By the time they are 6 years old, children of overweight mothers are more likely to be obese than children of lean mothers, according to a study in the January issue of the American Journal of Clinical Nutrition (2005; 81 [1], 140–46).

Researchers tracked 70 children over a 6-year period at The Children’s Hospital of Philadelphia and the University of Pennsylvania. Thirty-three had overweight mothers, and 37 had lean mothers. Weight and body composition didn’t change much between the two groups during the first 2 years of age. However, the high-risk group (kids whose mothers were overweight) had gained more weight than the other group by age 4. By age 6 the high-risk group not only weighed more but had more body fat.

Researchers pointed to the strength of genetic influences and suggested that efforts to prevent obesity should focus on such children at risk, preferably by the time they are 4 years old.