Nelson Melissa C, Gordon-Larsen Penny, North Kari E, Adair Linda S
Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, USA.
Obesity (Silver Spring). 2006 Apr;14(4):701-9. doi: 10.1038/oby.2006.80.
The magnitude of environmental vs. genetic effects on BMI, diet, and physical activity (PA) is widely debated. We followed a sibling cohort (where individuals shared households in childhood and adolescence) to young adulthood (when some continued sharing households and others lived apart) to examine the role of discordant environments in adult twins' divergent trends in BMI and health behaviors and to quantify the variation in BMI and behavior among all siblings that is attributable to environmental and additive genetic effects.
In the National Longitudinal Study of Adolescent Health, siblings sharing households for > or =10 years as adolescents (mean age = 16.5 +/- 1.7 years; N = 5524) were followed into adulthood (mean = 22.4 +/- 1.8 years; N = 4368), self-reporting PA, sedentary behavior, and dietary characteristics. Adult BMI and adolescent z scores were derived from measured height and weight.
Compared with those living together, twins living apart exhibited greater discordance in change in BMI, PA, and fast food intake from adolescence to adulthood. Adolescent household environments accounted for 8% to 10% of variation in adolescent fast food intake and sedentary behaviors and 50% of variation in adolescent overweight. Adolescent household effects on PA were substantially greater in young adulthood (accounting for 50% of variation) vs. adolescence. Young adult fast food intake was significantly affected by young adult household environment, accounting for 12% of variation.
These findings highlight important environmental influences on BMI, PA, and fast food intake during the transition to adulthood. Household and physical environments play an important role in establishing long-term behavior patterns.
环境因素与遗传因素对体重指数（BMI）、饮食及身体活动（PA）影响的程度存在广泛争议。我们追踪了一个同胞队列（个体在儿童期和青少年期同住一个家庭）直至青年期（此时一些人继续同住，另一些人分开居住），以研究不一致的环境在成年双胞胎BMI及健康行为差异趋势中的作用，并量化所有同胞中BMI和行为的变异，这些变异可归因于环境和加性遗传效应。
在全国青少年健康纵向研究中，追踪了青少年时期同住家庭≥10年（平均年龄=16.5±1.7岁；N=5524）的同胞至成年期（平均年龄=22.4±1.8岁；N=4368），他们自我报告身体活动、久坐行为及饮食特征。成人BMI和青少年z分数由测量的身高和体重得出。
与同住的双胞胎相比，分开居住的双胞胎在从青少年到成年期的BMI、身体活动及快餐摄入量变化方面表现出更大的不一致。青少年家庭环境占青少年快餐摄入量和久坐行为变异的8%至10%，占青少年超重变异的50%。青少年家庭对身体活动的影响在青年期（占变异的50%）比在青少年期大得多。青年期快餐摄入量受青年期家庭环境的显著影响，占变异的12%。
这些发现突出了在向成年期过渡期间环境对BMI、身体活动和快餐摄入量的重要影响。家庭和物理环境在建立长期行为模式中起重要作用。
