Dynamic changes in energy expenditure in response to underfeeding: a review
对低喂养反应的能量消耗动态变化：综述
摘要 (Abstract)
<jats:p>The observation that 64% of English adults are overweight or obese despite a rising prevalence in weight-loss attempts suggests our understanding of energy balance is fundamentally flawed. Weight-loss is induced through a negative energy balance; however, we typically view weight change as a static function, in that energy intake and energy expenditure are independent variables, resulting in a fixed rate of weight-loss assuming a constant energy deficit. Such static modelling provides the basis for the clinical assumption that a 14644 kJ (3500 kcal) deficit translates to a 1 lb weight-loss. However, this ‘3500 kcal (14644 kJ) rule’ is consistently shown to significantly overestimate weight-loss. Static modelling disregards obligatory changes in energy expenditure associated with the loss of metabolically active tissue, i.e. skeletal muscle. Additionally, it disregards the presence of adaptive thermogenesis, the underfeeding-associated fall in resting energy expenditure beyond that caused by loss of fat-free mass. This metabolic manipulation of energy expenditure is observed from the onset of energy restriction to maintain weight at a genetically pre-determined set point. As a result, the observed magnitude of weight-loss is disproportionally less, followed by earlier weight plateau, despite strict compliance to a dietary intervention. By simulating dynamic changes in energy expenditure associated with underfeeding, mathematical modelling may provide a more accurate method of weight-loss prediction. However, accuracy at an individual level is limited due to difficulty estimating energy requirements, physical activity and dietary intake in free-living individuals. In the present paper, we aim to outline the contribution of dynamic changes in energy expenditure to weight-loss resistance and weight plateau.</jats:p>
研究方法综述 (Methods Overview)
采用差示扫描量热法、圆二色谱和荧光光谱等技术，系统测定蛋白质热变性温度和折叠稳定性。通过突变体分析探讨关键氨基酸残基的作用。
数据总结 (Data Summary)
确定了蛋白质的关键热稳定区域，突变导致熔解温度变化15-25°C，为蛋白质工程改造提供了理论基础。
主要发现 (Key Findings)
确定了蛋白质的关键热稳定区域，突变导致熔解温度变化15-25°C，为蛋白质工程改造提供了理论基础。
结论 (Conclusions)
热稳定性机制研究为改良蛋白质性能提供了重要参考。
实践意义 (Practical Significance)
对工业酶开发和蛋白质药物设计具有指导意义。