Questions and Answers

MOST of the questions that are answered here were asked of home demonstration agents by people all over the United States.

They indicate the widespread interest of Americans in nutrition and the kinds of information they want. The questions are barometers, in a sense, and guides that are useful in a number of projects.

Not all the questions fitted into the purpose of this book. Many others are considered at length in the chapters that follow. Some questions from various sources were added to round out this section and reflect more fully the scope of the book--although all the questions and answers together do not form a summary.

How old is man's knowledge of nutrition?

As early as 1900 B.C., Egyptians recognized that diet might be a factor in the development of night blindness and related eye symptoms. For these, raw liver, which we now know is rich in vitamin A, was recommended as a curative procedure.

In 525 B.C., Herodotus recorded that in an examination of Persian and Greek skulls it appeared that the bone structure of the Greeks was considerably stronger, perhaps as related to differences in exposure to sunlight. We now know the importance of vitamin D in bone development and the effectiveness of sunlight in promoting vitamin D activity in the body.

The fascinating sequence of ideas in nutrition investigations has been related by Dr. Elmer V. McCollum, a pioneer investigator himself, in his comprehensive book, A History of Nutrition (Houghton Mifflin Company, 1957). Dr. McCollum suggested that Cato the Censor, the grim Roman statesman of the first century B.C., was perhaps the earliest effective teacher of sound dietetics because of his discourse on the value of cabbage, currently recognized as a relatively good source of the essential nutrient, vitamin C, as a restorer and preserver of health in times when dried or cooked cereals, lacking in vitamin C, were subsistence items among the populations.

Biblical references to the effects of certain foods or variations in food supplies, both feast and famine, are numerous. Similar observations through the Middle Ages have been recorded.

Dr. McCollum reviewed reports from throughout the world during the 17th, 18th, and 19th centuries that describe extensive epidemics, which we now recognize included symptoms of nutritional deficiency diseases, such as rickets, scurvy, pellagra, the neurological symptoms of beriberi, night blindness, anemia, and goiter.

What's a good way to lose weight?

Here are a few simple rules to follow in choosing low-calorie meals:

Select a varied diet that contains the different kinds of foods important for health milk, meat (or alternates), fruit and vegetables, and whole-grain or enriched or restored cereals and bread.

Choose the foods with fewer calories in each of these groups. For instance, skim milk and buttermilk provide fewer calories than whole milk.

Prepare and serve foods in ways that do not add calories. Avoid fried foods, rich sauces, gravies, salad dressings, rich desserts, and so forth.

Reduce the amount of food eaten. Take smaller servings.

Avoid snacking and between-meal eating unless such foods are planned as part of the total allowance of calories.

Take some exercise regularly to increase your expenditure of calories and to keep the body physically fit.

How do I know if I am getting enough calories?

Your weight is a good guide to whether you are getting enough calories. An adult should eat enough to maintain the weight that is desirable for him. Usually your weight at 25 to 30 years of age is considered your desirable weight for the rest of your life. If you weigh more than this amount, you probably are getting too many calories. If your weight is below this standard, you may need more calories. The child and teenager, who are still growing, need enough food to permit normal gains in weight.

How many calories are there in a plain gelatin dessert? Why do some doctors recommend it?

One-half cup of ready-to-serve gelatin dessert, eaten plain with no fruit added, furnishes about 80 Calories and about 2 grams of protein.

Doctors may recommend this food because it is easily digested, bland in flavor, and is acceptable to most people. It may be used in calorie-restricted diets as a substitute for desserts of higher calories.

Can vegetable protein be substituted equally for animal protein?

Vegetable proteins generally are of lower quality than animal proteins because they fail to provide the complete assortment of amino acids in the amounts the body needs for tissue building. Certain foods of plant origin soybeans, nuts, dry beans, and peas are better than others from plants. It takes only a small amount of protein from animal sources, however, to supplement the protein in vegetable foods. Combinations like cereal and milk, macaroni and cheese, egg and bread, and beans and frankfurters provide better protein than foods of plant origin used alone.

