Division of Developmental & Cognitive Neuroscience, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States.
Physiol Behav. 2013 Jul 2;119:190-4. doi: 10.1016/j.physbeh.2013.06.014. Epub 2013 Jun 28.
The complex, interacting influences on eating behavior and energy expenditure prevent elucidation of the causal role of any single factor in the current obesity epidemic. However, greater variety in the food supply, particularly in the form of highly palatable, energy-dense foods, has likely made a contribution. This study was undertaken to test the hypothesis that greater dietary variety is associated with greater caloric intake within individual meals consumed by free-feeding, socially-housed female rhesus monkeys. Meal patterns were assessed during two, two-week dietary phases. One phase consisted of a choice between a standard chow diet and a highly palatable diet (HPD). The other phase consisted of access to the chow only. Food intake for each subject was recorded continuously using previously validated, automated feeders, and a meal was defined based on a minimum kilocalorie requirement and a minimum inter-meal interval. During the choice condition, animals electively consumed mixed meals that incorporated both diets as well as other meals that consisted exclusively of a single diet - chow-only or HPD-only. Animals consumed the most calories per meal when the meal was comprised of both the chow and HPD, which differed in caloric density, flavor, and texture. Interestingly, however, there was no significant difference in the amount of calories consumed as HPD-only meals in the choice condition compared to meals in the chow-only, no choice condition, suggesting consumption of a single food during a meal, regardless of palatability, provides a constant sensory experience that may lead to more rapid habituation and subsequent meal cessation. Additionally, during the dietary choice condition, animals consumed fewer calories in the form of chow-only meals. Thus, the present results suggest that limiting dietary variety, regardless of palatability, may be a useful strategy for weight loss in overweight and obese individuals by reducing caloric intake within individual meals.
饮食行为和能量消耗受到多种因素的复杂相互影响，这使得任何单一因素在当前肥胖流行中的因果作用都难以确定。然而，食物供应的多样性增加，尤其是高美味、高能量食物的形式，可能起到了一定的作用。本研究旨在检验以下假设：在自由取食、群居的雌性恒河猴摄入的单次进食中，饮食多样性的增加与热量摄入的增加有关。在两个为期两周的饮食阶段中评估了进食模式。一个阶段是在标准食物和高美味食物（HPD）之间进行选择。另一个阶段只提供标准食物。使用先前验证的自动化喂食器连续记录每个动物的食物摄入量，定义一顿饭的依据是最低卡路里需求和最短进食间隔。在选择条件下，动物会选择性地摄入混合餐，这些混合餐包含两种饮食，还有其他只包含单一饮食的餐食，即只包含标准食物或 HPD。当餐食中同时包含标准食物和 HPD 时，动物每顿饭摄入的卡路里最多，因为这两种食物在热量密度、味道和质地上有所不同。然而，有趣的是，在选择条件下，与只摄入 HPD 的餐食相比，只摄入 HPD 的餐食所摄入的卡路里量没有显著差异，这表明在一顿饭中只摄入一种食物，无论其美味程度如何，都会提供一种恒定的感官体验，可能导致更快的习惯化和随后的进食停止。此外，在饮食选择条件下，动物摄入的标准食物（即只含标准食物的餐食）的卡路里量减少。因此，本研究结果表明，限制饮食多样性，无论其美味程度如何，可能是超重和肥胖人群减少单次进食热量摄入、从而达到减肥目的的一种有效策略。
