Objective: To describe the design, methods, and first year results of the Pound of Prevention (POP) study, a randomized trial examining whether weight gain with age can be prevented using low intensity intervention.
Design: Participants were randomized to either (1) no-contact control, (2) education through monthly newsletters and semiannual classes on nutrition and exercise, and (3) education plus a lottery incentive for participation.
Subjects: Two hundred and twenty-eight men, 594 high-income women, and 404 low-income women. Entry requirements were age 20-45 y, healthy, and willing to participate for three years.
Measurements: At baseline and one year later, participants were weighed and completed questionnaires about behaviors and attitudes related to weight and weight control.
Results: Mean body mass indices at baseline were 28.1, 26.1, and 28.2 for men, high-income women and low-income women, respectively. After one year, participants in the intervention conditions reported significantly increased frequency of weight monitoring, but no change in other targeted behaviors. One year weight changes in the control, education, and education plus lottery groups were 1.94 lb, 0.72 lb, and 0.21 lb in men; 1.38 lb, 1.03 lb, and 0.51 lb in high-income women; and 1.30 lb, 2.11 lb, and 3.23 lb in low-income women.
Conclusions: These one-year results suggest that the intervention may be having a greater impact on high than low-income participants.