A representative sample of university freshman women were compared to same-aged community women for rate of weight change. University women were found to gain a mean of .73 lbs/month, 36 times faster than community women. Analysis of variance showed that university women gained significantly more excess weight than did community women. The incidence of developing "treatable" excess weight was 26% and 9% for university and community women, respectively. University women were 2.6 to 5.2 times as likely as community women to gain 15% or more above ideal weight. Three-year follow-up of university women showed a stabilization and reduction in mean weight for sophomore and junior years. By the junior year, average weight returned to near baseline levels as entering freshman. Mean excess weight loss was associated with a move from mandatory dormitory housing and cafeteria food services. Young adult university women (and men) may be especially important nonclinical study populations for identifying behavioral factors involved in weight gain and self-correcting weight loss, which could be valuable for development of more effective obesity prevention programs.