Bake T, Murphy M, Morgan D G A, Mercer J G
University of Aberdeen, Rowett Institute of Nutrition and Health, Ingestive Behaviour Group, Bucksburn, Aberdeen, UK.
AstraZeneca, Mereside, Alderley Park, Macclesfield, UK.
Appetite. 2014 Jun;77(100):60-71. doi: 10.1016/j.appet.2014.02.020. Epub 2014 Mar 12.
Male C57BL/6 mice fed ad libitum on control diet but allowed access to a palatable high fat diet (HFD) for 2 h a day during the mid-dark phase rapidly adapt their feeding behaviour and can consume nearly 80% of their daily caloric intake during this 2 h-scheduled feed. We assessed food intake microstructure and meal pattern, and locomotor activity and rearing as markers of food anticipatory activity (FAA). Schedule fed mice reduced their caloric intake from control diet during the first hours of the dark phase but not during the 3-h period immediately preceding the scheduled feed. Large meal/binge-like eating behaviour during the 2-h scheduled feed was characterised by increases in both meal number and meal size. Rearing was increased during the 2-h period running up to scheduled feeding while locomotor activity started to increase 1 h before, indicating that schedule-fed mice display FAA. Meal number and physical activity changes were sustained when HFD was withheld during the anticipated scheduled feeding period, and mice immediately binged when HFD was represented after a week of this "withdrawal" period. These findings provide important context to our previous studies suggesting that energy balance systems in the hypothalamus are not responsible for driving these large, binge-type meals. Evidence of FAA in HFD dark phase schedule-fed mice implicates anticipatory processes in binge eating that do not involve immediately preceding hypophagia or regulatory homeostatic signalling.
雄性C57BL/6小鼠随意进食对照饮食,但在黑暗期中期每天有2小时可进食美味的高脂饮食(HFD),它们会迅速调整进食行为,在这2小时的定时进食期间可摄入近80%的每日热量。我们评估了食物摄入微观结构和进食模式,以及运动活动和竖毛行为作为食物预期活动(FAA)的指标。定时喂食的小鼠在黑暗期的最初几个小时减少了对照饮食的热量摄入,但在预定喂食前的3小时内没有减少。在2小时的预定喂食期间,大量进食/暴饮暴食行为的特点是进食次数和进食量均增加。在预定喂食前的2小时内竖毛行为增加,而运动活动在提前1小时开始增加,这表明定时喂食的小鼠表现出FAA。当在预期的预定喂食期不提供HFD时,进食次数和身体活动的变化持续存在,并且在一周的“禁食”期后重新提供HFD时,小鼠会立即暴饮暴食。这些发现为我们之前的研究提供了重要背景,表明下丘脑的能量平衡系统并不负责驱动这些大量的、暴饮暴食型进食。在黑暗期定时喂食HFD的小鼠中存在FAA的证据表明,暴饮暴食中存在预期过程,这并不涉及紧接在前的摄食减少或调节性稳态信号。