School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
J Am Coll Nutr. 2010 Aug;29(4):343-51. doi: 10.1080/07315724.2010.10719850.
The search for the causes of obesity has involved genetic abnormalities and endocrine and neural lesions. Although evidence suggests that genetics plays an important role in body weight regulation, rapid increases in obesity rates do not seem to be caused by significant genetic changes within populations. Total energy expenditure and total energy intake are not the only factors that regulate body fat. Nitrogen and carbohydrate balances are eased by the capacity of the organism for adjusting amino acids and glucose oxidation rates, respectively. Regarding fat, this mechanism is considerably less precise; a fat intake increase does not stimulate its oxidation on the same basis. In addition, dietary fat is stored very efficiently as body fat. Elevated carbohydrate ingestion enhances glycogen reserves, which usually are much smaller than the maximum capacity of storage and enlargement of these stores, thus stimulating this nutrient's oxidation. These data point to a very well controlled carbohydrate balance in the body. Various studies show lack of efficiency of the hyperlipidic diet in stimulating satiety. Signals arising from the gastrointestinal tract play a fundamental role in regulation of appetite and energy intake, and evidence indicates that the gastrointestinal and hormonal mechanisms involved in the suppression of appetite and in energy intake are compromised in obesity. A high-fat diet is important in its origin. Additional studies are necessary to explain the mechanisms that lead to adipose tissue retention resulting in a fat-rich diet.
肥胖病因的研究涉及遗传异常、内分泌和神经损伤。尽管有证据表明遗传在体重调节中起重要作用，但肥胖率的快速增长似乎并不是由于人群中发生重大遗传变化引起的。总能量消耗和总能量摄入并不是调节体脂的唯一因素。氮和碳水化合物的平衡分别通过机体调节氨基酸和葡萄糖氧化率的能力得以缓解。至于脂肪，这种机制则不那么精确；脂肪摄入的增加并不会以同样的基础刺激其氧化。此外，膳食脂肪作为体脂储存非常有效。碳水化合物摄入的增加会增强糖原储备，而糖原储备通常远小于储存和扩大这些储备的最大能力，从而刺激这种营养素的氧化。这些数据表明，体内的碳水化合物平衡得到了很好的控制。各种研究表明高脂饮食在刺激饱腹感方面效率低下。来自胃肠道的信号在调节食欲和能量摄入方面起着至关重要的作用，有证据表明，涉及抑制食欲和能量摄入的胃肠道和激素机制在肥胖症中受到了损害。高脂肪饮食在其起源中很重要。需要进一步的研究来解释导致脂肪组织保留从而导致富含脂肪的饮食的机制。
