Changes in leukocyte telomere length among children with obesity participating in a behavioural weight control program

Summary Objective To examine changes in leukocyte telomere length (LTL) during and after a behavioural weight control program for children with obesity. Methods We measured LTL among a cohort of 158 children 8–12 years of age with a body mass index greater than or equal to the 95th percentile for age and sex. Children were 55% female, 29% white, 52% Latinx, 8% Asian and 11% Pacific Islander, other or multiethnic. All children participated in a 6‐month, family‐based, group behavioural weight control program and were assessed before treatment, after treatment and 1 year after the end of treatment. To test the sample population slope of LTL over the intervention and maintenance time periods, we fit spline mixed‐effect regression models. Results LTL increased an average of 0.09 T/S units per year (95% confidence interval [CI] 0.04 to 0.13; p = 0.0001) during the weight control program intervention period, followed by an average decline of −0.05 T/S units per year (95% CI −0.08 to −0.03; p < 0.0001) during the 1 year of follow‐up after the completion of the intervention. Among 26 social, psychological, behavioural and physiological factors we examined, we did not find any predictors of these changes. Conclusions LTL increased in response to a behavioural weight control program among children with obesity, suggesting an impact on biological health and cellular aging from participation in a behavioural weight control intervention. LTL may be a useful biomarker for assessing changes in response to behavioural interventions.