Stubbs R J, Johnstone A M, O'Reilly L M, Barton K, Reid C
The Rowett Research Institute, Bucksburn, Aberdeen, UK.
Int J Obes Relat Metab Disord. 1998 Oct;22(10):980-7. doi: 10.1038/sj.ijo.0800715.
This study examined the effects of covert alterations in the energy density (ED) of mixed, medium fat (MF) diets on ad libitum food and energy intake (EI), subjective hunger and body weight in humans.
Randomised cross-over design. Subjects were each studied three times (factorial design), during 14d, throughout which they had ad libitum access to one of three covertly-manipulated MF diets.
Six healthy men, mean age (s.e.m.) = 30.0 y (12.76 y), mean weight = 71.67 kg (19.80 kg); mean height = 1.79 m (0.22 m), body mass index (BMI) = 22.36 (2.60) kg/m2, were studied. The fat, carbohydrate (CHO) and protein in each diet (as a proportion of the total energy) and energy density (ED) were, low-ED (LED), 38:49:13%; 373 kJ/100 g; medium-ED (MED), 40:47:13%; 549 kJ/100 g; high-ED (HED), 39:48:13%; 737 kJ/100 g. Subjects could alter the amount but not the composition of foods eaten. They were resident in (but not confined to) a metabolic suite throughout the study.
Solid food intake decreased as ED increased, giving mean values of 2.84, 2.51 and 2.31 kg/d, respectively. This was insufficient to defend energy balance, since energy intake increased with increasing ED (F(2,10) 16.08; P < 0.001) giving mean intakes of 10.12, 12.80 and 16.17 MJ/d, respectively. Rated pleasantness of food (measured on visual analogue scales) was not significantly different between diets nor was subjective hunger different between the LED, MED and HED diets, respectively. Diet significantly affected body weight (F(2,10) = 4.62; P = 0.038), producing changes of -1.20, 0.02 and 0.95 kg, respectively, by day 14.
Dietary ED can influence EI and body weight, since changes in amount eaten alone are insufficient to defend energy balance, when subjects feed on unfamiliar diets and diet selection is precluded. Comparison with our previous studies suggest that there was compensation in solid food intake when ED was altered using mixed diets (as in this study) compared to previous studies which primarily used fat or CHO to alter dietary ED.
本研究探讨了混合中等脂肪（MF）饮食的能量密度（ED）隐性改变对人类随意食物摄入量和能量摄入量（EI）、主观饥饿感及体重的影响。
随机交叉设计。在14天内，每位受试者接受三次研究（析因设计），在此期间他们可随意获取三种经隐性操控的MF饮食中的一种。
研究了6名健康男性，平均年龄（标准误）=30.0岁（12.76岁），平均体重=71.67千克（19.80千克）；平均身高=1.79米（0.22米），体重指数（BMI）=22.36（2.60）千克/平方米。每种饮食中的脂肪、碳水化合物（CHO）和蛋白质（占总能量的比例）以及能量密度（ED）分别为：低能量密度（LED），38:49:13%；373千焦/100克；中等能量密度（MED），40:47:13%；549千焦/100克；高能量密度（HED），39:48:13%；737千焦/100克。受试者可改变所吃食物的量，但不能改变其成分。在整个研究过程中，他们居住在（但不限于）代谢套房内。
随着能量密度增加，固体食物摄入量减少，平均值分别为2.84、2.51和2.31千克/天。这不足以维持能量平衡，因为能量摄入量随着能量密度增加而增加（F(2,10)=16.08；P<0.001），平均值分别为10.12、12.80和16.17兆焦/天。食物的评定愉悦度（用视觉模拟量表测量）在不同饮食之间无显著差异，LED、MED和HED饮食之间的主观饥饿感也无差异。饮食对体重有显著影响（F(2,10)=4.62；P=0.038），到第14天体重分别变化-1.20、0.02和0.95千克。
饮食能量密度可影响能量摄入量和体重，因为当受试者食用不熟悉的饮食且无法进行饮食选择时，仅食物摄入量的变化不足以维持能量平衡。与我们之前的研究相比，表明与主要使用脂肪或碳水化合物来改变饮食能量密度的先前研究相比，当使用混合饮食（如本研究）改变能量密度时，固体食物摄入量存在补偿现象。
