Effects of Intervention Characteristics on Willingness to Initiate a Weight Gain Prevention Program

To determine characteristics of weight gain prevention programs that facilitate engagement.

Randomized factorial experiment (5 × 2).

Recruited nationally online.

Adults aged 18 to 75 with body mass index ≥25 who decline a behavioral weight loss intervention (n = 498).

Participants were randomly presented with one of 10 possible descriptions of hypothetical, free weight gain prevention programs that were all low dose and technology-based but differed in regard to 5 behavior change targets (self-weighing only; diet only; physical activity only; combined diet, physical activity, and self-weighing; or choice between diet, physical activity, and self-weighing targets) crossed with 2 financial incentive conditions (presence or absence of incentives for self-monitoring). Participants reported willingness to join the programs, perceived program effectiveness, and reasons for declining enrollment.

Logistic regression and linear regression to test effects of program characteristics offered on willingness to initiate programs and programs' perceived effectiveness, respectively. Content analyses for open-ended text responses.

Participants offered the self-weighing-only programs were more willing to initiate than those offered the programs targeting all 3 behaviors combined (50% vs 36%; odds ratio [OR] = 1.79; 95% confidence interval [CI], 1.01-3.13). Participants offered the programs with financial incentives were more willing to initiate (50% vs 33%; OR = 2.08; 95% CI, 1.44-2.99) and anticipated greater intervention effectiveness (β = .34, P = .02) than those offered no financial incentives. Reasons for declining to initiate included specific program features, behavior targets, social aspects, and benefits.

Targeting self-weighing and providing financial incentives for self-monitoring may result in greater uptake of weight gain prevention programs.

https://osf.io/b9zfh, June 19, 2018.