This study evaluated the feasibility and effectiveness of a program for weight gain prevention in normal-weight adults. Two hundred nineteen participants were randomized to either weight gain prevention treatment or no treatment for a period of 12 months. Those in the treatment group received monthly newsletters relating to weight management, participated in a financial incentive system, and were offered an optional four-session education course in the sixth month of the program. Results demonstrated high interest in weight gain prevention among individuals who were not objectively overweight. Participation, as measured by return of postcards sent with each newsletter, was approximately 75%. Results after 1 year showed a net weight loss in the group receiving the program of 1.8 lb compared to those in the control group. Eighty-two percent of program participants maintained or lost weight, compared to 56% of the control group. It is concluded that programs for weight gain prevention are feasible in adults and may be more effective than weight loss treatment programs in addressing the problem of community-wide obesity.