Study: Kids Don't Outgrow Baby Fat

May 5, 2006 — -- Parents often think their overweight kids will simply "grow out of it" and shed those extra pounds -- often called "baby fat" or "puppy fat" -- when they mature.

A new study from the British Medical Journal, however, says that a child who is overweight at the age of 11 will very likely leave high school overweight.

The study looked at the body mass index and waist circumference of a diverse group of more than 5,000 students over five years in 36 London schools. The study found that the obese children rarely achieved a normal weight, which, the report says, "indicates that any notion of 'puppy fat' that disappears on maturation must be abandoned."

Of the group of students the British researchers studied, 25 percent were overweight or obese at the outset of the study, with the remaining 75 percent at a healthy weight. That proportion never changed: The percentage -- 7.6 percent -- of overweight or obese students who lost enough weight to achieve a normal weight was very similar to the number who gained enough weight to move from normal weight to overweight/obese -- 7.0 percent. Also, some of the overweight students became obese.

Adolescence has long been seen as a critical time for children to watch their weight, but this study shows that kids enter adolescence with their weight problems and that those problems stay. Experts say it's never too soon for kids to watch their weight.

"We need to hit these kids really way before this time period and in preschool, in kindergarten, in early elementary school," said Dr. Francine Kaufman, director of the Comprehensive Childhood Diabetes Center and head of the Center for Endocrinology, Diabetes and Metabolism at the Los Angeles Children's Hospital.

The study, led by Jane Wardle, professor of clinical psychology at the Cancer Research UK Health Behaviour Unit at University College London, also found ethnic background made a significant difference in weight for girls, but not boys. The heaviest group were black girls --