Background: The question of whether weight loss increases a person's longevity is important given the high prevalence of obesity and the large number of people trying to lose weight in industrialized countries.
Objective: This study assessed the effect of body mass index (BMI) and weight change (within 1 y of baseline) on subsequent mortality.
Design: This prospective cohort study had a median follow-up of 17 y. Subjects were 8100 women aged 50-66 y who participated in a population-based breast cancer-screening project in the Netherlands between 1974 and 1977. Weight and height were measured during the first and second screening visits. All women were followed until 1996 for causes of death. Cox proportional hazard analyses were conducted for mortality from all causes (n = 1269), cardiovascular disease (CVD; n = 402), and cancer (n = 492).
Results: During follow-up we observed a statistically significant increased risk of mortality from all causes (hazard ratio: 1.4; 95% CI: 1.2, 1.6), cardiovascular disease, and cancer for women in the highest quartile of BMI (in kg/m(2)), > or =27.77. Mortality from all causes, CVD, and cancer did not increase significantly in women with a weight gain of > or =15%. Weight loss was also not significantly related to mortality from all causes, CVD, and cancer.
Conclusions: Mortality was highest for women in the highest BMI quartile (> or =27.77). Extreme weight gain or weight loss within 1 y was not statistically significantly associated with subsequent higher mortality.