Das Sai Krupa, Roberts Susan B, McCrory Megan A, Hsu L K George, Shikora Scott A, Kehayias Joseph J, Dallal Gerard E, Saltzman Edward
Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
Am J Clin Nutr. 2003 Jul;78(1):22-30. doi: 10.1093/ajcn/78.1.22.
Little is known about the determinants of individual variability in body weight and fat loss after gastric bypass surgery or about the effects of massive weight loss induced by this surgery on energy requirements.
The objectives were to determine changes in energy expenditure and body composition with weight loss induced by gastric bypass surgery and to identify presurgery predictors of weight loss.
Thirty extremely obese women and men with a mean (+/- SD) age of 39.0 +/- 9.6 y and a body mass index (BMI; in kg/m(2)) of 50.1 +/- 9.3 were tested longitudinally under weight-stable conditions before surgery and after weight loss and stabilization (14 +/- 2 mo). Total energy expenditure (TEE), resting energy expenditure (REE), body composition, and fasting leptin were measured.
Subjects lost 53.2 +/- 22.2 kg body weight and had significant decreases in REE (-2.4 +/- 1.0 MJ/d; P < 0.001) and TEE (-3.6 +/- 2.5 MJ/d; P < 0.001). Changes in REE were predicted by changes in fat-free mass and fat mass. The average physical activity level (TEE/REE) was 1.61 at both baseline and follow-up (P = 0.98). Weight loss was predicted by baseline fat mass and BMI but not by any energy expenditure variable or leptin. Measured REE at follow-up was not significantly different from predicted REE.
TEE and REE decreased by 25% on average after massive weight loss induced by gastric bypass surgery. REE changes were predicted by loss of body tissue; thus, there was no significant long-term change in energy efficiency that would independently promote weight regain.
关于胃旁路手术后个体体重和脂肪减少的决定因素，以及该手术导致的大量体重减轻对能量需求的影响，我们所知甚少。
本研究旨在确定胃旁路手术导致体重减轻时能量消耗和身体成分的变化，并找出术前体重减轻的预测因素。
对30名极度肥胖的女性和男性进行纵向测试，他们的平均（±标准差）年龄为39.0±9.6岁，体重指数（BMI；单位：kg/m²）为50.1±9.3。在手术前、体重减轻并稳定后（14±2个月）的体重稳定条件下进行测试。测量了总能量消耗（TEE）、静息能量消耗（REE）、身体成分和空腹瘦素。
受试者体重减轻了53.2±22.2千克，REE显著降低（-2.4±1.0兆焦/天；P<0.001），TEE也显著降低（-3.6±2.5兆焦/天；P<0.001）。REE的变化可由去脂体重和脂肪量的变化预测。基线和随访时的平均身体活动水平（TEE/REE）均为1.61（P = 0.98）。体重减轻可由基线脂肪量和BMI预测，但不能由任何能量消耗变量或瘦素预测。随访时测得的REE与预测的REE无显著差异。
胃旁路手术导致大量体重减轻后，TEE和REE平均下降了25%。REE的变化可由身体组织的减少预测；因此，能量效率没有显著的长期变化，不会独立促进体重反弹。
