quarta-feira, 25 de agosto de 2010


The government, as well as many health and nutrition groups, wants to give people the information they need to make healthy food choices. In 1992, the USDA (United States Department of Agriculture) adopted the nutritional guide that was created at Tufts University. It is in the shape of a pyramid, to help people remember what food to eat. The pyramid looks like this:
This pyramid shows different food groups, and the servings you should have of each. For example, you should have 6 to 11 servings a day of foods in the Bread, Cereal, Rice & Pasta Group. Examples of servings in this group are one slice of bread, 1/2 cup of cooked cereal, rice or pasta, or one cup of ready-to-eat cereal. Examples for the Fruit Group include a medium-sized apple, orange or banana, 3/4 cup of fruit juice or 1/2 cup of chopped, cooked, or canned fruit. In the Vegetable Group examples of a serving are a cup of raw, leafy vegetables, 1/2 cup of other vegetables, cooked or raw, or 3/4 cup of vegetable juice. For the Meat, Poultry, Fish, Dry Beans, Eggs & Nuts Group, they suggest a serving of two to three ounces of meat, fish or poultry. In addition, the following would count as one ounce of the same category: one egg, 1/2 cup of cooked beans, 2 tablespoons of peanut butter, or 1/3 cup of nuts.
Notice that the bottom of the pyramid, the biggest part, is the Bread, Cereal, Rice & Pasta Group. This pyramid shows that that is where you should get the most servings per day. The top part, the Fats, Oils & Sweets Group is the smallest. That shows that you shouldn't have too much fat or oil in your diet.
While a lot of the food pyramid was a good idea, and the visual picture helped people remember not to have too much fat and oil, a lot of nutritionists didn't think the pyramid did a good job of showing some other nutritional facts. They thought there were some problems with the pyramid.
One problem was that there was no difference made between whole grains and refined grains or between saturated and unsaturated fats. While it might be good to have some olive oil, for example, eating food made with shortening isn't a good idea. In addition, while four slices of whole grain bread could be pretty healthy, four slices of white bread made from refined wheat aren't as nutritious. A serving of non-fat milk is just as nutritious and better for you than a serving of whole milk. Another problem with the pyramid was that in some cases the servings mentioned were supposed to be a maximum (like for the meat group) but in other cases they were supposed to be a minimum (like for the fruit group). Finally, the food pyramid didn't show the importance of exercise or the need to watch the size of your portions. There was also some discussion about the fact that it was the U.S. Department of Agriculture, and not the U.S. Department of Health and Human Services that made the pyramid. Some people said the number of servings of fruits and vegetables, for example, was higher than the number used by the World Health Organization, and maybe it was because the USDA wanted people to eat more of those products for business reasons instead of health reasons.
In April 2005, the USDA replaced the original pyramid with another pyramid by turning it on its side and making the sections vertical instead of horizontal. The new pyramid looks like this:
Looking at this pyramid, you can see that there are different colored parts of the pyramid, but each one gets smaller as it goes toward the top. The part toward the top is for the less healthy foods in the category, and the part at the bottom is for the healthier foods. For example, you might put whole milk at the top of the Milk group, and non-fat milk at the bottom; or you could put whole grains at the bottom of the Grains group and refined grains at the top. The parts of the pyramid also show how important they are by the width of the band. The small yellow one that has no name on the bottom contains fats and oils. The unsaturated oils, like peanut, canola, or olive, would be at the bottom. Butter would be at the top. The person climbing the steps on the left side of the pyramid symbolizes the importance of exercise.
You can go to mypyramid.com to get current information about the USDA pyramid, or you can click on the link to My Pyramid Plan to put in your personal information and get a customized food guide.
Faculty members at the Harvard School of Public Health made an alternate pyramid, which they called the Healthy Eating Pyramid. It includes more information based on all the research on nutrition that has taken place in the last fifteen years. The pyramid looks like this:
Notice this pyramid has a section on the bottom called Daily Exercise and Weight Control. It is built this way to show that daily exercise and weight control are the foundation for good health.
Every five years the USDA reviews the nutrition advice in the Dietary Guidelines for Americans. This document sets the standards for all federal nutrition programs, such as the school lunch program, and also can influence what foods people buy. That's why the food industry and nutrition experts are all interested in seeing how the guidelines might be changed. It was last reviewed in 2005, and will be reviewed again in 2010. In 2005, there were several changes. Instead of just saying that all dietary fats are bad, the suggestion now is that trans fats should be avoided, and saturated fat should be limited, but a person can get between 20 and 35 percent of their daily calories from monounsaturated and polyunsaturated fats. The new guidelines also suggest that people limit their intake of sugar, and try to increase their intake of whole grains.
The Harvard School of Public Health says that there is a problem because the nutrition guidelines, in talking about protein, currently don't distinguish between red meat, poultry, fish, or beans, including soy products. They say that recent studies show that replacing red meat with a combination of fish, poultry, beans and nuts can have a beneficial effect on health.
Finally, they say that the recommendation to drink three glasses of low-fat milk or eat three servings of dairy products every day may not be a good idea. They explain that some people are lactose-intolerant, and get stomachaches from milk products. Other people are trying to lose weight and the calories in the milk make it difficult.
The "use sparingly" part at the top of the pyramid is different in this version. It includes refined grains; that is, white bread, rice and pasta, as well as potatoes, salt, sugary drinks and sweets because they are not good in large quantities. They also suggest a multivitamin to fill in any holes in case you don't get enough vitamins and minerals in food. Finally, they have alcohol listed in moderation, usually one or two drinks for men and one drink for women per day. There is some evidence that a small amount of alcohol may have some health benefits especially for middle-aged people. However, it is not recommended for pregnant women, or for people who can't stop at one drink.
In summing up their recommendations, they say the best thing to remember is to eat more of the foods toward the bottom of the pyramid and less of the foods at the top. They suggest avoiding trans fat altogether, and limiting the amount of processed food--canned soups, frozen dinners, snack chips, etc., because they are usually very high in sodium.

When you finish reading this article, click here to take the quiz. It will be in a new window.


Nenhum comentário:

Postar um comentário