Objectives. This study examined whether weight gain with age could be prevented through the use of a low-intensity intervention. Methods. Participants, 228 men and 998 women recruited from diverse sources, were randomized to one of the following groups: (1) no-contact control, (2) education through monthly newsletters, or (3) education plus incentives for participation. All participants were weighed and completed questionnaires about behaviors and attitudes related to weight at baseline and annually for 3 years thereafter. Results. Individuals in intervention groups reported favorable changes over time in frequency of weighing and healthy dieting practices relative to those in the control group. These behavior changes were in turn related to a reduced rate of weight gain over time. However, weight gain over 3 years did not differ significantly by treatment group. Conclusions. This low-intensity educational approach to weight gain prevention sustained interest over a lengthy time period and was associated positively with behavior change, but it was not strong enough to significantly reduce weight gain with age.