USANA Nutritionals

THE "AVERAGE DIET" THEORY

It would be nice to offer a solution to the problem of good nutrition by drawing up diets that would be right for everyone. Unfortunately, this is not as easy as it sounds, for several reasons.

First, foods mat are commonly found in one area of the country or in the diet of one ethnic or economic group may be uncommon in another. People's eating habits also vary widely, even within ethnic groups and regions of the country.

Second, a diet evaluation must include only food that is actually eaten. If considerations are based only on what is bought or prepared, the resulting nutritional picture will be distorted.

Third, the way you prepare and cook raw and processed foods at home may affect their vitamin content. For example, paring certain vegetables before cooking often results in the loss of most of their water-soluble vitamins. Baking and other cooking methods can also lead to vitamin loss.

When estimating the vitamin losses from your food during preparation, remember that it is unreasonable to expect that the preparation conditions of test foods will be identical to those being prepared in your home. Therefore, individual diets can be evaluated only by analyzing the final food product.

Fourth, your dietary or body level of one vitamin or mineral may influence your requirement for another. For example, many of the water-soluble vitamins' functions are interrelated because they all participate in the series of chemical reactions known as the Krebs cycle, which is involved in energy generation. Thus, a deficiency in one vitamin may affect the ability of the other vitamins to function. The nutrients that are interrelated in this way are niacin, thiamin, pyridoxine, riboflavin, biotin, pantothenic acid, choline, and cyanocobalamin.

Vitamin needs can also be related to the nature of your dietary intake. More thiamin, niacin, riboflavin, and other water-soluble vitamin requirements are needed in a high-carbohydrate diet. In contrast, a high-protein diet calls for increased pyridoxine and has an effect on the amount of riboflavin the body stores. Zinc seems to play a role in the action of vitamin A, so that vitamin A deficiencies can be more easily corrected if there is a sufficient amount of zinc in the diet And vitamin C (ascorbic acid) is a factor in the efficient absorption of iron from the gastrointestinal tract. Thus it is possible that you are taking enough iron but don't have enough ascorbic acid in the diet to get the full value of that iron. Usually, however, the situation is reversed, with more than enough C and too little iron in the diet.

Fifth, it is difficult and time consuming to translate information from nutrition value tables to our daily diet. For example, to determine the vitamin content of a simple ham sandwich on white bread, we must find the listing for "Ham: piece, approx. 4 1/8 in. long, 2 1/4 in. wide, 1/4 in. thick; wt 1 1/2 oz." Assuming that three such slices are used in our sandwich, we can determine that, from the ham alone, we will gain no vitamin A, 7.2 mg of niacin, 0.37 mg of riboflavin, 0.81 mg of thiamin, and no vita¬min C. Similar steps must be followed for every part of the sandwich, and then for total food intake.

Interestingly, the technology explosion has led to the introduction of a number of programs and services that will analyze your diet for vitamin and mineral content—as well as for fat, cholesterol, sodium, and other nutritive components—using a computerized listing of the information contained in the United Stales Department of Agriculture (USDA) tables on the nutritive value of American foods.

These computer programs can help you find an optimal diet by pointing out where your diet is lacking and making suggestions as to how to improve your eating patterns.

THE DIETARY GUIDELINES FOR AMERICANS

Over the years, nutrition and food researchers have developed a set of standard recommendations for the kinds of foods we should eat to maintain a healthy nutritional state.The Dietary Guidelines for Americans are the official policy of the United States Department of Agriculture and are updated every five years. The guidelines describe food choices that will help you meet the RDA/DRIs. They also intersect with the nutrition labeling that now appears on all packaged food products.

Here are the basic recommendations contained in the latest edition of the Dietary Guidelines for Americans:

• Eat a variety of foods. No one food can supply all of the vitamins, minerals, and other nutrients your body needs. By varying the foods you eat, you have the greatest chance of obtaining the full range of nutrients. The Food Guide Pyramid offers information on the number of servings and amounts of various foods that are most healthful to consume.

• Balance the food you eat with physical activity and maintain or improve your weight. Being overweight dramatically increases the risk for many diseases, such as high blood pressure, heart disease, stroke, diabetes, cancer, arthritis, and breathing disorders. Since many adults have a tendency to gain weight with age, this guideline encourages weight maintanance or loss as a goal of good health.

• Choose a diet with plenty of grain products, vegetables, and fruits. These foods are the basis of a varied and healthy diet. They contain vitamins, minerals, complex carbohydrates, and other compounds that are healthful, and they are usually low in fat.

• Choose a diet low in fat, saturated fat, and cholesterol. Although some dietary fat is needed to ensure good health, most Americans consume way too much fat and cholesterol. Such high-fat diets raise the risk of obesity, heart disease, and cancer.
 
• Choose a diet moderate in sugars. As with fat, Americans tend to go overboard with sugar, which is high in calories.

• Choose a diet moderate in sodium. Sodium has been associaed with high blood pressure. Sodium and sodium chloride (salt) are found in large amounts in processed and prepared foods.

• If you drink alcoholic beverages, do so in moderation. Alcohol is high in calories and typically devoid of nutrients and can cause a number of illnesses if consumed to excess. Moderation is defined as no more than one drink per day for women and two drinks a day for men.