Food pyramid (nutrition)

The current food pyramid

The food guide pyramid was the previous nutritional guide (created at Tufts University School of Medicine) of the USDA, replaced in April 2005 by the new USDA nutrition advisory program titled "MyPyramid".. The food guide pyramid was surprisingly not created with the involvement of the Department of Health and Human Services, which would be expected for most matters involving human health. This has resulted in criticism stating that the real purpose of the new recommendations is to improve the economic position of US grain producers and not the health of the population.

File:Weightloss pyramid.JPG

A weight loss pyramid made on the model by BCM

The food guide pyramid, informally known as the food pyramid, and formally titled the Improved American Food Guide Pyramid, was published in 1991 to replace the earlier food groups classification system. Since that time there has been an epidemic increase in type 2 diabetes which is now even afflicting a large and rapidly increasing number of children. The food guide pyramid suggested optimal nutrition guidelines for each food category, per day, using a mnemonic graphic of a pyramid with horizontal dividing lines, to represent suggested percentages of the daily diet for each food group.

Food Groups according to the Food Guide Pyramid

Grains Group

Bread, Cereal, Rice, and Pasta are grown from cereal crops. Cereals, breads, pastas, crackers, and rice all fall under this categorization. Grains supply food energy in the form of starch, and are also a source of protein. Whole grains contain dietary fiber, essential fatty acids, and other important nutrients. Milled grains, though more palatable, have many nutrients removed in the milling process and thus are not as highly recommended as whole grains. Whole grains can be found especially in oatmeal, brown rice, grits, corn tortillas and whole wheat bread. 6-11 servings of grain products are recommended per day. Starch is the most valuable polysaccharide. The starch molecule is tree-like, with branches of varying length. Starch digestion begins in the mouth with salivary amylase, continuing in the small intestine with pancreatic amylase. Short chains of glucoses are referred to as alpha-dextrin, maltotriose (3GL), and maltose (2GL). Glucoamylase breaks these short chains down.

Vegetable Group

A vegetable is a part of a plant consumed by humans that is generally savory (not sweet) and not considered grain, fruit, nut, spice, or herb. For example, the stem, root, flower, etc. may be eaten as vegetables. Vegetables contain many vitamins and minerals; however, different vegetables contain different spreads, so it is important to eat a wide variety of types. For example, green vegetables typically contain vitamin A, dark orange and dark green vegetables contain vitamin C,and luxuriant vegetables like broccoli and related plants contain iron and calcium. Vegetables are very low in fats and calories, but cooking can often add these.

7-9 servings of vegetables in a day. They may be fresh, frozen, canned, or juiced.

Fruit Group

In terms of food (rather than botany), fruits are the sweet-tasting seed-bearing parts of plants, or occasionally sweet parts of plants which do not bear seeds.

These include apples, oranges, plums, and bananas, etc. Fruits are low in calories and fat and are a source of natural sugars, fiber and vitamins. Processing fruits when canning or making into juices unfortunately this often adds sugars and removes nutrients; therefore fresh fruit or canned fruit packed in juice rather than syrup is recommended. The fruit food group is sometimes combined with the vegetable food group. It is best to consume 2-4 servings of fruit in a day. They may be fresh, frozen, canned, dried, pureed or juiced.

Note that many foods that are considered fruits in botany because they bear seeds are not considered fruits in cuisine because they lack the characteristic sweet taste.

Milk, Yogurt, and Cheese Group

Dairy products are produced from the milk of mammals, most usually but not exclusively cattle. They include milk and yogurt and cheese. Milk and its derivative products are a rich source of the mineral calcium, but also provide protein, phosphorus, vitamin A, and vitamin D. However, many dairy products are high in saturated fat and cholesterol compared to vegetables, fruits and whole grains, which is why skimmed products are available as an alternative. For adults, 3 cups of dairy products are recommended per day.

Meat, Poultry, Fish, Dry Beans, Eggs, and Nuts Group

Meat is the tissue - usually muscle - of an animal consumed by humans. Since most parts of many types of animals are edible, there is a vast variety of meats. Meat is a major source of protein, as well as iron, zinc, and vitamin B12 . Meats, poultry, and fish include beef, chicken, pork, salmon, tuna, and shrimp and eggs.

However, since many of the same nutrients found in meat can also be found in foods like eggs, dry beans, and nuts, such foods are typically placed in the same category as meats, as meat alternatives. These include tofu, products that resemble meat or fish but are made with soy, eggs, and cheeses. The meat group is one of the major compacted food groups in the food guide pyramid.

Although meats provide energy and nutrients, they are often high in fat and cholesterol, and can be high in sodium. Simply trimming off fatty tissue can go a long way towards reducing this negative effect. However, this tactic may prove to be ineffective, so large portions of meats are not recommended; 2-3 ounces per day of meat or alternatives are recommended. This is 3-5 servings. For those who don't (see Vegetarianism and Taboo food and drink) consume meat or animal products, meat analogues, tofu, beans, lentils, chick peas, nuts and other high-in-protein vegetables make up this food group.

Controversy

This 1992 food pyramid diagram can still be found on much of the food packaging in the United States

To many nutritional experts (eg Walter Wilett), the 1992 pyramid did not reflect the latest research on dietetics. Certain dietary choices that have been linked to heart disease, such as three cups of whole milk and an 8 oz. serving of hamburger daily, were technically permitted under the pyramid. The major points of criticism have been the pyramid's lack of differentiation within the protein-rich group ("Meat, Poultry, Fish, Dry Beans, Eggs, and Nuts"), some lack of clarity with regard to recommended serving sizes and the pyramid's lack of emphasis on whole grains. Some of the recommended quantities for the different types of food in the old pyramid have also come under criticism for lack of clarity. For instance, the pyramid recommends two to three servings from the protein-rich group, but this is intended to be a maximum. The pyramid recommends two to four fruit servings, but this is intended to be the minimum. Another problem is that the pyramid does not distinguish between whole grains and refined grains. Since some vegetarian diets tend to be based on refined grains, it can skew perceptions significantly.

The Harvard School of Public Health proposes the Healthy eating pyramid, which includes calcium and multi-vitamin supplements as well as moderate amounts of alcohol, as an alternative to the Food Guide Pyramid.

Vegan version of the nutritional food pyramid.

Many observers believe that the Harvard pyramid follows the results of nutrition studies published in peer reviewed scientific journals more closely. Some claim that the USDA was and is unduly influenced by political pressure exerted by food production associations. For instance, the recommended intake of 5 or more cups daily of fruits and vegetables is more than double the World Health Organization recommendation of 400g (about 0.9 lb.) and considerably greater than NHS recommendations.

See also

• 5 A Day
• Detox diet
• Health food
• Healthy diet