A randomized trial of interactive group sessions achieved greater improvements in nutrition and physical activity at a tiny increase in cost

Weight gain may follow altered eating habits and decreased physical activity in couples beginning to live together. Mutual support and willingness to accept changes in lifestyle at this stage may facilitate positive responses to health promotion. We aimed to compare the effects of a diet and physical activity program in couples using a randomized controlled trial.Study design and settingCouples were randomized to a control group or to one of two intervention groups in whom the program was either delivered mainly by mail or with a combination of mail-outs and interactive group sessions.ResultsDiets, physical fitness, and blood cholesterol improved up to 12 months after beginning the 4-month program, mainly in the interactive group. In that group, at the end of the program, the estimated cost was $445.30 ($111.33/month) per participant per unit change in outcome variables, only $0.03 per participant per month more than the group receiving the program mainly by mail. One year after beginning the program, costs per participant per month were $38.37 in the interactive group and $38.22 in the group receiving the program mainly by mail-out.ConclusionThe changes observed in cardiovascular risk factors could translate to a substantial cost-savings relating to health.