Relation between dieting and weight change among preadolescents and adolescents.
OBJECTIVE
To assess whether dieting to control weight was associated with weight change among children and adolescents.


METHODS
A prospective study was conducted of 8203 girls and 6769 boys who were 9 to 14 years of age in 1996, were in an ongoing cohort study, and completed at least 2 annual questionnaires between 1996 and 1999. Dieting to control weight, binge eating, and dietary intake were assessed annually from 1996 through 1998 with instruments designed specifically for children and adolescents. The outcome measure was age- and sex-specific z score of body mass index (BMI).


RESULTS
In 1996, 25.0% of the girls and 13.8% of the boys were infrequent dieters and 4.5% of the girls and 2.2% of the boys were frequent dieters. Among the girls, the percentage of dieters increased over the following 2 years. Binge eating was more common among the girls, but in both sexes, it was associated with dieting to control weight (girls: infrequent dieters, odds ratio [OR]: 5.10; frequent dieters, OR: 12.4; boys: infrequent dieters, OR: 3.49; frequent dieters, OR: 7.30). During 3 years of follow-up, dieters gained more weight than nondieters. Among the girls, frequency of dieting was positively associated with increases in age- and sex-specific z scores of BMI (beta = 0.05 and beta = 0.04 for frequent and infrequent dieters vs nondieters). Among the boys, both frequent and infrequent dieters gained 0.07 z scores of BMI more than nondieters. In addition, boys who engaged in binge eating gained significantly more weight than nondieters.


CONCLUSIONS
Although medically supervised weight control may be beneficial for overweight youths, our data suggest that for many adolescents, dieting to control weight is not only ineffective, it may actually promote weight gain.
Field
Alison E
AE
Division of Adolescent/Young Adult Medicine, Department of Medicine, Children's Hospital Boston and Harvard Medical School, Boston, Massachusetts, USA. alison.field@tch.harvard.edu
Austin
S B
SB
Taylor
C B
CB
Malspeis
Susan
S
Rosner
Bernard
B
Rockett
Helaine R
HR
Gillman
Matthew W
MW
Colditz
Graham A
GA
D000293:Adolescent; D015992:Body Mass Index; D002032:Bulimia / Q000178:diet therapy / Q000453:epidemiology; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004038:Diet, Reducing / Q000706:statistics & numerical data; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D009043:Motor Activity; D009765:Obesity / Q000178:diet therapy / Q000453:epidemiology / Q000517:prevention & control; D011446:Prospective Studies; D012737:Sex Factors; D011795:Surveys and Questionnaires; D017211:Treatment Failure; D015430:Weight Gain; D015431:Weight Loss