Longitudinal Associations Between Anhedonia and Body Mass Index Trajectory Groups Among Adolescents.

PURPOSE: Although evidence suggests that anhedonia-a reduced ability to experience pleasure in response to rewarding stimuli-may predict weight gain during adolescence, it remains unclear whether changes in anhedonia during adolescence are associated with changes in body mass index (BMI). This study examines longitudinal associations between changes in anhedonia and developmental trajectories of BMI during adolescence.

METHODS: Self-report measures of anhedonia and BMI were collected at five semiannual assessments among students from 10 high schools in Los Angeles, CA, area (N = 3,396) followed up from the 9th grade to the 11th grade. Four BMI trajectories were identified using growth mixture modeling: (1) stable normative weight; (2) overweight to normative weight (i.e., decreasing BMI); (3) overweight to chronically obese (increasing BMI); and (4) normative weight to overweight (increasing BMI). Latent growth curve modeling estimated baseline level and changes in anhedonia. A multinomial logistic regression model tested associations of baseline level and slope of anhedonia with the four BMI trajectory groups.

RESULTS: Compared with the stable normative BMI trajectory group, each 1-unit standard deviation increase in anhedonia slope increased the odds of membership in the overweight to chronically obese group (odds ratio [OR] [95% confidence interval {CI}] = 1.29 [1.09-1.49], p < .001) and in the normative weight to overweight group (OR [95% CI] = 1.28 [1.04-1.53], p = .006), and decreased the odds of membership in the overweight to normative weight group (OR [95% CI] = .78 [.57-.95], p = .01).

CONCLUSIONS: Across a 2-year period of high school, the rate of change in anhedonia is associated with certain BMI trajectories linked with poorer metabolic health. Increasing anhedonia may be an important risk factor to consider in adolescent obesity prevention.