About 20 percent of children in the United States will be obese by 2010 if dramatic steps aren't taken to halt childhood obesity, says a report released Wednesday by the prestigious Institute of Medicine.

It declares that efforts now being made in the United States to improve children's diets and increase their physical activity are "fragmented and small" and recommends that the president appoint a high-level task force to address the problem by coordinating the efforts and resources of federal agencies.

About 17 percent of children and teens in the United States are obese; an additional 16.5 percent are on the brink of becoming so, the report says. Extra pounds put children at an increased risk of being overweight adults and developing type 2 diabetes, high cholesterol, heart disease and other health problems.

The problem is one of the 21st century's "most critical public health issues," says Jeffrey Koplan, chairman of the report committee and former director of the Centers for Disease Control and Prevention. "There is no one segment of society that's going to solve this alone. It has to be a concerted, coordinated effort. That's one of the things that's missing now."

The report calls on parents to work harder to encourage healthful eating and regular physical activity at home and the food industry to market more nutritious products.

It suggests the development of a community health index to evaluate kids' access to physical activity and healthful foods such as fruits and vegetables. And it recommends continuing the government's VERB health promotion and ad campaign, which is designed to get children moving more but has lost its federal funding.

Children need more ways to exercise, Koplan says. They can still "play sandlot baseball and ride their bikes in the neighborhood, but we also have to come up with alternative ways to enable kids to be active, even while they are in the house."

Obesity experts say they hope the report will make a difference. "There's a lot of hand-wringing about childhood obesity, but the current national response is like putting a Band-Aid on a brain tumor," says Margo Wootan of the Center for Science in the Public Interest, a consumer group. "There are little things going on here and there, but there isn't the coordinated national action that is needed.

"We need a whole shift in thinking about how often to eat, what to eat and how much to eat."

To help parents feed their children well, Wootan says, "we need calorie labeling on menus at chain restaurants, and we need to stop marketing unhealthy foods to kids on TV, the Internet, in food packages and in schools."

James Hill, co-founder of America on the Move, which encourages increased physical activity, says: "The time for action is now. This is a problem that affects all of society, and it's time to get all of society involved in addressing it."

Risa Lavizzo-Mourey, president of the Robert Wood Johnson Foundation, the report's sponsor, agrees. "If we do not reverse the epidemic of childhood obesity, millions of our children, and the whole of our society itself, will be robbed of a healthy and hopeful future."

Psychologist Kelly Brownell of the Rudd Center for Food Policy and Obesity at Yale University says, "This report is a real advance because it explicitly states that government is doing too little and action needs to be ramped up a lot."