HEREDITY--OVERFEEDING AND EXERCISE

这些研究旨在测试是否观察到个体差异 在对过度喂养或有氧运动训练的反应中， 与遗传有关。 两个主要的实验将分别在12对 成年男性同卵双胞胎。 实验性治疗将持续 在每种情况下，持续100天，并将通过一周的观察来预先确定 建立身体成分，习惯性能量摄入， 习惯性活动和其他参数。 在第一个实验中， 每对MZ的成员将被提交给一个过度喂养的治疗， 每天比平时多摄入1000大卡。 在第二 实验所有双胞胎将提交到负能量平衡1000 kcal/day由锻炼计划引起。 这两种情况的治疗将是 以连续6天为一个周期，然后休息一天。 变化 体密度、全身脂肪、四肢皮下脂肪和躯干脂肪， 脂肪细胞大小和脂肪细胞脂解、脂肪生成和脂蛋白脂酶 两个活检部位（髂上和股）的活动，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血糖， 胰岛素、胰高血糖素、儿茶酚胺和甲状腺激素变化， 将研究促甲状腺激素对促甲状腺激素释放激素的反应性 治疗100天前后以及治疗25天和50天后 天 所有的饮食都是混合型的，碳水化合物约占50%， 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%）和足够的 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 个体间的差异，以过度喂养或有氧运动训练。 对内的相似性和对之间的变化也将进行分析 以确定治疗带来的适应性变化是否 依赖于或不依赖于个体的基因型。 此外，委员会认为， 这项研究将使短期适应性比较成为可能。 随着后来的适应而变化，并测试 随时间的反应是由基因决定的。 这些研究结果 应该可以解释身体成分的一些不明变化， 在体重减轻和体重增加期间观察到代谢。

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.