The food pyramid is designed to make eating choices as straightforward as possible, reports medical correspondent Dr. Emily Senay on Thursday's The Early Show.
As it stands now, at the bottom are foods we should eat the most of: breads, cereal, rice and pasta, moving up to lesser amounts of fruits and vegetables, and on up to even lesser amounts of dairy and protein. At the top are foods that should be eaten only sparingly: fats, oils and sweets. Dr. Walter Willett of the Harvard School of Public Health says the pyramid needs a radical overhaul.
"The present food pyramid really is virtually useless, and for some people, it can actually be dangerous", says Dr. Willett. "Some people who follow the pyramid and give up all types of fat in the diet can actually be harming themselves because they can be avoiding the healthy fats that help reduce cholesterol and help prevent heart disease."
Dr. Willet suggests a pyramid in which daily exercise gets the most emphasis, followed by plenty of good fats like plant oils, and plenty of fiber-filled whole grains. Next is vegetables and fruits. Then comes protein in the form of nuts and legumes, and fish, poultry and eggs. Next is dairy or calcium supplements. Unhealthier items like red meat, butter, sweets, potatoes, white rice, white bread and pasta should be eaten only sparingly.
"What's really important is to emphasize healthy fats, healthy carbohydrates and deemphasize unhealthy fats and unhealthy carbohydrates. The present pyramid completely fails to do that," Dr. Willet says.
That kind of talk has some food lobbyists on the defensive. Changes to the pyramid could put the potato in danger of losing its prime spot at the bottom of the pyramid. The U.S. Potato Board is lobbying to keep it there.
"We're in the vegetable group and we should stay in the vegetable group and obviously people need to eat more fruits and vegetables and potatoes are a great way to get that done," says the Potato Board's Lisa Katic.
However, Dr. Willet disagrees. "The food pyramid really should be based on the best available scientific evidence," he says. "There's plenty of evidence now that large amounts of carbohydrates - like white bread and crackers and pasta and white rice and potatoes - have bad metabolic effects."
The USDA is opening up the debate to the public before making a final decision, expected early next year. An advisory committee has already recommended that more exercise and fewer calories from unhealthy fats and carbs and more of the healthy ones should be a part of a new pyramid. They are also recommending less salt. It seems that change is in the air.
A lot of the emphasis is on weight control, because so many health problems are a result of weight. So it all comes back to diet and exercise, maintaining energy balance. We have to burn off the calories we eat, so exercise and portion size are key.
The pyramid doesn't exclude the things that can be bad for you, which is realistic. "Use sparingly" means everyone is represented and no food needs to be completely eliminated.