Background:The specific underlying causes of adult weight gain remain uncertain. Objective: The objective was to determine the association of 3 measures of eating behavior with weight gain and body mass index (BMI in kg/m(2)) in adults. Design: Current dietary restraint, disinhibition, and hunger were assessed with the use of the Eating Inventory in 638 healthy, nonsmoking women aged 55-65 y. In addition, subjects reported their current weight and height, their weight for 6 age intervals, and chances in voluntary dietary energy restriction over the past 10 y. Current weight and height were validated in 10% of subjects. Results: Current disinhibition strongly predicted weight gain and current BMI (partial r = 0.27 and 0.34, respectively, both P < 0.001). Neither restraint nor hunger was a significant independent predictor of either variable, but the positive associations between disinhibition and both weight gain and BMI were attenuated by restraint (P = 0.016 and 0.010, respectively, after adjustment for confounding variables). In the subpopulation of women who reported a stable level of voluntary dietary energy restriction, disinhibition also strongly predicted weight gain and higher BMI, and restraint was negatively associated with weight gain (partial r = -0.17, P = 0.019). Conclusions: Higher disinhibition is strongly associated with greater adult weight gain and higher cur-rent BMI, and dietary restraint may attenuate this association when disinhibition is high. These findings suggest that eating behavior has an important role in the prevention of adult-onset obesity and that further studies are warranted.