Hartmut Lode, Jutta Wagner, Hans Scherübl

Purpose We evaluated trends in the incidence of overweight and obesity over the past 50 years. Methods We evaluated trends in the incidence of overweight (25 ≤ body mass index [BMI] <30 kg/m2), obesity (BMI ≥30 kg/m2) and stage 2 obesity (BMI ≥35 kg/m2) from 1950 to 2000 in Framingham Study participants (n = 6798, 54% women). Individuals aged 40-55 years who attended 2 examinations 8 years apart in each decade were eligible. Results The incidences of overweight, obesity, and stage 2 obesity increased across the decades in both sexes (P for trend <.001). For men, the incidence of overweight rose from 21.8% (95% confidence interval [CI], 17.6-26.5) in the 1950s to 35.2% (95% CI, 28.6-42.5) in the 1990s; of obesity from 5.8% (95% CI, 4.4-7.6) to 14.8% (95% CI, 12.2-17.9); and of stage 2 obesity from 0.2% (95% CI, 0.1-0.9) to 5.4% (95% CI, 4.0-7.2). For women, incidence rates of overweight increased from 15.0% (95% CI, 12.3-18.1) to 33.1% (95% CI, 29.0-37.4); of obesity from 3.9% (95% CI, 2.9-5.3) to 14% (95% CI, 11.6-16.7); and of stage 2 obesity from 1.7% (95% CI, 1.1-2.6) to 4.4% (95% CI, 3.2-6.0). Overall, incidence rates of overweight increased 2-fold and that of obesity more than 3-fold over 5 decades, findings that remained robust upon additional adjustment for baseline BMI in each decade. Conclusions The incidence of overweight and obesity increased progressively over the last 5 decades, suggesting that the rising trend in prevalence is not a recent phenomenon.