Every time you look at a newspaper, you read about obesity. And everywhere you look, you see fat people. Now we're supposed to worry about chubby babies?

The increase in overweight children over age 2 has been recognized for several years. But the obesity epidemic has even affected babies, and we know that many overweight babies grow into obese adults. Like most parents, my wife and I were pleased at the sight of our fat-cheeked, chubby first daughter. Fortunately, she did not end up as an obese adult.

One study carried out in Massachusetts compared the weights of babies in 1980 and in 2000. The percentage of babies who were overweight at less than 6 months of age had quadrupled, from 1.4 percent in 1980 to 5.9 percent in 2000. Among children between 6 months and 2 years in 2000, a bigger proportion were overweight than in the 1980 group, but the percentage increase was smaller at this age.

There's a debate in the medical community about the growth charts used by virtually all American pediatricians. These charts compare an individual child with an average American child, whether the average growth rate is healthy or not.

But if children are measured against new child growth charts released by the World Health Organization, even more American babies would fall into the overweight category. The new charts are designed to define how children should grow rather than how they are growing.

The harmful health effect of weighing too much as a child is most apparent in the rising number of obese adolescents with type 2 diabetes. Fifteen years ago, I could predict with near certainty that any teenager with diabetes had type 1 diabetes, the form of the disease that results when the pancreas cannot produce insulin.

Now, a sizeable portion of teenagers with diabetes are extremely obese and have type 2 diabetes, caused by obesity-induced resistance to the action of insulin combined with poor insulin production by the pancreas.

Of course, when obese children grow into obese adults, as many of them will, they'll face many other health problems, especially heart disease. Studies by the American Cancer Society also estimate that about 15 percent of all cancers are caused by obesity.

Unfortunately, it's not clear what parents can do to stop very young babies from weighing too much. Putting a baby on a diet is not the answer, because the fats in whole milk are needed for healthy development of the infant's brain and other organs.

Mothers should bring up their concerns with the child's pediatrician, who can suggest solid foods that will help a baby grow healthy instead of fat. (Breastfeeding has been associated with less overweightedness in infants.) I agree with the recommendation that switching to 1 percent milk after a child's second birthday may help prevent further weight gain.