Department of Psychology, University of Illinois at Urbana-Champaign , Champaign, Illinois.
Research Diets Inc , New Brunswick, New Jersey.
Am J Physiol Regul Integr Comp Physiol. 2019 Feb 1;316(2):R130-R143. doi: 10.1152/ajpregu.00231.2018. Epub 2018 Nov 7.
The modern environment is characterized by convenient access to a variety of high-fat (HF) foods and encourages excess energy intake, which leads to weight gain. While healthier diets and exercise are common interventions that facilitate energy balance, meal patterns also influence body weight and energy metabolism. The current study characterized the association among exercise, diet choice, and meal patterns in rats. Unlike sedentary rats, which prefer a HF to a chow diet, wheel-running rats initially avoid the HF diet. Subsequently, the running-induced HF diet avoidance persists longer in males than in females. We hypothesized that differences in meal patterns contribute to sex differences in the prevalence and persistency of HF diet avoidance. During two-diet choice, rats did not mix chow and HF diet within a meal and consumed discrete meals of each diet. Exercise decreased chow meal size in both sexes (4.5 vs. 5.7 kcal) but decreased total meal frequency only in male rats. Analyses of individual differences revealed WR rats that maintained HF diet avoidance (HF avoiders) had larger chow than HF meals (5.2 vs. 1.3 kcal) upon initial 3 days of diet choice. When compared with rats that reversed HF avoidance (HF eaters), HF avoiders had shorter latency to consume their first meal of HF diet (2.6 vs. 98.9 min) upon initial running and diet choice. Taken together, these results suggest that both sex and individual differences in meal patterns contribute to differences in the persistency of exercise-associated HF diet avoidance.
现代环境的特点是可以方便地获得各种高脂肪（HF）食物，并鼓励摄入过多的能量，从而导致体重增加。虽然更健康的饮食和运动是促进能量平衡的常见干预措施，但进餐模式也会影响体重和能量代谢。本研究描述了运动、饮食选择和进餐模式之间在大鼠中的关联。与久坐不动的大鼠不同，它们更喜欢高脂肪饮食而不是标准饮食，而轮跑大鼠最初会避免高脂肪饮食。随后，雄性大鼠比雌性大鼠更能持续更长时间地避免高脂肪饮食。我们假设，进餐模式的差异导致了大鼠对高脂肪饮食回避的普遍性和持续性的性别差异。在两种饮食选择中，大鼠不会在一餐中混合标准饮食和高脂肪饮食，而是会分别进食每一种饮食。运动使两性的标准饮食餐量减少（4.5 与 5.7 千卡），但仅使雄性大鼠的总餐频率减少。对个体差异的分析表明，在最初的 3 天饮食选择中，保持高脂肪饮食回避的轮跑大鼠（高脂肪回避者）的标准饮食餐量大于高脂肪饮食餐量（5.2 与 1.3 千卡）。与逆转高脂肪回避的大鼠（高脂肪进食者）相比，高脂肪回避者在初始跑步和饮食选择时，首次进食高脂肪饮食的潜伏期更短（2.6 与 98.9 分钟）。综合这些结果表明，性别和进餐模式的个体差异都导致了运动相关的高脂肪饮食回避的持续性差异。
