restriction during ADF would provide additional weight loss benefits by helping to lower hunger as well. Accordingly, this study examined the effect of 6-months of ADF combined with a low carbohydrate diet on fasting and postprandial appetite ratings. The relationship between changes in appetite and body weight was also examined. METHODS: Adults with obesity (n = 31) participated in ADF (600 kcal “fast day” alternated with an ad libitum “feast day”) with a low‐carbohydrate background diet (30% carbohydrates, 35% protein, and 35% fat). The 6‐month trial consisted of a 3‐ month weight loss period followed by a 3‐month weight maintenance period. RESULTS: Body weight (P < 0.001) decreased by 5.5 ± 0.5% by month 3 (end of weight loss period) and by 6.3 ± 1.0% by month 6 (end of weight maintenance period). Subjective hunger and fullness did not change during the weight loss period, or the weight maintenance period. Hunger and fullness were not related to changes in body weight during the weight loss or weight maintenance periods. Fasting insulin decreased (P = 0.03) by − 24 ± 8% by month 6 relative to baseline. Fasting glucose and homeostatic model assessment of insulin resistance (HOMA‐IR), remained unchanged over the course of the study. CONCLUSIONS: These findings suggest that ADF combined with a low carbohydrate diet is an effective way of lowering body weight. However, these weight loss benefits are not related to improvements in hunger or fullness. FUNDING SOURCES: Nestle Health Sciences.