Benefits of adding small financial incentives or optional group meetings to a web-based statewide obesity initiative

To examine whether adding either small, variable financial incentives or optional group sessions improves weight losses in a community-based, Internet behavioral program.

Participants (N = 268) from Shape Up Rhode Island 2012, a 3-month Web-based community wellness initiative, were randomized to: Shape Up+Internet behavioral program (SI), Shape Up+Internet program+incentives (SII), or Shape Up+Internet program+group sessions (SIG).

At the end of the 3-month program, SII achieved significantly greater weight losses than SI (SII: 6.4% [5.1-7.7]; SI: 4.2% [3.0-5.6]; P = 0.03); weight losses in SIG were not significantly different from the other two conditions (SIG: 5.8% [4.5-7.1], P's ≥ 0.10). However, at the 12-month no-treatment follow-up visit, both SII and SIG had greater weight losses than SI (SII: 3.1% [1.8-4.4]; SIG: 4.5% [3.2-5.8]; SI: 1.2% [-0.1-2.6]; P's ≤ 0.05). SII was the most cost-effective approach at both 3 (SII: $34/kg; SI: $34/kg; SIG: $87/kg) and 12 months (SII: $64/kg; SI: $140/kg; SIG: $113/kg).

Modest financial incentives enhance weight losses during a community campaign, and both incentives and optional group meetings improved overall weight loss outcomes during the follow-up period. However, the use of the financial incentives is the most cost-effective approach.