Alternate‐day fasting reduces the ratio of visceral to subcutaneous fat by modulating adipose tissue triglyceride metabolism in mice

BACKGROUND: Calorie restriction (CR) regimens reduce visceral adiposity in non‐obese animals. The effects of alternate‐day fasting (ADF) regimens on fat distribution are not known. OBJECTIVE: To investigate the effects of ADF on body fat distribution in mice, and to determine the lipid dynamics underlying redistribution of fat among depots. METHODS: In a 2‐week study, 24 male C57BL/6J mice were randomized to 1 of 2 groups: ADF‐100% (24 h of 100% CR, alternating with 24 h ad libitum feeding) or control (ad libitum fed everyday). RESULTS: Body weight did not differ between groups. The epidydimal (visceral) fat depot of the ADF‐100% group was 31% smaller (P < 0.01), while the inguinal (subcutaneous) fat depot was 45% larger (P < 0.01), compared to controls. Absolute TG synthesis in the ADF‐100% group was higher (P < 0.05) in inguinal fat and lower (P < 0.05) in epidydimal fat than in controls. No differences in net lipolysis were observed between groups in either fat pad. Net TG accumulation in ADF‐100% mice was higher (P < 0.05) in inguinal fat and lower (P < 0.05) in epidydimal fat, relative to controls. Epidydimal fat cells were 56% smaller (P < 0.05) in the ADF‐100% group, post‐treatment, relative to controls. CONCLUSION: These findings suggest that short‐term ADF redistributes adipose TG from visceral to subcutaneous depots by augmenting TG synthesis in inguinal fat, while lowering it in epidydimal fat.