Introduction
Lifestyle interventions in adolescents with obesity can result in weight loss in the short to medium-term but individual responses vary widely. This study aimed to identify predictors of weight loss at 12- and 24-months in adolescents with obesity and clinical features of insulin resistance.
Methods
Adolescents (n=111, 66 girls, aged 10-17 years) were participants in a randomised controlled trial (RCT), the RESIST study, examining the effects of two diets differing in macronutrient content on insulin sensitivity. Eighty-five completed the 12-month lifestyle intervention and 24-month follow-up data were available for 42 adolescents. Change in weight was determined by BMI expressed as percentage of the 95th centile (BMI95).The study physician collected socioeconomic data at baseline. Physical activity, screen time and psychological dimensions of eating behaviour were self-reported using the validated CLASS and EPI-C questionnaires. Stepwise multiple regressions were conducted to identify models that best predicted change in BMI95 at 12- and 24-months.
Results
Mean BMI95 was reduced at 12-months compared with baseline (mean difference [MD] ± SE: -6.9±1.0, P<0.001) but adolescents had significant re-gain from 12- to 24-months (MD ± SE: 3.7±1.5, P=0.017). Participants who achieved greater 12-month weight loss had: greater 3-month weight loss, a father with a higher education, lower baseline external eating and parental pressure to eat scores and two parents living at home. Participants who achieved greater 24-month weight loss had: greater 12-month weight loss and a lower baseline emotional eating score.
Conclusion
Early weight loss is consistently identified as a strong predictor of long-term weight loss. This could be because early weight loss identifies those more motivated and engaged individuals. Patients who do not achieve early weight loss might benefit from additional support or transition to an alternate intervention where they may have increased success.