Changes in obesity between fifth and tenth grades: a longitudinal study in three metropolitan areas.
BACKGROUND
Despite epidemic childhood obesity levels, we know little about how BMI changes from preadolescence to adolescence and what factors influence changes.


METHODS
We studied 3961 randomly selected public school students and 1 parent per student in 3 US metropolitan areas in fifth and again in tenth grades. In each grade, we measured child and parent height/weight and calculated BMI category. We examined whether baseline sociodemographic characteristics, child health-related factors, and parental obesity were significantly associated with exit from and entry into obesity from fifth to tenth grade.


RESULTS
Fifth- and tenth-graders were 1%/2% underweight, 53%/60% normal weight, 19%/18% overweight, and 26%/20% obese, respectively. Among obese tenth-graders, 83% had been obese as fifth-graders and 13% had been overweight. Sixty-five percent of obese fifth-graders remained obese as tenth-graders, and 23% transitioned to overweight. Multivariately, obese fifth-graders who perceived themselves to be much heavier than ideal (P = .01) and those who had lower household education (P = .006) were less likely to exit obesity; by contrast, overweight fifth-graders were more likely to become obese if they had an obese parent (P < .001) or watched more television (P = .02).


CONCLUSIONS
Obese fifth-graders face challenges in reducing obesity, especially when they lack advantages associated with higher socioeconomic status or when they have a negative body image. Clinicians and others should educate parents on the importance of preventing obesity very early in development. Children who are not yet obese by fifth grade but who have an obese parent or who watch considerable television might benefit from monitoring, as might children who have negative body images.
Division of General Pediatrics, Department of Medicine, Boston Children's Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts; RAND Corporation, Santa Monica, California; mark.schuster@childrens.harvard.edu.
Mark A
MA
Schuster
RAND Corporation, Santa Monica, California;
Marc N
MN
Elliott
Division of General Pediatrics, Department of Medicine, Boston Children's Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts;
Laura M
LM
Bogart
Division of General Pediatrics, Department of Medicine, Boston Children's Hospital, Boston, Massachusetts;
David J
DJ
Klein
Division of General Pediatrics, Department of Medicine, Boston Children's Hospital, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts;
Jeremy Y
JY
Feng
Psychological Sciences, University of California, Merced, California; and.
Jan L
JL
Wallander
Center for Health Promotion and Prevention Research, School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas.
Paula
P
Cuccaro
Center for Health Promotion and Prevention Research, School of Public Health, University of Texas Health Science Center at Houston, Houston, Texas.
Susan R
SR
Tortolero
D000293:Adolescent; D000367:Age Factors; D001828:Body Image; D015992:Body Mass Index; D002648:Child; D005260:Female; D006306:Health Surveys; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D050177:Overweight / Q000175:diagnosis / Q000453:epidemiology*; D012307:Risk Factors; D012959:Socioeconomic Factors; D013851:Thinness / Q000175:diagnosis / Q000453:epidemiology; D014481:United States; D014505:Urban Population / Q000639:trends*
BMI; adolescence; childhood; longitudinal study; obesity