Sleep, mental health, and body weight change in adults with obesity

Sleep quality and affective disorders have independent associations with weight change, but how mental health and sleep interact to impact weight loss is unknown. The purpose of this study was to examine associations between baseline affective disorders, changes in sleep quality, and their impact on weight loss over 24 months among adults in a weight loss trial.

A secondary (cohort) analysis was conducted using data from the RE-POWER trial. Participants (n = 1298) were categorized by their affective disorder status at baseline and their 6-month changes in sleep quality (large improvement, moderate improvement, stable, or declined). Weight loss over 24 months was modeled as a continuous variable and as ≥ 5% weight loss threshold.

In the model examining the ≥ 5% weight loss, there was a significant interaction (p = 0.035) between affective disorders, sleep quality change, and time. Among participants with an affective disorder, 54% of those with stable sleep and 60% of those with improved sleep achieved ≥ 5% weight loss, whereas just 31% of participants who experienced sleep decline achieved ≥ 5% weight loss by 6 months. By 24 months, the proportion of participants who lost ≥ 5% of their baseline body weight was more similar across groups. Exposure interactions were not significant in the continuous model of weight loss.

Baseline mental health and sleep quality decline can interact to inhibit successful weight loss, at least in the short term. Future weight management interventions should consider monitoring both affective disorders and sleep quality as potential markers for needing additional intervention support.