Tappy L, Jéquier E
Institute of Physiology, University of Lausanne, Switzerland.
Am J Clin Nutr. 1993 Nov;58(5 Suppl):766S-770S. doi: 10.1093/ajcn/58.5.766S.
Ingestion of nutrients increases energy expenditure above basal metabolic rate. Thermogenesis of carbohydrate comprises two distinct components: an obligatory component, which corresponds to the energy cost of carbohydrate absorption, processing, and storage; and a facultative component, which appears to be related with a carbohydrate-induced stimulation of the sympathetic nervous system, and can be inhibited by beta-adrenergic antagonists. Fructose ingestion induces a greater thermogenesis than does glucose. This can be explained by the hydrolysis of 3.5-4.5 mol ATP/mol fructose stored as glycogen, vs 2.5 mol ATP/mol glucose stored. Therefore the large thermogenesis of fructose corresponds essentially to an increase in obligatory thermogenesis. Obese individuals and obese patients with non-insulin-dependent diabetes mellitus commonly have a decrease in glucose-induced thermogenesis. These individuals in contrast display a normal thermogenesis after ingestion of fructose. This may be explained by the fact that the initial hepatic fructose metabolism is independent of insulin. This observation indicates that insulin resistance is likely to play an important role in the decreased glucose-induced thermogenesis of these individuals.
摄入营养物质会使能量消耗高于基础代谢率。碳水化合物的产热包括两个不同的部分：一个是 obligatory 部分，它对应于碳水化合物吸收、加工和储存的能量消耗；另一个是 facultative 部分，它似乎与碳水化合物诱导的交感神经系统刺激有关，并且可以被β-肾上腺素能拮抗剂抑制。摄入果糖比摄入葡萄糖诱导产生更大的产热。这可以通过每摩尔果糖以糖原形式储存水解3.5 - 4.5摩尔ATP来解释，而每摩尔葡萄糖储存水解2.5摩尔ATP。因此，果糖的大量产热基本上对应于 obligatory 产热的增加。肥胖个体和患有非胰岛素依赖型糖尿病的肥胖患者通常葡萄糖诱导的产热会减少。相比之下，这些个体在摄入果糖后产热正常。这可能是因为最初肝脏果糖代谢不依赖胰岛素。这一观察结果表明胰岛素抵抗可能在这些个体葡萄糖诱导的产热减少中起重要作用。
