Smith S R, de Jonge L, Zachwieja J J, Roy H, Nguyen T, Rood J, Windhauser M, Volaufova J, Bray G A
Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
Am J Clin Nutr. 2000 Jul;72(1):131-8. doi: 10.1093/ajcn/72.1.131.
It takes several days to adapt to a high-fat diet. In an earlier study, we observed a large degree of interindividual variation in the capacity to adapt to a high-fat diet. We hypothesized that concurrent physical activity would accelerate fat oxidation during an isoenergetic high-fat diet.
The objective of this study was to determine the effect of increased physical activity on the ability of young healthy men to increase fat oxidation during the shift to a high-fat diet.
Six young healthy men participated in a randomized, single-blind crossover study. The volunteers consumed a diet contributing 37% of energy as fat, 14% as protein, and 49% as carbohydrate for 4 d. Energy expenditure and macronutrient balance were then measured in a respiration chamber as the energy content of the isoenergetic diet was changed to 50% fat, 14% protein, and 36% carbohydrate. Treadmill walking, as the physical activity, was used to increase total daily energy expenditure to 1.8 times the resting metabolic rate during 1 of 2 stays in the metabolic chamber. Total daily energy expenditure was maintained at 1.4 times the resting metabolic rate for the other stay.
Energy balance was not significantly different between the 2 conditions. The 24-h respiratory quotient decreased more rapidly and to a greater extent under conditions of increased energy expenditure. Further, there was a decrease in the interindividual variability in the response of the respiratory quotient to a high-fat diet with increased energy expenditure (physical activity). Cumulative carbohydrate and protein balances were greater under conditions of increased physical activity. Conversely, cumulative fat balance was greater under sedentary conditions.
Concurrent physical activity increases fat oxidation during the shift to a high-fat diet.
适应高脂饮食需要数天时间。在早期的一项研究中，我们观察到个体在适应高脂饮食的能力上存在很大差异。我们假设，在等能量高脂饮食期间，同时进行体育活动会加速脂肪氧化。
本研究的目的是确定增加体育活动对年轻健康男性在转向高脂饮食过程中增加脂肪氧化能力的影响。
六名年轻健康男性参与了一项随机、单盲交叉研究。志愿者连续4天摄入一种饮食，其中脂肪提供37%的能量，蛋白质提供14%的能量，碳水化合物提供49%的能量。然后，在呼吸室内测量能量消耗和常量营养素平衡，此时等能量饮食的能量组成变为50%脂肪、14%蛋白质和36%碳水化合物。在代谢室停留的两个阶段中的一个阶段，通过跑步机行走作为体育活动，使每日总能量消耗增加至静息代谢率的1.8倍。在另一个阶段，每日总能量消耗维持在静息代谢率的1.4倍。
两种情况下的能量平衡无显著差异。在能量消耗增加的情况下，24小时呼吸商下降得更快且幅度更大。此外，随着能量消耗（体育活动）增加，呼吸商对高脂饮食反应的个体间变异性降低。在体育活动增加的情况下，碳水化合物和蛋白质的累积平衡更大。相反，在久坐不动的情况下，脂肪累积平衡更大。
在转向高脂饮食期间，同时进行体育活动可增加脂肪氧化。
