title: Exercise mitigates cumulative associations between stress and BMI in girls age 10 to 19.
abstract: OBJECTIVE
  Long-term psychological stress is associated with BMI increases in children as they transition to adulthood, whereas long-term maintenance of physical activity can slow excess weight gain. We hypothesized that in addition to these main effects, long-term physical activity mitigates the relationship between long-term stress and BMI increase.
  
  
  METHODS
  The NHLBI Growth and Health Study enrolled 2,379 10-year-old Black and White girls, following them annually for 10 measurement points. Growth curve modeling captured the dynamics of BMI, measured yearly, and stress and physical activity, measured at varying years.
  
  
  RESULTS
  At average levels of activity and stress, with all covariates remaining fixed, average BMI at baseline was 19.74 (SE = 0.38) and increased 0.64 BMI (SE = 0.01, p < .001) units every year. However, this increase in BMI significantly varied as a function of cumulative stress and physical activity. Slower BMI gain occurred in those girls who were less stressed and more active (0.62 BMI units/year, SE = .02, p < .001), whereas the most rapid and largest growth occurred in girls who were more stressed and less active (0.92 BMI units/year, SE = .02, p < .001). Racial identification did not alter these effects.
  
  
  CONCLUSIONS
  As hypothesized, in girls who maintained long-term activity, BMI growth was mitigated, even when reporting high long-term stress, compared with less physically active girls. This study adds to a converging literature in which physical activity, a modifiable prevention target, functions to potentially limit the damaging health effects of long-term psychological stress.
authors: Department of Psychiatry, University of California San Francisco.
authors: Eli
authors: E
authors: Puterman
authors: Department of Psychiatry, University of California San Francisco.
authors: Aric A
authors: AA
authors: Prather
authors: Department of Psychiatry, University of California San Francisco.
authors: Elissa S
authors: ES
authors: Epel
authors: Chicago College of Osteopathic Medicine.
authors: Sheila
authors: S
authors: Loharuka
authors: Department of Psychiatry, University of California San Francisco.
authors: Nancy E
authors: NE
authors: Adler
authors: School of Public Health, University of California Berkeley.
authors: Barbara
authors: B
authors: Laraia
authors: Department of Psychiatry, University of California San Francisco.
authors: A Janet
authors: AJ
authors: Tomiyama
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D002648:Child; D015444:Exercise; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D063766:Pediatric Obesity / Q000453:epidemiology / Q000517:prevention & control*; D013315:Stress, Psychological / Q000453:epidemiology*; D055815:Young Adult