Department of Medicine, College of Physicians & Surgeons, Columbia University, New York, NY, USA.
Brain Res. 2010 Sep 2;1350:95-102. doi: 10.1016/j.brainres.2010.05.062. Epub 2010 Jun 2.
Almost anyone who has ever lost weight can attest that it is harder to sustain weight loss than to lose weight. Maintenance of a 10% or greater reduced body weight is accompanied by decreases in energy expenditure to levels significantly below what is predicted solely on the basis of weight and body composition changes. This disproportionate decline in energy expenditure would not be sufficient to account for the over 80% recidivism rate to pre-weight loss levels of body fatness after otherwise successful weight reduction if there were a corresponding reduction in energy intake. In fact, reduced body weight maintenance is accompanied by increased energy intake above that required to maintain reduced weight. The failure to reduce energy intake in response to decreased energy output reflects decreased satiation and perception of how much food is eaten and multiple changes in neuronal signaling in response to food which conspire with the decline in energy output to keep body energy stores (fat) above a CNS-defined minimum (threshold). Much of this biological opposition to sustained weight loss is mediated by the adipocyte-derived hormone "leptin."
几乎每个曾经减肥的人都可以证明，保持体重减轻比减肥更难。维持体重减轻 10%或更多会伴随着能量消耗的减少，其水平明显低于仅根据体重和身体成分变化预测的水平。如果能量摄入相应减少，那么这种不成比例的能量消耗下降不足以解释超过 80%的人在成功减肥后体重恢复到减肥前的体脂水平。事实上，体重减轻后，能量摄入会增加，超过维持减轻体重所需的量。未能根据能量输出的减少来减少能量摄入，反映了饱腹感的降低以及对所吃食物量的感知，以及神经元信号对食物的多种变化，这些变化与能量输出的下降一起，使身体的能量储存（脂肪）保持在中枢神经系统定义的最小值（阈值）以上。这种对持续减肥的生物学抵抗在很大程度上是由脂肪细胞衍生的激素“瘦素”介导的。