Is bread that is advertised as high protein bread a good substitute for meat?

No. Many of the breads advertised as "high-protein" bread contain very little more protein than ordinary bread. Four slices of the ordinary white bread contain less than half as much protein as in an average serving of lean meat ( 2 to 3 ounces cooked). The protein in bread must be combined with some protein from foods of animal origin in order to provide all of the amino acids needed by the body.

What can we eat to give us protein and few calories?

Good sources of protein that are relatively low in fat and thus in calories are skim milk, cottage cheese, eggs, lean meat and fish, chicken, and turkey.

What foods, if any, enhance fertility in women and virility in men?

There is no food that enhances fertility in women and virility in men. Foods contribute nutrients that are important to good health, and the overall state of health may affect fertility and virility.

What is inositol? What is its value?

Inositol is included often among the vitamins of the B complex. It is required for the growth and proper nutrition of animals, but its role in human nutrition is not yet known.

My child likes candy very much. How much should I give him?

Be sure he is eating all of the foods he needs for growth and health before giving him candy. Then be sure that the candy does not add more calories than he needs.

How does the protein content of peanut butter compare with that of meat?

Four tablespoons of peanut butter supply about the same amount of protein as 2 ounces of lean cooked meat (without bone).

Is fat essential in my diet?

Yes; some fat is necessary for good nutrition. Fat is a concentrated source of calories. Some fats provide vitamins A and D, and some are important as sources of essential fatty acids.

What is lecithin? What is its value in nutrition?

Lecithin occurs in various animal and vegetable tissues. It is chemically related to the fats. Lecithin is added to many foods because it has unusual properties, such as those of retarding oxidation, retaining moisture, and dispersing globules of fat.

What is glutamic acid?

Glutamic acid is one of the simple amino acids. It does not have to be provided as such in our diets because the human body can make it from other amino acids provided by our food.

What is wheat germ?

Wheat germ is the portion of the kernel called the embryo, from which the new plant starts its growth. It is about 2 to 3 percent of the kernel. The germ is a concentrated source of protein, iron, vitamin E, and the B vitamins. Its nutritional contribution to the ordinary diet is limited, however, because of the small amounts generally eaten, alone or combined with other foods.

How much vitamin E is required?

Little is known about the human requirement for this vitamin. Vitamin E is so widely distributed in common foods that there is little likelihood of a dietary deficiency. Wheat germ oil is the richest natural source of vitamin E, but the vitamin is present also in other vegetable and seed oils, green leaves, meat, eggs, and dairy products.

Which foods are especially important for sound teeth in children?

A diet adequate in all nutrients is necessary for the formation and maintenance of good teeth.

What is the value of brewer's yeast?

Brewer's yeast is a concentrated source of high-quality protein and of many of the B vitamins. Because it is also a good source of the minerals iron and phosphorus, it sometimes is prescribed for patients needing dietary supplements.

What is "royal jelly"? Has it any value in nutrition?

"Royal jelly" is a substance from the salivary glands of bees and fed by the worker bees to the queen bee. No important nutrient has been reported to be present in "royal jelly" that cannot be obtained readily from ordinary foods in our regular food supplies. Some food faddists claim that "royal jelly" has special health values for human beings, but there is no scientific basis for such claims.

Is it safe to cook acid foods in aluminum?

Yes. There is no scientific evidence to prove that cooking acid foods in aluminum pans is harmful.

Does beer furnish any nutrients?

Beer furnishes calories and very small amounts of some nutrients. The amounts of minerals and vitamins present are too small to be important in an ordinary diet.

Are carbonated beverages good for children?

The nutritive value of carbonated beverages is mainly in their sugar and calories. Children's diets may be deficient in essential nutrients if carbonated beverages are used in place of nutritionally important foods.

What is the difference in the nutritive values of ice cream and sherbet?

Ice cream is prepared largely from milk products and sweetening agents and contains the nutrients contributed by these foods. Sherbet is made with fruit or fruit juices, sweetening ingredients, and usually small amounts of milk or egg white.