Puberty and Growth - Diet

It is no surprise that many American teenagers have poor eating habits. A survey by the Food and Nutrition Board of the National Research Council recently showed that 40 percent of boys between 13 and 19 years of age and 60 percent of the girls in the same age group subsisted on diets that were substandard. Generally, the young people surveyed had abandoned the healthy eating habits of their families. They habitually skipped breakfast and failed to make up the nutritional loss during other meals.

There are several reasons for this phenomenon. Perhaps the most prominent reason is that teens are anxious to break away from their home. They therefore rebel against any form of convention or parental advice. The popularity of fast food institutions and snack shops is a also great contributor to the problem. Such places have become frequent hang-outs for teenagers after school and on weekend evenings. With social gatherings in these surroundings, teenagers begin to develop poor eating habits. Frequently, they fill themselves up with non-nutritive foods and have no appetite later for balanced meals. At home, teenagers are great snack-eaters, and much snacking occurs while they are watching television. The combination of inactive television-watching and munching on junk foods leads to an unhealthy physical condition in teenagers.

Calories and Nutrition

A calorie is a unit of energy, and the human body requires a certain amount of energy each day in order to sustain life and continue normal physical activity. The amount of caloric intake varies according to the individual. Much of it depends on physical activity, size, and metabolic rate.

Calories in themselves are not bad. However, excessive intake of calories can lead to severe weight and health problems. Often the problem is not calories but the consumption of “empty calories” or non-nutritive foods. For instance, an unhealthy snack of a soda (100 calories) and French fries (roughly 450 calories) adds up to 550 “empty” calories. Conversely, a glass of skim milk (80 calories) and an apple (60 calories) is a healthy snack that adds up to only 140 calories.

To maintain the proper balance between foods consumed and energy used in work and play, a teenager must regulate his or her caloric intake. Much of the regulation occurs naturally. For example, when a person eats a lot, he or she is not hungry for a longer period of time than usual. Often, people crave foods that have been lacking in their diet. Thus, without conscious effort, most people are able to limit their consumption of foods to normal levels.

Nonetheless, it is important for teenagers to learn healthy eating habits and be aware of the potential of gaining weight. It is the awareness that is important for teenagers, not the strict regulation of body weight and caloric intake. Regularly checking one's weight on a scale is not a good idea. It will only foster unhealthy obsessions in teenagers who will worry about the loss or gain of a single pound. This can lead to skewed images of a teenager's physique and perhaps serious eating disorders. It is more important that a teenager monitor weight through the fit of his or her clothing.

Calcium and Phosphorus

Among the important minerals in teenage diets are calcium and phosphorus. Milk is the most easily available source of calcium and phosphorus, which are required for the development of strong bones during the period of life in which the body is still growing. Calcium also is required for the effective contraction of muscle tissues and is vital for normal heart function. The recommended daily intake of milk for teenagers is four eight-ounce glasses. It can be served as fluid whole milk, as skim milk, buttermilk, evaporated milk, or as nonfat dry milk. Cheese or ice cream can be substituted for part of the fluid milk allowance. One cup of ice cream is equivalent in calcium to one-half cup of milk. A one-inch cube of cheddar cheese is equal to two-thirds of a cup of milk, which also is equivalent in calcium to one cup, or eight ounces, of cottage cheese. Cream cheese can be substituted for milk in a two-to-one ratio; that is, two ounces of cream cheese are equal to one ounce of milk.

Iron

Iron is needed for the formation of hemoglobin , the substance that gives red blood cells their red coloration and is responsible for the transport of oxygen and carbon dioxide in the bloodstream. Hemoglobin has such an affinity for oxygen that without it humans would require 60 times as much blood to transport oxygen from the lungs to tissues throughout the body. Studies indicate that girls are five times as likely to need additional supplies of iron in their diets because of blood loss through menstruation. Recommended sources of iron are liver, heart, kidney, liver sausage, meat, shellfish, egg yolk, dark molasses, bread, beans and other legumes. If basic food lists seem drab and boring, the teenager might think of the iron sources in terms of a peanut butter sandwich or two hamburgers; either choice would provide the daily iron needs for a girl. Other minerals that are important to a teenager's diet include the following:

1. • Sulfur is needed by the body for hair, skin, nails, and cartilage, and is available by eating nearly any protein-rich foods.
2. • Iodine is needed for normal thyroid control of body metabolism and is supplied in the form of iodized table salt.
3. • Potassium is a tonic for the nervous system and the muscles and is available in adequate amounts in most kinds of meats, as well as bananas, orange juice, and milk.
4. • Magnesium collaborates chemically with calcium and phosphorus for normal muscle and nerve function, and is found in most forms of protein.

Note: Many of these nutrients are readily available in a normal diet. In most cases, it is not necessary to supplement a teenager's diet with these minerals. Children and teens should not rely on vitamin pills to make up for an unhealthy diet. It is better to eat nutritionally.

Weight Problems

Teens who are seriously overweight or who are contemplating radical weight reduction programs should be examined by a physician. Otherwise, unfair comparisons with other persons of the same age and height may lead to wrong conclusions about the need to gain or lose weight. The weight-height standards are based on averages, and there are many youngsters who are above or below the average but quite healthy and normal.

Another reason for a medical exam is to check the possibility of disease as the cause of the weight problem. The exam will also indicate whether the youngster has some other disorder that could be aggravated by a sudden weight loss.

Achieving optimum weight is only one step toward proper physical conditioning. A youngster who has been able to avoid physical activity by living in an elevator apartment, riding a bus to school, and watching TV after school hours instead of working or playing could be right on the button as far as weight for his age and height are concerned, but his muscular development and heart and lung capacity could be at the same time at a very low ebb.