Clinical and experimental studies of obesity

描述(由申请人提供)：我们建议继续对肥胖高危儿童进行的最完整的前瞻性纵向生长发育研究之一。这项研究根据母亲的超重或苗条选择了72名现在9至10岁的儿童，达到了最初的目标，驳斥了人们普遍认为低总能量消耗最早就能预测一岁大小和身体成分的观点。自那以后，研究发现，在两岁时，超重母亲的33个孩子与瘦子母亲的37个孩子在任何身体成分方面都没有区别。到4岁时，高危儿童的体重、体重指数(BMI)、皮褶厚度和瘦体重都更大。到6岁时，他们的体脂水平也明显更高(25%比19%)(6.7公斤到4.8公斤)。其中10人的体重指数超过第85个百分位数(优势比15.7)。我们现在建议研究这些受试者到青春期的发育，重点是决定身体大小的行为因素：能量摄入量和体力活动。我们将首先评估家庭脆弱性对生长和发育的强大影响。接下来，我们将测试食物摄入量和体力活动对身体成分的影响，并确定这些行为在多大程度上中介了家庭脆弱性的影响。能量摄入量将通过食物记录、召回、实验室方案和2份问卷进行评估。体力活动将通过活动监视器、电视和计算机使用监视器以及召回进行评估。这些努力将通过显著的样本维护而得到加强，10年的样本保管率为92%(最初的78名受试者中有72名)，在过去5年中没有一名受试者丢失。家长们报告说，他们将继续到资助期结束。这些受试者将有可能评估行为因素随着时间的推移对已被确定为肥胖高危人群的影响，从而阐明关键的基因-环境相互作用。

DESCRIPTION (provided by applicant): We propose to continue one of the most complete prospective longitudinal studies of growth and development yet undertaken of children at high risk of obesity. The study of 72 children now 9 to 10 years of age, selected on the basis on maternal overweight or leanness, achieved its initial goal, disconfirming the widely held belief that a low total energy expenditure predicted body size and composition as early as one year of age. It has since found that, at 2 years of age, 33 children of overweight mothers did not differ from 37 children of lean mothers in any aspect of body composition. By 4 years of age, high risk children had greater weight, body mass index (BMI), skinfold thickness and lean body mass. By 6 years of age they also had significantly greater levels (25% vs. 19%) (6.7 kg to 4.8) of body fat. Ten had exceeded the 85th percentile for BMI (odds ratio 15.7). We now propose to study the development of these subjects into adolescence focusing on behavioral determinants of body size: energy intake and physical activity. We will first evaluate the powerful influence of familial vulnerability on growth and development. Next, we will test the influence of food intake and physical activity on body composition, and determine the extent to which the influence of familial vulnerability is mediated by these behaviors. Energy intake will be assessed by food records, recalls, laboratory protocols and 2 questionnaires. Physical activity will be assessed with activity monitors and with monitors of television and computer use and by recalls. These efforts will be enhanced by the remarkable sample maintenance, 92% at 10 years (72 out of the original 78 subjects) and no subject has been lost during the past 5 years. Parents report that they will continue to the end of the grant period. These subjects will make it possible to assess the effects of behavioral factors over time in a cohort that has been identified as being at high risk for obesity and thereby elucidate critical gene-environmental interactions.