Patterns of weight change for 31,940 non-smoking women aged 30-55 y in 1976 were examined for 8 y of follow-up. Each woman reported her weight every 2 y on questionnaires, and diet was assessed in 1980 with a semiquantitative food frequency questionnaire. Self-reported weight was highly correlated over time, decreasing from r = 0.95 over 2 y to r = 0.89 over 8 y. Weight gain was inversely related to age (r = -0.06). Weight change in a given 2-y interval was inversely related to change in weight over the subsequent 2 y (r = -0.30). Age, relative weight, and prior weight change were stronger predictors of recent weight change than were intake patterns of specific nutrients. Recent prior weight change was the strongest predictor of subsequent weight change. In a population of free-living women, prior weight loss and younger age are far stronger predictors of subsequent weight gain than are the qualitative aspects of diet.