ELECTRONICALLY RECORDED SELF-WEIGHING IN BEHAVIORAL TREATMENT FOR WEIGHT LOSS

Background: Self-weighing is a recommended but understudied weight loss strategy. \ud Objectives: 1) Examine the mediating effects of adherence to energy intake (EI) and energy expenditure (EE) goals on the association between self-weighing and weight changes; 2) Identify self-weighing patterns and examine differences in adherence to EI/EE goals and weight changes across self-weighing patterns; 3) Explore participants’ experience of daily self-weighing.\ud Methods: The study included two methodological approaches. In the quantitative component, we conducted a secondary analysis of self-weighing data from a clinical trial (SELF) and a longitudinal, descriptive study of behavioral treatment for weight loss (EMPOWER). Outcome weight was measured every 6 months in the project office. Adherence to self-weighing protocols was calculated using data from electronic scales in the participants’ homes. Adherence to EI/EE goals was obtained from the self-monitoring data. Linear mixed modeling, mediation analysis and group-based trajectory modeling were used for analysis. In the qualitative component, we conducted three focus groups to explore participants’ experience of daily weighing. Content analysis was used to identify themes.\ud Results: During the first six months of the SELF study, there was a significant mediation effect of adherence to EI and EE goals on the association between adherence to self-weighing and percent weight change (indirect effect: b=-0.26, p=0.02; b=-0.23, p=0.02). Using EMPOWER study data, three patterns of self-weighing were identified: high/consistent (75.0% self-weighed ≥6 days/week regularly); moderate/declined (16.2% declined from 4-5 to 2 days/week); minimal/declined (8.8% declined from 5-6 to 0 days/week). The high/consistent group achieved greater weight loss than the other two groups at 6 months (10.19%, 5.45%, and 2.00%) and 12 months (9.90%, 5.62%, and 0.65%). Focus group data revealed reasons for daily self-weighing included feeling motivated, providing feedback for eating and exercise behaviors, and feeling in control. Reasons for not weighing daily included interruption of routine and weight gain. The main suggestion for future users of this strategy was learning to accept a normal range of weight fluctuation.\ud Conclusions: Findings suggest that the majority of participants were able to sustain a habit of daily self-weighing, which impacts weight changes directly and indirectly through changes in EI and EE