OBJECTIVE Understanding how changes in weight over the life course shape risk for diabetes is critical for the prevention of diabetes. Using data from the National Health and Nutrition Examination Survey (NHANES), we investigated the association between self-reported weight change from young adulthood to midlife and incident diabetes.

RESEARCH DESIGN AND METHODS We categorized individuals into four weight-change groups: those who remained nonobese (stable nonobese), those who moved from an obese BMI to a nonobese BMI (losing), those who moved from a nonobese BMI to an obese BMI (gaining), and those who remained obese (stable obese). Diabetes status was determined by self-report of a prior diagnosis, and age at diagnosis was used to establish time of diabetes onset. Hazard ratios (HRs) relating weight change to incident diabetes over 10 years of follow-up were calculated using Cox models adjusting for covariates.

RESULTS Those who were obese and lost weight exhibited a significantly lower risk (HR 0.33; 95% CI 0.14, 0.76) of diabetes compared with those with stable obesity. We also observed lower risk among those who were stable nonobese (HR 0.22; 95% CI 0.18, 0.28) and those in the gaining category (HR 0.70; 95% CI 0.57, 0.87). Further, there was evidence of an increased incidence of diabetes among obese individuals who lost weight compared with individuals who were stable nonobese; however, weight loss was rare, and the association was not statistically significant. If those who were obese had become nonobese during the 10-year period, we estimate that 9.1% (95% CI 5.3, 12.8) of observed diabetes cases could have been averted, and if the population had maintained a normal BMI during the period, 64.2% (95% CI 59.4, 68.3) of cases could have been averted.

CONCLUSIONS The findings from this study underscore the importance of population-level approaches to the prevention and treatment of obesity across the life course of individuals.

目的了解体重在整个生命过程中的变化如何影响糖尿病风险对于预防糖尿病至关重要。使用来自美国国家健康和营养检查调查（NHANES）的数据，我们调查了自我报告的从成年后到中年的体重变化与糖尿病的相关性。

研究设计和方法我们将个体分为四个体重变化组：那些保持非肥胖（稳定的非肥胖），从肥胖BMI转变为非肥胖BMI（失去）的人，从非肥胖BMI转变为肥胖BMI的人（增加），以及那些仍保持肥胖状态（稳定肥胖）的人。糖尿病状态由先前诊断的自我报告确定，诊断时的年龄用于确定糖尿病发作的时间。使用针对协变量进行调整的Cox模型，计算了在10年的随访中与体重变化和糖尿病相关的危险比（HRs）。

结果与稳定肥胖者相比，肥胖和减肥者的糖尿病风险显着降低（HR 0.33； 95％CI 0.14，0.76）。我们还观察到稳定的非肥胖者（HR 0.22； 95％CI 0.18，0.28）和获益人群中的风险较低（HR 0.70； 95％CI 0.57，0.87）。此外，有证据表明，与稳定的非肥胖者相比，体重减轻的肥胖个体中糖尿病的发病率增加。然而，体重减轻很少见，且相关性在统计学上不显着。如果肥胖者在10年内变得不肥胖，我们估计可以避免所观察到的糖尿病病例的9.1％（95％CI 5.3，12.8），并且在此期间该人群的BMI保持正常，可以避免64.2％（95％CI 59.4，68.3）的案件。

结论这项研究的结果强调了在整个生命过程中采用人群水平的方法来预防和治疗肥胖的重要性。