Weinsier R L, Hunter G R, Heini A F, Goran M I, Sell S M
Department of Nutrition Sciences, University of Alabama at Birmingham, 35294, USA.
Am J Med. 1998 Aug;105(2):145-50. doi: 10.1016/s0002-9343(98)00190-9.
Three major factors modulate body weight: metabolic factors, diet, and physical activity, each influenced by genetic traits. Despite recent advances in these areas, the prevalence of obesity in Westernized societies has increased. In contrast to monogenic animal models and rare human genetic syndromes, predisposition to common forms of obesity is probably influenced by numerous susceptibility genes, accounting for variations in energy requirements, fuel utilization, muscle metabolic characteristics, and taste preferences. Although recent increases in obesity prevalence cannot be explained by changes in the gene pool, previously "silent" genetic variants may now play important permissive roles in modern societies. Available data suggest that variations in resting energy expenditure, thermic effect of food, and fuel utilization exist but, by themselves, are unlikely to explain the onset of obesity. Regarding diet, the best available trend survey data indicate that fat and energy intake have fallen, in this and other Westernized countries. Diverging trends of decreasing energy intake and increasing body weight suggest that reduced physical activity may be the most important current factor explaining the rising prevalence of obesity. Subsistence in modern societies requires extreme adaptations in previously useful energy-conserving diet and exercise behaviors. Recognizing the difficulties in sustaining energy-restricted diets in the presence of fast foods and social feasts, the current trend toward increasing body weight is not likely to be reversed solely through recommendations for further reductions in energy intake. In all likelihood, activity levels will have to increase in response to an environment engineered to be more physically demanding.
代谢因素、饮食和体力活动，每一个因素都受遗传特征影响。尽管这些领域最近取得了进展，但西方化社会中肥胖症的患病率仍在上升。与单基因动物模型和罕见的人类遗传综合征不同，常见肥胖形式的易感性可能受众多易感基因影响，这些基因导致能量需求、燃料利用、肌肉代谢特征和口味偏好存在差异。虽然最近肥胖症患病率的上升不能用基因库的变化来解释，但以前“沉默”的基因变异现在可能在现代社会中发挥重要的促成作用。现有数据表明，静息能量消耗、食物热效应和燃料利用存在差异，但仅凭这些差异不太可能解释肥胖症的发生。关于饮食，现有的最佳趋势调查数据表明，在这个国家和其他西方化国家，脂肪和能量摄入量已经下降。能量摄入减少和体重增加的不同趋势表明，体力活动减少可能是目前解释肥胖症患病率上升的最重要因素。现代社会的生存需要对以前有益的节能饮食和运动行为进行极端调整。认识到在有快餐和社交宴会的情况下维持能量限制饮食的困难，目前体重增加的趋势不太可能仅通过进一步减少能量摄入的建议来扭转。很有可能，活动水平将不得不随着设计得对身体要求更高的环境而增加。
