Parsons Tessa J, Manor Orly, Power Chris
Department of Paediatric Epidemiology and Biostatistics, Institute of Child Health, 30 Guilford Street, London, UK.
Int J Epidemiol. 2006 Feb;35(1):197-204. doi: 10.1093/ije/dyi291. Epub 2005 Dec 22.
Prevention of obesity has focused on childhood as a target period. Our aim was to assess whether frequency of adolescent physical activity affected subsequent body mass index (BMI) gain through to mid-adulthood.
The British birth cohort of all births in 1 week in March 1958, includes information on physical activity frequency and BMI for several ages, 11-45 years. We examined relationships between activity in adolescence and trajectories of BMI between 16 years (or 23 years) and 45 years using multi-level models. Effects of change in activity on BMI and on change in BMI were tested using ANOVA.
Physical activity at 11 years had no effect on the BMI trajectories, in males or females. More active females at 16 years gained BMI more slowly than others, by 0.007 kg/m2/year per activity category over the period 16-45 years, whereas the most active males gained BMI faster than others, by 0.005 kg/m2/year per activity category. This effect in males was not evident on the BMI trajectory from 23 to 45 years. Consistent with these analyses, change in activity was associated with change in BMI in females, e.g. females active at 16 and 42 years gained less BMI than inactive females (2.1 vs 2.5 kg/m2/10 years). Results for males were inconsistent over the time periods examined.
Physical activity may lessen the gains in BMI from adolescence onwards, but relationships vary with age, and in later adolescence show opposite effects for males and females. Decreasing activity between adolescence and mid-adulthood in males, and inactivity in both life stages in females may increase BMI gain.
肥胖预防一直将儿童期作为目标阶段。我们的目的是评估青少年身体活动频率是否会影响直至中年期的后续体重指数（BMI）增长。
1958年3月某一周内所有出生的英国出生队列，包含了11至45岁几个年龄段的身体活动频率和BMI信息。我们使用多层次模型研究了青少年时期的活动与16岁（或23岁）至45岁期间BMI轨迹之间的关系。使用方差分析测试了活动变化对BMI以及BMI变化的影响。
11岁时的身体活动对男性或女性的BMI轨迹均无影响。16岁时活动较多的女性BMI增长比其他人慢，在16至45岁期间，每增加一个活动类别，BMI每年增长减慢0.007kg/m²，而活动最频繁的男性BMI增长比其他人快，每增加一个活动类别，BMI每年增长加快0.005kg/m²。这种男性的效应在23至45岁的BMI轨迹上并不明显。与这些分析一致，活动变化与女性的BMI变化相关，例如，16岁和42岁时活跃的女性比不活跃的女性BMI增加更少（2.1 vs 2.5kg/m²/10年）。在所研究的时间段内，男性的结果不一致。
身体活动可能会减少从青春期开始的BMI增长，但这种关系因年龄而异，并且在青春期后期对男性和女性表现出相反的影响。男性在青春期至中年期活动减少，以及女性在两个生命阶段都不活动，可能会增加BMI增长。
