DIETARY FAT, CARBOHYDRATE BALANCE & WEIGHT MAINTENANCE

糖原储存可能在相当低或相当高的平均水平附近波动 水平，作为代谢适应的一部分，允许碳水化合物 氧化程度与饮食中碳水化合物的含量相称。 的 将要检验的假设是扩大或缩小 脂肪组织质量也代表和适应，影响游离脂肪 酸水平，直到脂肪氧化按百分比与 特定饮食的脂肪含量。 长期维持体重就可以了 由于维持碳水化合物的普遍能力而得以实现 通过食物摄入与碳水化合物氧化的相互调节来达到平衡 反之亦然。 但是，尽管糖原储存的变化几乎不会影响身体 体重；脂肪组织质量的改变可导致肥胖。 在这里可以找到一个简单的解释： 富裕社会中消费“混合”饮食的肥胖率相对较高 脂肪含量高。 饮食脂肪含量与稳态的关系 将通过对适应的小鼠的尸体分析来研究脂肪组织量 蛋白质固定但碳水化合物和脂肪含量可变的饮食（12 83% 卡路里为脂肪）。 实验旨在揭示 这种关系是否是渐进的和可逆的 证实饮食引起的肥胖变化的适应性。 一些 动物将被饲养在密封的室内，每 24 小时通风一次 小时，以测量其 O2 消耗量和 CO2 产量。 结合 测量营养摄入量（针对溢出和不完整进行校正 吸收）这将允许计算动物每日的变化 碳水化合物和脂肪含量。 这些数据将有助于确定如何 准确地维持碳水化合物、脂肪和能量平衡 随意进食的情况，并检查是否以及如何进食 摄入量可能会根据动物的增益或损失而改变 糖原和/或脂肪储备。 拟议调查的总体目标是证明 膳食脂肪含量对稳态身体成分的影响。 最终，这可能会引发代谢争论（除了 那些基于热量密度的）表明减少 饮食中的脂肪含量可能有助于将体重维持在较低水平 肥胖。

Glycogen stores may fluctuate around rather low or rather high average levels, as part of the metabolic adaptation permitting carbohydrate oxidation to be commensurate with the diets corbohydrate contents. The hypothesis which will be tested is that an expansion or reduction of the adipose tissue mass also represents and adaptation, influencing free-fatty acid levels until fat oxidation becomes commensurate, percentage-wise, with a particular diet's fat content. Long-term weight maintenance would then be achieved thanks to the ubiquitous ability for maintaining carbohydrate balance by mutual adjustment of food intake to carbohydrate oxidation and vice-versa. But whereas changes in the glycogen stores hardly affect body weight;, alterations of the adipose tissue mass can lead to obesity. Herein could be found a simple explanation for the high incidence of obesity in affluent societies consuming "mixed" diets with a relatively high-fat content. The relationship between the fat content of the diet and the steady-state adipose tissue mass will be studied by carcass analysis of mice adapted to diets with a fixed protein, but variable carbohydrate and fat contents (12 to 83 percent calories as fat). The experiments will be designed to reveal whether this relationship is progressive and reversible, which would confirm the adaptive nature of diet-induced changes in adiposity. Some animals will be kept in hermetically sealed chambers, vented once every 24 hours, to measure their O2 consumption and CO2 production. In conjunction with measurements of nutrient intake (corrected for spillage and incomplete absorption) this will allow to calculate daily changes in the animals' carbohydrate and fat contents. Such data will allow to determine how accurately the carbohydrate, fat and energy balances are maintained under ad libitum food intake conditions, and to examine whether and how food intake may be altered in response to gains, or losses in the animal's glycogen and/or fat reserves. The general goal of the proposed investigations is to demonstrate the impact of the dietary fat content on steady-state body composition. Ultimately this may allow to develop metabolic arguments (in addition to those based on caloric density) suggesting that a reduction in the diets'fat content may facilitate weight maintenance at a lower level of adiposity.