June 16/USA TODAY -- Obesity is "the single greatest threat to public health in this century," an expert panel declared in a report that urges Americans to slash calories and increase their physical activity.

An advisory committee for the 2010 Dietary Guidelines for Americans calls on people to cut back on added sugars and solid fats (butter, marbled meats) and to follow a more nutrient-rich, plant-based diet.

The report is based on the latest scientific evidence and was prepared by a 13-member panel of national nutrition and health experts. The public now has 30 days to comment at www.dietaryguidelines.gov.

The final 2010 dietary guidelines will be released later this year by the U.S. Department of Agriculture and Department of Health and Human Services.

About two-thirds of adults and one-third of children in the U.S. are overweight or obese. The advisory committee highlighted four major steps:
* Reduce excess weight and obesity by cutting calorie intake and increasing physical activity.
* Shift to a more plant-based diet that emphasizes vegetables, cooked dry beans and peas, fruits, whole grains, nuts and seeds. Increase the intake of seafood and fat-free and low-fat milk and milk products, and eat only moderate amounts of lean meats, poultry and eggs.
* Significantly reduce intake of foods containing added sugars and solid fats, which contribute about 35% of the calories in the American diet. Cut sodium intake gradually to 1,500mg a day and lower intake of refined grains, especially those with added sugar, solid fat and sodium.
* Meet the 2008 Physical Activity Guidelines for Americans. Those recommend that adults get at least 2.5 hours of moderate-intensity physical activity each week, such as brisk walking, or 1.25 hours of a vigorous-intensity activity, such as jogging or swimming laps, or a combination of the two types. Children and teens should do an hour or more of moderate-intensity to vigorous physical activity each day.

The report calls for many changes in the food environment, including:
 *Improve nutrition literacy and cooking skills, and motivate people, especially families with children, to prepare healthy foods at home.
* Improve the availability of affordable fresh produce through greater access to grocery stores, produce trucks and farmers' markets.
* Encourage restaurants and the food industry to offer health-promoting foods that are low in sodium; limited in added sugars, refined grains and solid fats; and served in smaller portions.

The dietary guidelines were first published in 1980 and are updated every five years. They are used for government nutrition programs and education, as well as by dietitians and health professionals to help educate people about eating healthier.

"Basic nutrition advice hasn't changed much over the 30 years that the dietary guidelines have been published, but what has changed is it is harder and harder to eat well," says Margo Wootan, director of nutrition policy at the Center for Science in the Public Interest, a consumer group based in Washington, D.C.

From the June 21, 2010, Prepared Foods E-dition