Can targeted recruitment methods affect male participation in weight loss interventions and trials?

Behavioral weight loss studies often enroll more females than males despite similar obesity prevalence. There is a paucity of experimental evidence on recruitment strategies to attract male participants in behavioral trials broadly and in weight management trials, specifically.

We examined 4 theory and evidence-based advertising messages and 4 recruitment modalities (mailing, emailing, Facebook, and Spotify) in three iterative waves during a decentralized longitudinal randomized controlled trial comparing 2 behavioral weight loss interventions.

The number of ad clicks and web screens completed did not appear to differ among the messages. Facebook was the most cost-effective overall ($32.86 per recruited person) with the highest proportion of male interest when the message was tailored and campaigns were set to target males (79%), but mailing produced the higher total rate of potential participants screened and garnered a higher proportion of male interest overall (23% average across all waves), albeit it at greater cost.

Social media is a cost-efficient recruitment avenue, although it may reduce the ability to assemble a representative sample. Future studies should formally experiment with recruitment to inform robust recommendations.