Programming obesity and poor fitness: the long-term impact of childhood television.
OBJECTIVE
To assess whether the long-term effects of childhood television viewing on BMI and cardiorespiratory fitness are mediated by adult viewing.


METHODS
This prospective study included an unselected birth cohort of 1,037 participants (535 men) born in Dunedin, New Zealand in 1972/1973. Hours of television viewing on weekdays were reported at ages 5, 7, 9, 11, 13, 15, and 32 years. BMI and cardiorespiratory fitness were measured at age 32 years.


RESULTS
Both childhood and adult television viewing times were significantly associated with higher BMI and lower cardiorespiratory fitness at age 32 years. Childhood television viewing was a better predictor of adult BMI and fitness than adult viewing and remained a significant predictor of these outcomes after adjusting for adult viewing time. After adjusting for adult viewing, the odds (95% confidence interval) of adult obesity increased by a factor of 1.25 (1.01, 1.53) and poor fitness increased by a factor of 1.40 (1.16, 1.70) for each hour of mean weekday television viewing during childhood.


CONCLUSIONS
The association between childhood television viewing and obesity and poor fitness in adulthood is not mediated by adult viewing. The detrimental health effects of watching too much television during childhood persist into adulthood. Attempts to reduce adult obesity and poor fitness by modifying television viewing habits need to begin in childhood.
Erik Landhuis
C
C
Dunedin Multidisciplinary Health and Development Research Unit, Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
Poulton
Richie
R
Welch
David
D
Hancox
Robert J
RJ
D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D006184:Habits; D006801:Humans; D008019:Life Style; D008297:Male; D009765:Obesity / Q000503:physiopathology*; D010809:Physical Fitness / Q000502:physiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013690:Television; D013997:Time Factors