Hambly Catherine, Adams Andrew, Fustin Jean-Michel, Rance Kellie A, Bünger Lutz, Speakman John R
School of Biological Sciences, Aberdeen Center for Energy Regulation and Obesity, University of Aberdeen, Aberdeen, UK.
Obes Res. 2005 Mar;13(3):556-66. doi: 10.1038/oby.2005.59.
Mice divergently selected for high or low food intake (FI) at constant body mass differ in their resting metabolic rates (RMRs). Low-intake individuals (ML) have significantly lower RMR (by 30%) compared with those from the high-intake line (MH). We hypothesized that MLs might, therefore, be more likely to increase their body and fat mass when exposed to a high-fat diet (HFD).
We exposed both lines to a diet with 44.9% calories from fat for 3 weeks while measuring FI, fecal production, and body mass and then returned the mice to standard chow.
When exposed to the HFD, both lines significantly decreased their FI (MH, 40% to 45%; ML, 31% to 35%). This decrease occurred simultaneously with a significant increase in apparent energy absorption efficiency (AEAE). When returned to chow, FI and AEAE returned to the levels observed prior to HFD exposure. Because of the adjustments in FI, the absorbed energy was maintained in the MLs and, thus, body mass remained constant. The MH individuals overcompensated for the elevated energy content and AEAE on the HFD and, therefore, absorbed lower energy than when feeding on chow. These mice also did not significantly change their body mass when on the HFD and must have made adjustments in their energy expenditures. Both lines and both sexes increased in fat content on the HFD, but these effects were not different between lines or sexes.
We found no support for the hypothesis that mice with low RMRs were more susceptible to weight gain when fed the HFD.
在恒定体重下针对高或低食物摄入量（FI）进行趋异选择的小鼠，其静息代谢率（RMR）存在差异。与来自高摄入量品系（MH）的小鼠相比，低摄入量个体（ML）的RMR显著更低（低30%）。因此，我们推测，当暴露于高脂饮食（HFD）时，ML个体可能更有可能增加体重和脂肪量。
我们让两个品系的小鼠都摄入脂肪热量占44.9%的饮食，持续3周，同时测量FI、粪便产生量和体重，然后将小鼠换回标准食物。
当暴露于HFD时，两个品系的小鼠FI均显著下降（MH，从40%降至45%；ML，从31%降至35%）。这种下降与表观能量吸收效率（AEAE）的显著增加同时发生。当换回标准食物时，FI和AEAE恢复到HFD暴露前观察到的水平。由于FI的调整，ML个体吸收的能量得以维持，因此体重保持不变。MH个体对HFD上能量含量和AEAE的升高进行了过度补偿，因此吸收的能量比喂食标准食物时更低。这些小鼠在HFD喂养期间体重也没有显著变化，它们一定在能量消耗方面进行了调整。两个品系以及雌雄两性在HFD喂养下脂肪含量均增加，但品系或性别之间的这些影响并无差异。
我们没有找到证据支持以下假设，即RMR低的小鼠在喂食HFD时更容易体重增加。
