The new dietary guidelines will be used to update the familiar food pyramid, which most people recognize but few heed. The revision will be the pyramid's first since it was created 12 years ago.
The new guidelines stress choosing sensibly, reports CBS News Correspondent Elizabeth Kaledin.
The advice is not really new. But Americans don't heed it, so the government sees the guidelines as an opportunity to change people's ways.
"In the past we haven't had a lot of advice about portions. That's going to be stressed more in the dietary guidelines," Parenting magazine health editor Robert Barnett said.
"The guidelines offer Americans achievable goals for controlling weight," said Tommy Thompson, secretary of Health and Human Services, which developed the guidelines with the Agriculture Department. "Let's start today."
Thompson noted that two in three Americans are overweight or obese and suggested that the guidelines are well timed, coming in January, soon after many have made New Year's resolutions to live healthier lifestyles.
The guidelines strengthen the government's advice on whole grains, telling people to choose whole grains such as whole wheat bread instead of refined ones like white bread or bagels.
People should also eat a lot more vegetables and fruit, the guidelines said.
And now, as Kaledin reports, food producers and packaging manufacturers are looking to fit the new mold.
"Certainly the food companies are scrambling to figure out how to promote their food products as more healthful whether or not they really are," said nutritionist Marion Nestle.
The government recommended three one-ounce servings of whole grains each day, such as certain unsweetened breakfast cereals, to reduce the risk of heart disease and help maintain weight.
"Eating fewer calories while increasing physical activity are the keys to controlling body weight," the guidelines said.
The new guidelines also encourage people to eat whole fruits and vegetables rather than fruit and vegetable juices.
Agriculture Secretary Ann Veneman said the popularity of diet books and products shows that "Americans are interested in leading healthier lives, but they want credible, consistent and coherent information to help them make the best possible choices."
The advice is not really new, but the government sees the guidelines as an opportunity to change people's ways.
"It has been a big problem in the past that basically, the federal government has published a booklet and then crossed their fingers and hoped that Americans ate better," said Margo Wootan, nutrition policy director for the Center for Science in the Public Interest, a health advocacy group.
"That's clearly not been enough. What we need is significant investment in programs and changes in policy and the food environment that help Americans to eat better and watch their weight," Wootan said.
The guidelines were based on recommendations of a 13-member panel of scientists and doctors who spent nearly a year reviewing Americans' diet and health.
The committee said people lead sedentary lifestyles and choose their food poorly, leading many to exceed the calories they need even as they fail to get enough nutrition.
Controlling calories — not limiting carbohydrates, as some popular diets recommend — is key to controlling weight, the panel said.
"Eating too much sugar is a significant cause of obesity, and sodas and other things like that, in children particularly, is a big problem," Barnett told Raviv.
Also key is daily exercise. The panel recommended a minimum of at least 30 minutes of moderate exercise — brisk walking or gardening — on most days.
But it said many adults need to exercise for 60 minutes or more to prevent weight gain, and people who have lost weight may need to exercise for 60 to 90 minutes to keep it off.
The panel said to choose fats and carbohydrates wisely. That means severely restricting trans fat that can clog arteries and eating fiber-rich whole fruits and whole grain breads. People should eat five to 13 servings each day of fruits and vegetables, depending on their age and level of activity, the panel said.
The committee recommended cups rather than serving sizes in many instances; by this measure, the average person would need 4½ cups of fruits and veggies to maintain his or her weight.
That might sound like a lot, but it's easy to do, said Robert Earl, senior director for nutrition policy for the National Food Processors Association.
"Let's say you drink a serving of orange juice, you eat a banana, you have a salad with one of your meals, and at dinner, you have a vegetable," Earl said. "I'll bet you're at close to 4 cups already, if not more. The important thing is to move consumers in the right direction."
The panel also said people need to reduce the amount of salt they eat to about one level teaspoon each day — salt is linked to high blood pressure — and those who drink alcohol should drink in moderation, about one drink each day for women and two for men.