Di Pietro L, Dziura J, Blair S N
The John B. Pierce Laboratory, Yale University School of Medicine, New Haven, CT 06519, USA.
Int J Obes Relat Metab Disord. 2004 Dec;28(12):1541-7. doi: 10.1038/sj.ijo.0802821.
To determine the relation between the average daily physical activity level (PAL) and the trajectory of weight change in men at risk for weight gain.
Clinic-based cohort study over an average of 5 y.
Healthy men (N=2501) ages 20-55 y participating in the Aerobics Center Longitudinal Study who had received at least four medical examinations at the Cooper Clinic between 1970 and 1998.
Daily leisure-time physical activity was reported and body weight was measured at all four examinations. The average daily PAL (METs 24 h(-1)) was estimated from all activities, as well as from other incidental active and passive activities. Weight change over four examinations was regressed on the change in PAL between the first and third examinations.
Random coefficient regression modeling indicated a curvilinear slope for weight gain over the follow-up among those maintaining the same PAL between the first and third examinations. Weight gain was further accelerated among men who decreased their activity. A shift from a low PAL (<1.45 METs 24 h(-1)) to a moderate (1.45-1.60 METs 24 h(-1)) or high (>1.60 METs 24 h(-1)) PAL was necessary for weight loss over time. Men with initially the lowest PAL had the greatest benefit from increasing activity.
Daily PAL was inversely related to weight gain in this cohort. Increasing to or maintaining a daily PAL at least 60% above the resting metabolic rate (ie, PAL >1.60 METs 24 h(-1)) may be necessary to maintain body weight in middle-age and can be achieved by incorporating 45-60 min of brisk walking, gardening/yardwork, or cycling into the daily routine.
确定平均每日身体活动水平（PAL）与体重增加风险男性体重变化轨迹之间的关系。
基于诊所的队列研究，平均随访5年。
年龄在20 - 55岁之间的健康男性（N = 2501），参与有氧运动中心纵向研究，于1970年至1998年期间在库珀诊所接受了至少四次医学检查。
在所有四次检查中均报告每日休闲时间身体活动情况并测量体重。根据所有活动以及其他偶然的主动和被动活动估算平均每日PAL（代谢当量·24小时⁻¹）。将四次检查期间的体重变化与第一次和第三次检查之间PAL的变化进行回归分析。
随机系数回归模型表明，在第一次和第三次检查之间保持相同PAL的人群中，随访期间体重增加呈曲线斜率。活动减少的男性体重增加进一步加速。随着时间推移，体重减轻需要从低PAL（<1.45代谢当量·24小时⁻¹）转变为中等（1.45 - 1.60代谢当量·24小时⁻¹）或高（>1.60代谢当量·24小时⁻¹）PAL。最初PAL最低的男性从增加活动中获益最大。
在该队列中，每日PAL与体重增加呈负相关。为在中年维持体重，可能需要将每日PAL提高到或维持在比静息代谢率至少高60%的水平（即，PAL >1.60代谢当量·24小时⁻¹），这可通过将45 - 60分钟的快走、园艺/庭院工作或骑自行车纳入日常活动来实现。
