Calorie restriction (CR) and alternate-day fasting (ADF) beneficially affect several aspects of adipose tissue physiology, but direct comparisons between regimens have yet to be performed. The present study evaluated the effects of ADF versus CR on body fat distribution and circulating adiponectin levels and examined the kinetic mechanisms that underlie changes in fat distribution. Thirty female C57BL/6J mice were randomized to one of five groups for 4 weeks: (a) CR-25% (25% energy restriction daily), (b) ADF-75% (75% restriction on fast day), (c) ADF-85% (85% restriction on fast day), (d) ADF-100% (100% restriction on fast day) and (e) control (ad libitum fed). Body weights of the CR mice were lower than that of the ADF and control groups posttreatment. After 4 weeks of diet, the proportion of visceral fat decreased (P<.001) and the proportion of subcutaneous fat increased (P<.001) similarly in ADF and CR animals. Adiponectin increased (P<.05) by 62-86% in the ADF groups and by 69% in the CR group. Triglyceride (TG) synthesis and de novo lipogenesis were augmented (P<.05) in the subcutaneous fat pad of ADF and CR animals, relative to control. No differences in net lipolysis were observed, resulting in greater TG accumulation in the subcutaneous fat pad, with a shift in the ratio of TG between depots. These findings indicate that ADF (both modified and true) produces similar beneficial modulations in body fat distribution and adiponectin levels as daily CR.
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