Hume Catherine, Jachs Barbara, Menzies John
Centre for Integrative Physiology, School of Biomedical Sciences, University of Edinburgh, Edinburgh, UK.
Obesity (Silver Spring). 2016 Oct;24(10):2126-32. doi: 10.1002/oby.21606. Epub 2016 Aug 20.
Energy intake is regulated by overlapping homeostatic and hedonic systems. Consumption of palatable foods has been implicated in weight gain, but this assumes that homeostatic control systems do not accurately detect this hedonically driven energy intake. This study tested this assumption, hypothesizing that satiated rats would reduce their voluntary food intake and maintain a stable body weight after consuming a palatable food.
Lean rats or rats previously exposed to an obesogenic diet were schedule-fed with fixed or varying amounts of palatable sweetened condensed milk (SCM) daily, and their voluntary energy intake and body weight were monitored.
During scheduled feeding of SCM, rats voluntarily reduced bland food consumption and maintained a stable body weight. This behavior was also seen in rats with access to an obesogenic diet and was independent of the predictability of SCM access. However, lean rats offered large amounts of SCM showed an increase in total energy intake. To test whether a nutrient deficiency drove this under-compensatory behavior, SCM was enriched with protein. However, no effect was seen on voluntary energy intake.
In schedule-fed rats, compensatory reductions in voluntary energy intake were seen, but under-compensation was observed if large amounts of SCM were consumed.
能量摄入由相互重叠的稳态和享乐系统调节。美味食物的摄入与体重增加有关，但这假定稳态控制系统无法准确检测这种由享乐驱动的能量摄入。本研究对这一假设进行了检验，假设饱足的大鼠在食用美味食物后会减少自愿食物摄入量并维持稳定体重。
对瘦鼠或先前接触过致肥胖饮食的大鼠每天定时喂食固定量或不同量的美味甜炼乳（SCM），并监测它们的自愿能量摄入量和体重。
在定时喂食SCM期间，大鼠会自愿减少清淡食物的摄入量并维持稳定体重。在接触过致肥胖饮食的大鼠中也观察到了这种行为，且与获取SCM的可预测性无关。然而，给瘦鼠提供大量SCM时，其总能量摄入量增加。为了测试是否是营养缺乏导致了这种补偿不足的行为，在SCM中添加了蛋白质。然而，对自愿能量摄入没有影响。
在定时喂食的大鼠中，观察到了自愿能量摄入的补偿性减少，但如果食用大量SCM，则会出现补偿不足的情况。
