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Risk factors for childhood obesity


In response to the increase in childhood obesity, this study assesses associations between physical activity, diet, socio-economic status and overweight in children.


Perhaps not surprisingly, physical inactivity (measured by television viewing and sports participation) and unhealthy eating habits are associated with overweight in children. Overweight is also associated with coming from a low socio-economic background, suggesting that these families should be a primary target for awareness and prevention campaigns.


MJ Muller et al. Physical activity and diet in 5 to 7 years old children. Public Health Nutrition 1999 2 443-444.


Between 1995 and 1998 1,497 children (739 boys and 758 girls) aged between five and seven years old completed a food frequency questionnaire (from which a diet quality index was calculated) and underwent a body composition analysis. Overweight was defined as a triceps skinfold thickness of more than 90 mm. Parents also provided information on physical activities, television viewing time and social status (defined by education level).

Twenty three percent of the children were overweight. There were no differences in the diet quality index between overweight and normal weight children.


There was an association between physical activity (measured by television viewing time and participation in sports activities) and body mass index (kg/m2). As television viewing increased and sports activities decreased, body mass index increased (see Figure 1).

Television viewing of more than one hour a day was associated with a high consumption of fast foods and sweets, compared with viewing of less than an hour a day.

Overweight, inactivity and unhealthy eating habits were seen more frequently in children from low socio-economic backgrounds. Figure 2 shows the association between body mass index and socio-economic level.


This paper did not provide enough information to be able to judge the quality of the results (e.g. how television viewing and sports participation were assessed). Nevertheless, the results are noteworthy. They show the associations between increased television viewing time, physical inactivity and unhealthy eating habits, and overweight. Perhaps more interestingly, they also show the higher prevalence of overweight in children from lower socio-economic backgrounds suggesting that initial prevention efforts should be targeted to these families.