Raman Aarthi, Baum Scott T, Colman Ricki J, Kemnitz Joseph W, Weindruch Richard, Schoeller Dale A
Department of Nutritional Sciences, University of Wisconsin, Madison, WI 53706, USA.
Exp Gerontol. 2007 Oct;42(10):988-94. doi: 10.1016/j.exger.2007.05.008. Epub 2007 Jul 6.
Calorie restriction (CR) is a dietary intervention shown to increase maximum life-span. The aim of this study was to compare the metabolizable energy of the pelleted semi-purified diet with estimated energy intake from food weight. Energy density of diet, urine and feces were measured by bomb calorimetry in rhesus monkeys (23-29 years old) on CR (CR, n=11) and control (C, n=9). Food moisture was measured to be 2-fold higher (9+/-1%) than indicated on the label (approximately 5%). The measured gross energy of diet was 4.4 kcal/g dry weight of CR and 4.5 kcal/g dry weight of C diets. In a two-day trial, food intake (mean+/-SD) was 112+/-20 g and 136+/-26 g of dry mass/d in the CR and C monkeys, respectively (p=0.003). The fraction of the diet absorbed (CR=0.91; C=0.95) was different (p<0.001) between CR and C monkeys. Using these coefficients, the metabolizable energy intake averaged over 6 months was 450+/-53 and 534+/-97 kcal/d in CR and C monkeys, respectively (Diff=16%; p=0.03). These values were compared with energy expenditure (EE), as measured annually by indirect calorimetry (490+/-61 kcal/d in CR and 532+/-62 kcal/d in C monkeys). Adjusted for changes in body composition (2+/-10 kcal/d in CR and -7+/-12 kcal/d in C), energy balance was not different from zero in CR (-42+/-42 kcal/d) and C (9+/-61 kcal/d) monkeys. Use of diet weight is a reasonable estimate of the level of CR when food waste is assessed.
热量限制（CR）是一种已被证明可延长最大寿命的饮食干预措施。本研究的目的是比较颗粒状半纯化饮食的可代谢能量与根据食物重量估算的能量摄入量。通过弹式量热法测量了恒河猴（23 - 29岁）在热量限制组（CR，n = 11）和对照组（C，n = 9）中饮食、尿液和粪便的能量密度。测得食物的水分含量比标签上标注的（约5%）高出2倍（9±1%）。测得的CR组饮食干重的总能为4.4千卡/克，C组饮食干重的总能为4.5千卡/克。在为期两天的试验中，CR组和C组猴子的食物摄入量（均值±标准差）分别为112±20克和136±26克干物质/天（p = 0.003）。CR组和C组猴子之间饮食的吸收比例不同（CR = 0.91；C = 0.95，p < 0.001）。利用这些系数，CR组和C组猴子在6个月内的平均可代谢能量摄入量分别为450±53千卡/天和534±97千卡/天（差异 = 16%；p = 0.03）。将这些值与每年通过间接量热法测得的能量消耗（EE）进行比较（CR组猴子为490±61千卡/天，C组猴子为532±62千卡/天）。根据身体成分的变化进行调整（CR组为2±10千卡/天，C组为 - 7±12千卡/天）后，CR组（ - 42±42千卡/天）和C组（9±61千卡/天）猴子的能量平衡与零无差异。在评估食物浪费情况时，使用饮食重量是对热量限制水平的合理估计。
