Association between sleep and weight loss in a 12-month digital lifestyle intervention

We studied how sleep quality and chronotype relate to weight loss in a 12-month real-world digital lifestyle intervention, the Healthy Weight Coaching. Patients self-reported weight and waist circumference and completed a set of customized sleep-related online questionnaires at baseline, 3-, 6-, 9-, and 12-months. Primary outcomes were percent changes in weight and waist circumference, calculated from baseline to each follow-up time point. Using generalized linear regression for repeated measures, we explored associations between sleep variables (individual variables and factor analysis-derived clusters) and changes in measures of obesity across the program. Additionally, we investigated how changes in reported sleep are associated with weight loss outcomes. Baseline data included 1883 individuals (82.6% women, median age 52 years, median BMI 39.1 kg/m 2 ). Reporting sleep apnoea was associated with less successful weight loss across the program [weight, B=0.760 (95% CI=0.446–1.073), p<0.001; waist, B=1.275 (95% CI=0.780–1.771), p<0.001]. Eveningness and Tiredness factors were associated with poorer weight [B=0.206 (95% CI=0.027–0.385), p=0.024 and B=0.613 (95% CI=0.371–0.855), p<0.001, respectively] and waist circumference [B=0.434 (95% CI=0.155–0.713), p=0.002 and B=0.720 (95% CI=0.337–1.102), p<0.001, respectively] reduction over the 12-month program. Increase in reported daytime alertness, over the program, was beneficial for weight loss outcomes. Addressing evening chronotype and reasons for reduced daytime alertness may be associated with enhanced weight loss; however this study does not establish causality. Additional research is needed to adapt interventions for those with sleep apnoea. The trial is registered at clinicaltrials.cov (Clinical Trials Identifier NCT04019249). • We studied the role of sleep in weight loss in a digital lifestyle intervention • Short (<7h) and long sleep (>9h) linked to less weight and waist loss, respectively • Sleep apnea was associated with poorer weight loss over the 12-month program • Higher Eveningness and Tiredness factor scores associated with reduced weight loss • Increase in reported daytime alertness associated with better weight loss outcomes