Coach access to digital self‐monitoring data: an experimental test of short‐term effects in behavioral weight‐loss treatment

Objective This study experimentally tested whether coach access to participants' digital self‐monitoring data improved behavioral weight‐loss outcomes. Methods Participants ( N = 322) received 12 weeks of group‐based behavioral weight‐loss sessions via videoconference and were instructed to engage in daily self‐monitoring of weight, physical activity (PA), and dietary intake. For participants who were randomly assigned to Coach Share ON ( n = 161), coaches regularly accessed a web‐based portal that displayed data from the participants' scale, PA sensor, and food record. Results Weight loss at 12 weeks was significantly greater in Coach Share ON versus OFF (6.2% vs. 5.3%; p = 0.04). Self‐monitoring of PA (98.70% vs. 97.40% of days; p = 0.006) and eating (98.05% vs. 93.51% of days; p = 0.007) was more frequent in Coach Share ON versus OFF. There were no significant differences by condition in PA ( p = 0.57), attendance ( p = 0.42), working alliance ( p = 0.62), or self‐monitoring of weight ( p = 0.12). Perceived supportive accountability was significantly greater in Coach Share ON versus OFF ( p < 0.001). Conclusions The short‐term efficacy of behavioral weight loss was greater when coaches had direct access to self‐monitoring device data. Notably, there also was no evidence of iatrogenic effects of data sharing.