To curb the childhood-obesity epidemic, health experts have long urged parents to make healthy changes to their family's lifestyle -- such as eating nutritiously, reducing TV time, exercising and getting a good night's sleep.

Individually, these behaviors have been linked to a lower risk of obesity in kids, but researchers at Ohio State University were interested in learning whether their effect might be cumulative -- that is, whether families who adopted not just one but two or more of these behaviors could reduce their children's risk of obesity even further.

Led by epidemiologist Sarah Anderson, researchers analyzed data on 8,550 4-year-olds in a national study and found that, indeed, children who practiced two healthy lifestyle behaviors were slimmer than those who adopted only one behavior, while youngsters who implemented three beneficial habits were the least likely to be overweight. "The more of these routines the children had, the lower was their risk of obesity," Anderson says. "If children had all three routines, their risk of obesity was 40% lower than children who had none of the routines."

The three behaviors Anderson studied were eating dinner regularly with the family, limiting the amount of time spent in front of the TV, and getting enough sleep. The children who were least likely to be obese ate dinner with their families six or seven times a week, slept for at least 10.5 hours each night and watched less than two hours of television per day.