Lifestyle intervention is the first line treatment for paediatric obesity, yet the weight loss effects are variable. This study aimed to examine the association between early weight loss and outcomes at 24 months in obese adolescents with clinical features of insulin resistance participating in a 12-month lifestyle intervention with metformin.
Adolescents (n=111, 66 girls, age: 10 to 17 years) were participants in a randomized trial, the RESIST study, which examined the effects of two diets differing in macronutrient content on insulin sensitivity.1 Eighty-five completed the 12-month program and follow-up data at 24 months were available for 42 adolescents. Change in weight was determined by BMI expressed as percentage of the 95th centile (BMI95).2
After 3 months intervention, 90 adolescents lost weight (median BMI95 change -7, IQR: -9.7, -3.7), of which 45 adolescents lost ≥5% weight (BMI95) and 7 adolescents lost ≥10%. More than half of the adolescents who lost ≥5% BMI95 at 3 months, increased or maintained their weight loss at 12 months (62%) and 24 months (52%), respectively. In contrast, adolescents who did not lose weight at 3 months were more likely to have dropped out at 12 months (odds ratio 2.8[95%CI: 1.3 to 5.9], P=0.016) or were less likely to have lost weight during the 12 month intervention (OR 3.2 [95%CI 1.5 to 7.0], P=0.018), or at the 24 month follow-up (OR 2.8 [95%CI 1.8 to 4.3, P=0.005]. There was no statistical significant difference in weight outcomes between diets at any time point, nor did sex, baseline age, baseline BMI95 or index of insulin resistance predict weight loss at 12 and 24 months.
Early weight loss in obese adolescents may be used as an indicator to identify treatment nonresponders and intervention strategies could be modified to improve outcomes.