Miles C W, Wong N P, Rumpler W V, Conway J
United States Department of Agriculture, Beltsville Human Nutrition Research Center, MD 20705.
Eur J Clin Nutr. 1993 Apr;47(4):274-84.
Thermic effect of food (TEF) studies give conflicting answers to research questions and in many cases data from one laboratory to another is not comparable because of the utilization of different experimental methods. Likewise, how weight reduction affects measurement of TEF is controversial. Two studies were conducted on how TEF affects energy expenditure. The first study examined how resting energy expenditure (REE) measurements can affect TEF studies and how much within-subject variation is found in TEF studies. The TEF of a standard meal was measured in six subjects for 6.5 h on three different occasions by indirect calorimetry. REE was measured on each subject for 1 h before the meal was given on each measurement occasion. On a separate day, the energy expenditure was measured on each subject during the same time period as the TEF measurement, but without any food given to determine if a circadian increase in REE over the time period of the measurement was observed. We found no circadian increase in energy expenditure during the 6.5 h of the REE study. While the within-subject variation in REE (four measurements) had an average coefficient of variation of 5.2% (range 2.4-8.5%), the coefficient of variation of the TEF measured (three measurements) was 26.4% (range 13.6-50.9). In the second study, REF and the TEF were measured before and after weight reduction in moderately overweight adult women. Nine women weighing between 62.1 and 84.7 kg lost an average of 7.3 kg while on a reduced calorie, low fat diet for between 12 and 14 weeks. After weight reduction, the average REE of these subjects decreased by 8.8% or 515 kJ (123 kcal)/24 h. The TEF of these nine women was measured for 6.5 h before and after weight reduction using 16 oz of Sustacal, 2008 kJ (480 kcal). Before weight reduction the thermic effect of Sustacal was 264 kJ (63 kcal) or 13% of calories consumed, and after weight reduction it was 251 kJ (60 kcal) or 12.5% of calories consumed. We did not find the TEF to be lower than expected in these subjects before weight reduction, since TEF is often reported to be around 10% of energy consumed, and it was not changed after weight reduction.
食物热效应（TEF）研究对研究问题给出了相互矛盾的答案，而且在很多情况下，由于采用了不同的实验方法，不同实验室的数据无法进行比较。同样，体重减轻如何影响TEF的测量也存在争议。我们进行了两项关于TEF如何影响能量消耗的研究。第一项研究考察了静息能量消耗（REE）测量如何影响TEF研究，以及在TEF研究中受试者内部的变异程度。通过间接测热法，在三个不同的时间段，对六名受试者进行了6.5小时的标准餐TEF测量。在每次测量时，于用餐前1小时对每名受试者测量REE。在另一天，在与TEF测量相同的时间段内，对每名受试者测量能量消耗，但不给予任何食物，以确定在测量时间段内是否观察到REE的昼夜节律性增加。我们发现在REE研究的6.5小时内，能量消耗没有昼夜节律性增加。虽然REE（四次测量）的受试者内部变异的平均变异系数为5.2%（范围为2.4 - 8.5%），但测量的TEF（三次测量）的变异系数为26.4%（范围为13.6 - 50.9%）。在第二项研究中，对中度超重成年女性在体重减轻前后测量了REE和TEF。九名体重在62.1至84.7千克之间的女性，在12至14周的低热量、低脂肪饮食期间平均减重7.3千克。体重减轻后，这些受试者的平均REE下降了8.8%或515千焦（123千卡）/24小时。使用16盎司的苏太卡尔（Sustacal，2008千焦，480千卡），在体重减轻前后对这九名女性的TEF进行了6.5小时的测量。体重减轻前，苏太卡尔的热效应为264千焦（63千卡），占摄入热量的13%，体重减轻后为251千焦（60千卡），占摄入热量的12.5%。我们没有发现这些受试者在体重减轻前的TEF低于预期，因为通常报道TEF约为摄入能量的10%，且体重减轻后TEF没有变化。
