MRC Human Nutrition Research, Cambridge, UK.
Int J Obes (Lond). 2010 May;34(5):908-18. doi: 10.1038/ijo.2010.9. Epub 2010 Feb 9.
The cellular model of body composition divides the body in body cell mass (BCM), extracellular solids and extracellular fluids. This model has been infrequently applied for the evaluation of weight loss (WL) programmes.
(1) To assess changes in body compartments in obese men undergoing fasting, very low calorie diet (VLCD) and low calorie diet (LCD); (2) to evaluate two cellular models for the determination of changes in BCM, fat mass (FM) and body fluids.
Three groups of six, obese men participated in a total fast (F) for 6 days, a VLCD (2.5 MJ per day) for 3 weeks or an LCD (5.2 MJ per day) for 6 weeks. Body composition was measured at baseline and after small ( approximately 5%) and moderate ( approximately 10%) WL. FM was measured using a four-compartment model. Total body water (TBW) and extracellular water (ECW) were, respectively, measured by deuterium and sodium bromide dilution and intracellular water (ICW) calculated by difference. Two cellular models were used to measure BCM, FM and body fluids distribution.
After about 5%WL changes in TBW were F=-3.2+/-1.2 kg (P<0.01), VLCD=-1.2+/-0.6 kg (P<0.01), LCD=-0.3+/-0.9 kg(n.s.). The contribution of TBW to total body mass loss was indirectly associated with FM loss. ECW increased during fasting (+1.5+/-3.1 kg, n.s.), decreased during the VLCD (-2.0+/-1.5 kg, P<0.05) and remained unchanged at the end of the LCD (-0.3+/-1.6 kg, n.s.). ICW significantly decreased during fasting (-4.7+/-3.9 kg, P<0.05) but did not change in the LCD and VLCD groups. The loss of BCM was more significant in the fasting group and it was directly associated with changes in ICW.
After a 6-day period of fasting we observed more ICW losses and less fat mobilization compared with VLCD and LCD. The cellular model of body composition is suitable for the characterization of changes in body fluids distribution during WL.
人体成分的细胞模型将人体分为身体细胞质量（BCM）、细胞外固体和细胞外液。该模型很少用于评估减肥（WL）计划的效果。
（1）评估肥胖男性在禁食、极低热量饮食（VLCD）和低热量饮食（LCD）期间身体各部位的变化；（2）评估两种细胞模型，用于确定 BCM、脂肪量（FM）和体液的变化。
三组各有 6 名肥胖男性参加了为期 6 天的完全禁食（F）、为期 3 周的 VLCD（每天 2.5 兆焦耳）或为期 6 周的 LCD（每天 5.2 兆焦耳）。在基线和小（约 5%）和中等（约 10%）WL 后测量身体成分。FM 使用四室模型测量。通过氘和溴化钠稀释分别测量总身体水（TBW）和细胞外水（ECW），并通过差值计算细胞内水（ICW）。使用两种细胞模型测量 BCM、FM 和体液分布。
WL 约 5%后，TBW 的变化为 F=-3.2+/-1.2kg（P<0.01）、VLCD=-1.2+/-0.6kg（P<0.01）、LCD=-0.3+/-0.9kg（无统计学意义）。TBW 对总体重损失的贡献与 FM 损失间接相关。禁食期间 ECW 增加（+1.5+/-3.1kg，无统计学意义），VLCD 期间减少（-2.0+/-1.5kg，P<0.05），LCD 结束时无变化（-0.3+/-1.6kg，无统计学意义）。禁食期间 ICW 显著下降（-4.7+/-3.9kg，P<0.05），但在 LCD 和 VLCD 组中没有变化。在禁食组中，BCM 的损失更为显著，并且与 ICW 的变化直接相关。
与 VLCD 和 LCD 相比，在为期 6 天的禁食期间，我们观察到更多的 ICW 损失和更少的脂肪动员。身体成分的细胞模型适合于描述 WL 期间体液分布的变化。
