Weight loss and changes in generic and weight-specific quality of life in obese adolescents

To investigate how weight loss correlates with changes in generic and weight-specific quality of life (QoL).

Youth generic (YQOL-S) and weight-specific instruments (YQOL-W) from 133 youth age 11-19 were analyzed at the beginning and end of 4-week immersion camp sessions known to produce weight loss. Paired samples t tests were used to test mean difference between baseline and final Body Mass Index (BMI) and YQOL-S and YQOL-W scores. YQOL-S and YQOL-W scores were transformed to values between 0 and 100, with higher values indicating better QOL. Cohen's d effect sizes were calculated to assess magnitude of effects. Percent weight loss (as % of baseline weight), change in BMI (baseline kg/m²-follow-up kg/m²), and change in % overweight ((BMI-50th% BMI for age and sex)/50th% BMI for age and sex × 100) were calculated. Multiple regressions were used to model final YQOL scores in the 11-14 and 15-19 age groups as functions of each measure of weight change, sex, age, and baseline YQOL score.

Youth experienced significant reductions in BMI (Mean change = 3.7, SD = 1.4, t = 34.1, P < 0.001) and in the other measures of weight change. YQOL-S and YQOL-W scores improved significantly (P < 0.001), and effect sizes were 0.61 and 0.66, respectively.

Changes in generic and weight-specific quality of life scores are associated with weight loss. The weight-specific measure is slightly more sensitive to weight changes; however, when controlling for modifiers, the YQOL-W remained significantly associated with weight loss, while the generic QoL measure did not.