Preschool children are less likely to become obese if they regularly eat dinner with the rest of the family, get adequate sleep and limit television watching time.

In a large US sample, the study showed that four-year-olds living in homes with all three routines had an almost 40 percent lower prevalence of obesity than did children living in homes that practised none of these routines.

Sarah Anderson, assistant professor of epidemiology at Ohio State University (OSU) and her counterpart Robert Whitaker, paediatrics professor, analysed data collected in 2005 on 8,550 children who were born in the US in 2001.

Other studies have linked obesity to the individual behaviours of excessive TV viewing, a lack of sleep and, to a lesser extent, a low frequency of family meals.

But this is the first study to assess the combination of all three routines with obesity prevalence in a national sample of preschoolers.

Researchers suggested that adopting these three household routines could be an attractive obesity-prevention strategy for all families with young children, especially because these routines may benefit children's overall development, said an OSU release.

However, they also cautioned that this study alone does not confirm whether the routines themselves, or some other factor, protect children from obesity.

The study is slated for publication in the March issue of Paediatrics.