Couch Potatoes May Start as Tater Tots Jan. 15, 2004 -- The couch potato lifestyle now associated with scores of diseases may begin with being a tater tot. A new study shows sedentary habits that boost the risk of obesity can be apparent in children as young as age 3.

After randomly recruiting 78 children, Scottish researchers noted that these 3 year olds typically spent only about 20 minutes a day in light or moderate activity -- only one-third the time recommended in the United Kingdom for kids that age. When they were re-evaluated at age 5, their activity patterns barely improved.

"There is a widespread perception among parents and health and education professionals that young children are spontaneously active," says researcher John J. Reilly, PhD, of the University of Glasgow. "We have provided objective evidence that present recommendations for physical activity are not being met by many young children."

More importantly, when Reilly and his colleagues measured the kids' energy expenditure, they found that these kids burned off 200 calories a day less than what is recommended. That means that unless they eat that much less in food, they're more likely to join the ever-expanding ranks of the obese years before their time.

As a general rule, people gain one pound for every 3,500 calories consumed that they don't burn off. Conversely, we lose about a pound for each 3,500 calories lost in exercise or other activity. "Weight gain could occur from as little as 20 to 50 calories a day ingested in excess of energy expanded," write the researchers in this week's issue of The Lancet.

While this doesn't show that all preschoolers are en route to obesity, it does offer an explanation as to why childhood obesity is on the increase in U.K., as it is in the U.S.

That's why this study has important implications, says James Hill, PhD, of the University of Colorado Health Sciences Center, who wasn't involved in Reilly's study but wrote an accompanying editorial to it.

"As people get older, they become less active. It's very unlikely that sedentary children will become active adults," Hill tells WebMD. "When kids start off at a lower level of physical activity, it's probably going to only further decline over their lifetime. From everything we know, this study suggests that these kids will be sedentary adults."