Larson D E, Rising R, Ferraro R T, Ravussin E
Clinical Disabetes and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona 85016, USA.
Int J Obes Relat Metab Disord. 1995 May;19(5):331-7.
To investigate the relationship between obesity and ad libitum food intake (quantity and composition) and to assess the impact of ad libitum food intake on energy expenditure and macronutrient oxidation.
Male volunteers were first fed a weight maintaining diet for at least 4 days before selecting their food for the next 5 days from two computerized vending machines offering a variety of familiar, palatable foods. 24-h energy expenditure (24EE) and substrate oxidation were measured in a respiratory chamber on the last day of each weight maintenance and ad libitum intake periods.
Ten day admission on a metabolic research ward.
Thirty-four non-diabetic Pima Indian males covering a wide range of body weight and body composition (30 +/- 8 y, 102.1 +/- 30.2 kg, 34 +/- 9% body fat, mean +/- s.d.).
Weight maintenance requirements averaged 2913 +/- 342 kcal/d. Energy intake during the ad libitum period increased to 4550 +/- 921 kcal/d (12 +/- 1% protein, 40 +/- 4% fat, 48 +/- 4% carbohydrate) i.e., a spontaneous overeating by 54 +/- 32% above weight maintenance requirement, resulting in a 0.9 +/- 1.0 kg body weight gain. Neither the composition of the selected diet nor the degree of overeating was associated with physical characteristics, such as body weight and body composition. When compared with baseline, spontaneous overeating on day 5 was associated with a 396 +/- 233 kcal/d increase in 24EE, a 607 +/- 503 kcal/d increase in carbohydrate oxidation, a 214 +/- 392 kcal/d decreased in lipid oxidation (P < 0.01), and no change in protein oxidation. Increased carbohydrate oxidation correlated with the excess carbohydrate intake (r = 0.69, P = 0.0001) accounting for 68 +/- 13% (mean +/- s.e.e.) of the excess, whereas excess fat intake was not oxidized.
In response to spontaneous overfeeding on a mixed 'cafeteria diet', excess carbohydrate intake is oxidized, suggesting a physiological control of carbohydrate stores, whereas excess fat intake is channeled toward fat stores. None of the observed changes were related to indices of obesity.
研究肥胖与随意进食量（数量和构成）之间的关系，并评估随意进食对能量消耗和常量营养素氧化的影响。
男性志愿者首先食用维持体重的饮食至少4天，然后在接下来的5天里从两台电脑控制的自动售货机中选择食物，这些售货机提供各种常见的、美味的食物。在每个维持体重期和随意进食期的最后一天，在呼吸室内测量24小时能量消耗（24EE）和底物氧化。
代谢研究病房，为期十天的住院。
34名非糖尿病皮马印第安男性，涵盖广泛的体重和身体组成范围（30±8岁，102.1±30.2千克，体脂34±9%，均值±标准差）。
维持体重所需的平均能量为2913±342千卡/天。随意进食期间的能量摄入量增加到4550±921千卡/天（12±1%蛋白质，40±4%脂肪，48±4%碳水化合物），即比维持体重所需的能量自发过量进食54±32%，导致体重增加0.9±1.0千克。所选饮食的构成和过量进食的程度均与身体特征如体重和身体组成无关。与基线相比，第5天的自发过量进食与24EE增加396±233千卡/天、碳水化合物氧化增加607±503千卡/天、脂质氧化减少214±392千卡/天相关（P<0.01），蛋白质氧化无变化。碳水化合物氧化增加与过量碳水化合物摄入量相关（r=0.69，P=0.0001），占过量部分的68±13%（均值±标准误），而过量脂肪摄入未被氧化。
对于混合的“自助餐厅饮食”中的自发过量进食，过量的碳水化合物摄入被氧化，表明对碳水化合物储存存在生理控制，而过量的脂肪摄入则被导向脂肪储存。观察到的变化均与肥胖指标无关。
