ABSTRACT
Abnormal meal timing, like skipping breakfast and late-night snacking, is associated with obesity in humans. Disruption of daily eating rhythms also contributes to obesity in mice. When fed a high-fat diet, male C57BL/6J mice have disrupted eating behavior rhythms and they become obese. In contrast to obesity-prone C57BL/6J mice, some inbred strains of mice are resistant to high-fat diet-induced obesity. In this study, we sought to determine whether there are distinct effects of high-fat feeding on daily eating behavior rhythms in obesity-prone and obesity-resistant male mice. Male obesity-prone (C57BL/6J and 129X1/SvJ) and obesity-resistant (SWR/J and BALB/cJ) mice were fed low-fat diet or high-fat diet for 6 wk. Consistent with previous studies, obesity-prone male mice gained more weight and adiposity during high-fat diet feeding than obesity-resistant male mice. The amplitude of the daily rhythm of eating behavior was markedly attenuated in male obesity-prone mice fed high-fat diet, but not in obesity-resistant males. In contrast, high-fat feeding did not differentially affect locomotor activity rhythms in obesity-prone and obesity-resistant male mice. Together, these data suggest that regulation of the daily rhythm of eating may underlie the propensity to develop diet-induced obesity in male mice.