Experts are trying to work out new rules on which foods to eat and which ones to avoid.
It's lunchtime, and you're hungry.
You have two choices. You can eat whole-grain rice, a big heap of steamed broccoli, and a grilled, skinless chicken breast. Or you can have french fries, a cheeseburger, and a chocolate milkshake. Which meal would you choose?
These are the kinds of decisions you'll have to make several times a day for the rest of your life. Carrot sticks or potato chips? Milk or soda? An apple or a candy bar?
Even when you know which choice is better for you, it still may be hard to resist foods that you find especially tasty. For many Americans, this means fried food, cookies, candy, and soft drinks.
All this sugar and fat, though, is starting to add up. Obesity is a growing problem in countries around the world. As waistlines expand, diabetes, heart disease, cancer, and other health problems are becoming more common—even among kids.
Scientists who study nutrition want to put an end to this alarming trend. Even governments are getting involved. They want to help people stay healthy and to keep healthcare costs from spiraling higher.
For years, the United States government has recommended how much of different kinds of foods people should eat. You often see that advice displayed as a food pyramid. Foods near the bottom should be eaten much more often than those near the top.
A food pyramid is one way to suggest which foods you should be eating the most.
Now that scientists have learned a lot more about which foods are good for you and which ones cause diseases, the government is updating its guidelines. There'll be new food advice by early next year—and maybe you'll see a square, rectangle, or wheel instead of a pyramid!
It's never too early to start eating well, says Mary Story. She's a nutritionist at the University of Minnesota in Minneapolis.
"What you eat now is certainly important for what you'll become," she says. "Eating healthy is also important for right now. It's tied directly to your energy level, to the quality of your skin and hair, to feeling and looking good."
With these points in mind, the U.S. Department of Agriculture created the Food Guide Pyramid in 1992. Its shape was meant to illustrate the proportions of foods that should make up a healthy diet.
At the very top of the pyramid, where there isn't much room, are foods that shouldn't take up much room in your diet. Foods such as oil, butter, and sweets, for example, are best eaten in small quantities. Studies show that an overly fatty diet leads to heart disease and obesity.
The Food Guide Pyramid suggests how many servings of different kinds of foods you should eat each day.
One level down in the pyramid, where the triangle gets a little wider, are foods that are best eaten in moderation. The current pyramid recommends two to three servings from the milk, cheese, and yogurt group. These foods contain calcium, which strengthens bones and prevents osteoporosis (see Strong Bones for Life).
The Food Guide Pyramid also recommends two to three servings of protein, such as fish, beans, eggs, nuts, or chicken. Protein is important for your muscles, blood, immune system, and various processes in your body.
Another step down, the pyramid calls for three to five servings of vegetables and two to four servings of fruit. Fruits and vegetables are full of fiber, vitamins, and minerals that have been shown over and over again to prevent cancer, heart disease, and other ills.
At the bottom of the pyramid, where the triangle is widest, sit breads, cereal, rice, pasta, and other starches. You should eat six to 11 servings of these kinds of complex carbohydrates every day.
Changing the pyramid
The pyramid's basic structure still makes sense to most nutritionists. Nonetheless, the U.S. Department of Agriculture has received plenty of criticism.
Story, for one, hopes the next pyramid will emphasize whole grains and high-fiber starches in the bread category. Studies have shown that whole-grain foods are much better for you than refined products and white bread.
The pyramid categories also invite confusion. Does apple pie, for example, belong with sweets or fruits?
Another problem is portion size. There's a lot more supersizing of meals, for instance, than there used to be.
The next pyramid should be more specific about how big a serving is, Story says. Body size and activity level determine the number of calories people really need and the kinds of foods they should eat.
"A bagel at some of the bagel chains can be four servings of bread," Story says. "But people have no idea that bagels can be that dense." Eating foods in the right proportions doesn't help much if people are still eating too much.
To come up with up-to-date food advice, a panel of 13 experts is now gathering information, arguing about evidence, and considering comments from the public.
People have offered all sorts of suggestions. A nutrition student from the University of the District of Columbia, for example, was one of many who wrote that the pyramid should encourage people to drink lots of water.
Other people thought the pyramid should distinguish between different kinds of fats. Saturated fats, found in butter, donuts, and many kinds of cookies, can lead to heart disease when eaten in large quantities.
Fats in nuts, seeds, and some fish, on the other hand, can help prevent disease. Eating nuts can actually help people stay slim, recent studies show. They keep you full longer, so you eat less.
Where would a pizza fit in the current food pyramid? With the grains? vegetables? cheeses?
Some people, including vegetarians, choose to eat soy products, such as tofu, tempeh, and soy milk, instead of meat and dairy products. "Why is tofu not listed on the Food Guide Pyramid?" one person asked. "This is a complete protein, it's low in fat, and it has vital minerals, such as calcium and iron."
Another person suggested that the guidelines should warn against canned fruits and vegetables. These products often have large amounts of added sugar and salt.
Others wrote that exercise should earn a slot at the pyramid's base. Physical activity is good for the heart and muscles, it can boost moods, and it prevents obesity, among other health benefits.
The expert panel building the new Food Guide Pyramid has a tough job. The panel members have to choose among all these suggestions and come up with recommendations based on solid scientific evidence. The new food guide might not even fit comfortably into a pyramid.
Of course, simply telling people what they should eat doesn't mean they'll do it.
In a study based on data collected in 1999 and 2000, the U.S. Department of Agriculture's Center for Nutrition Policy and Promotion found that only 10 percent of people had a healthy diet. The rest needed to improve their diets, especially by eating more fruit and dairy products.
Bad habits start early. Most surveys estimate that kids eat less than half the recommended amount of vegetables each day. Among the vegetables that kids and teenagers do eat, french fries make up a whopping 25 percent.
Just one child out of five eats five or more servings of fruit and vegetables each day, according to a recent study by scientists at Harvard University. And they found a curious trend: The more TV kids watch, the fewer fruits and vegetables they eat.
So, try turning off the TV and start thinking about the Food Guide Pyramid next time you have to decide what to eat. Have an apple or orange after every meal. Drink milk or juice instead of soda. Eat whole wheat bread. Snack on carrot sticks rather than potato chips. Cut down on cookies and candy.
"You are what you eat," the old saying goes. When the new guidelines come out, scientists hope we'll all use them to live longer and healthier lives.