DIETARY FAT, CARBOHYDRATE BALANCE AND WEIGHT MAINTENANCE

当饮食提供了足够的蛋白质，体重维持是 主要是由参与相互作用的现象， 碳水化合物和脂肪的摄入和氧化。 的条件 碳水化合物和脂肪的平衡必须达到显着不同，因为 人体储存糖原和脂肪的能力是 大小分开。 本项目的目的是研究 这种差异必然会产生，不仅是在监管方面， 新陈代谢及其对食物摄入的反馈，而且还影响身体 混合物. 通过结合营养素摄入量和24小时呼吸的测量， 交换保存在大的密封桶（通风的）中的小鼠 每天一次），测定动物的碳水化合物和脂肪平衡 每天都在长时间。 这些数据将允许检查哪些 食物摄入量的程度变化可能反映了“纠正反应”倾向 以补偿动物在其活动中所遭受的损失或收益。 糖原、脂肪和/或能量储备，以及 认识到其中哪些似乎是最重要的长期 当食物自由供应时，体重维持。 当饮食中含有 相对高比例的脂肪被消耗， 脂肪组织质量似乎往往是必要的贡献之前， 脂肪的代谢燃料混合氧化成为相称的 饮食的脂肪含量。 这可能与不平等有关。 饮食中碳水化合物和脂肪对新陈代谢的影响也会影响 体重的调节。 这一现象将由 测定小鼠体、肝蛋白质、脂肪和糖原含量 自由采食配制的饲料， 脂肪和碳水化合物的比例 拟议调查的主要目标是确定影响的特征 饮食中的脂肪含量对稳态身体成分的影响， 描述碳水化合物、脂肪和能量的相对重要性 控制食物摄入的平衡。 随着时间的推移，这可能会使开发 代谢参数（除了目前的建议， 考虑热量密度），以解释为什么减少饮食的 脂肪含量可有助于在较低的肥胖水平下维持体重。

When the diet provides more than enough protein, weight maintenance is primarily determined by the phenomena involved in the interplay between intake and oxidation of carbohydrates and fats. The conditions under which carbohydrate and fat balances must be achieved differ markedly, because the body's storage capacities for glycogen and for fat are two orders of magnitude apart. The aim of this project is to examine the implications which this difference is bound to have, not only on the regulation of metabolism and its feed-back on food intake, but also in influencing body composition. By combining measurements of nutrient intake and of the 24-h respiratory exchange of mice maintained in large, hermetically sealed drums (vented once a day), the animals' carbohydrate and fat balances will be determined daily over prolonged periods. The data will permit to examine to which extent variations in food intake may reflect "corrective responses" tending to compensate for gains of losses incurred by the animals in their glycogen, fat and/or energy reserves during the preceeding day(s), and to recognize which of these appear to be the most significant for long-term weight maintenance when food is freely available. When diets containing relatively high proportions of fat are consumed, an expansion of the adipose tissue mass appears to be often necessary before the contribution of fat to the metabolic fuel mix oxidized becomes commensurate with the diets' fat content. This may be related to the fact that the unequal impact which dietary carbohydrate and fat have on metabolism also affects the regulation of body weight. This phenomenon will be examined by measuring the body and liver contents of protein fat and glycogen in mice maintained ad libitum on diets formulated to contain gradual increments in the fat-to-carbohydrate ratio. The main goal of the proposed investigations is to characterize the impact of the diet's fat content on steady-state body composition, and to delineate the relative importance of the carbohydrate, fat, and energy balances in the control of food intake. In time, this may allow to develop metabolic arguments (in addition to the current recommendations based on consideration of caloric density), to explain why a reduction in the diet's fat content may facilitate weight maintenance at a lower level of adiposity.