HEREDITY: OVERFEEDING AND EXERCISE

这些研究旨在检验观察到的个体差异 在对过度进食或有氧运动的反应中， 与遗传有关。两个主要的实验将分别在12对 成年男性单卵(MZ)双胞胎。试验性治疗将持续下去 每种情况下都是100天，在此之前将进行一周的观察 确定身体成分、习惯性能量摄入量、能量消耗 习惯性活动和其他参数。在第一个实验中，两组 每对MZ的成员将接受过量喂养的治疗 比他们习惯的能量摄入量多1000千卡/天。在第二个 实验所有双胞胎都将处于1000的负能量平衡状态 通过一项运动计划诱导的千卡/天。这两种情况下的治疗都将是 连续使用6天，然后休息一天。变化 在身体密度、全身脂肪、皮下四肢和躯干脂肪方面， 脂肪细胞大小与脂肪细胞脂解、脂肪生成和脂蛋白脂酶 两个活检点(髂上和股骨)的活动性、血脂 和脂蛋白，静息代谢率，饮食诱导的产热， 运动耐量、葡萄糖耐量及其相关的血糖， 胰岛素、高血糖素、儿茶酚胺和甲状腺激素的变化 促甲状腺激素释放激素对促甲状腺激素的反应性将被研究 治疗前和治疗后100天以及治疗25天和50天后 几天。所有饮食都将是混合型，碳水化合物含量约为50%-35% 脂肪，15%蛋白质。有氧运动计划将是适度的 强度(从最大心率储备的40%到70%)和足够 持续时间，以满足研究的能源成本要求。这些 实验将允许量化平均响应和 个体间对过度喂养或有氧运动训练的差异。 还将分析配对内部的相似性和配对之间的差异 以确定治疗带来的适应性变化是否 取决于或独立于个体的基因型别。此外， 这项研究将使短期适应性的比较成为可能 随着后来的适应而变化，并测试是否 随着时间推移的反应是由基因决定的。这些研究的结果 应该可以解释一些不明原因的身体成分和 在减肥和增重过程中观察到新陈代谢。

These studies are designed to test whether individual differences observed in the response to overfeeding or aerobic exercise-training are associated with heredity. Two major experiments will be conducted each on 12 pairs of adult male monozygotic (MZ) twins. The experimental treatment will last for 100 days, in each case, and will be preceeded by a week of observation to establish body composition, habitual energy intake, energy cost of habitual activities and other parameters. In the first experiment, both members of each MZ pair will be submitted to an overfeeding treatment of an extra 1000 kcal/day over their habitual energy intake. In the second experiment all twins will be submitted to a negative energy balance of 1000 kcal/day induced by a program of exercise. Treatment in both cases will be applied in cycles of 6 consecutive days followed by a day of rest. Changes in body density, total body fat, subcutaneous extremity and trunk fatness, fat cell size and fat cell lipolysis, lipogenesis and lipoprotein lipase activity from two sites of biopsy (suprailiac and femoral), blood lipids and lipoproteins, resting metabolic rate, diet induced thermogenesis, exercise tolerance, glucose tolerance and their associated blood glucose, insulin, glucagon, catecholamines and thyroid hormones variations and the thyrotropes responsiveness to thyrotropin releasing hormone will be studied before and after the 100 days of treatment as well as after 25 and 50 days. All diets will be of the mixed type with about 50% carbohydrate, 35% fat, 15% protein. The aerobic exercise program will be of moderate intensity (from 40% to 70% of maximal heart rate reserve) and of sufficient duration to meet the energy cost requirement of the study. These experiments will allow the quantification of the mean response and of the inter-individual differences to overfeeding or aerobic exercise-training. Within pair resemblance and between pairs variation will also be analyzed to establish whether the adaptive changes brought about by the treatments are dependent or independent of the genotype of the individuals. Moreover, the research will make possible the comparison of short term adaptive changes with later adaptations and to test whether the pattern of the response over time is genetically determined. Results of these studies should explain some of the unaccounted variations in body composition and metabolism observed during weight reduction and weight gain.