Changing Nutritional Needs throughout Life
Age affects our nutritional needs. Sometimes the differences are obvious. It is easy to see the difference in the amount and types of food an infant, school-age child, teenager, and adult need. Other differences are more subtle. You may not realize that, as you get older, your calorie needs decrease, especially if you become less active. Being aware of such changes can help you to plan your meals more carefully, so you eat foods that provide plenty of nutrients for their calorie count.
If you have children, there are a number of things you should know about their nutritional needs. For example, doctors now recommend that infants breast-feed for the ﬁrst 12 months of their lives. Breast milk supplies better nutrition than commercial formula, promotes brain development, and provides infection-ﬁght- ing antibodies to help the infant stay healthy. Provide your partner with lots of support and encouragement while she breast-feeds your infant. Note that infants should not begin to drink cow’s milk until they are 1 year old because it can cause an allergic reaction and is too concentrated for an infant.
Toddlers and preschoolers sometimes become picky eaters as their newfound independence propels them into a variety of activities that seem much more interesting than eating. The best solution is to keep offering your young child a variety of foods while not forcing him or her to eat any one food in particular. A good rule of thumb to use when portioning out food is 1 tablespoon of food for every year of age, so, for example, a 3-year-old would get 3 tablespoons of each food at mealtime. Children under 2 years should not yet follow the Dietary Guidelines for Americans (see page 6) because they need fat in their diet for brain development.
As your child enters school, he or she will continue to need plenty of calories for proper growth, but be sure to encourage your child to engage in physical activity to balance his or her calorie intake. More and more American children are becoming overweight, a problem that can cause health problems such as obe- sity and diabetes in adulthood. Getting more exercise is generally a better solu- tion for an overweight child than dieting. Of course, you should limit high-calorie snacks. Encourage your child to snack on cut-up fruits and vegeta- bles such as apple slices and carrot sticks.
The rapid body changes that occur in adolescence are sustained by good nutri- tion. Teenage boys between ages 15 and 19 can require up to 4,000 calories per day. But many teenagers get most of their calories from fast food and junk food.
Even though your teenager may be more readily inﬂuenced by his or her friends than by you when it comes to food choices, you should do all you can to make nutritious food available in your home. Keep healthy snacks—cut-up vegetables, whole-grain crackers and pretzels, fresh fruit, cheese—in your kitchen. Resist the temptation to buy high-fat, high-calorie foods. Stress the importance of hav- ing a good breakfast (see page 7) to your teenage children.
Once you reach about 25 years of age, your nutritional needs stabilize and stay about the same until your senior years. Eating a low-fat, high-ﬁber diet that is rich in whole grains, vegetables, and fruits remains the most sensible dietary advice you can follow. The average man should consume about 2,500 calories per day—less if you are sedentary, and more if you are very active. Watch for weight gain as you age. Doctors no longer think that a moderate amount of weight gain is acceptable in the middle years of life (see the weight table on page
69). It is now known that any excess weight over the range recommended for your height is unhealthy and can increase your risk for common chronic health problems such as diabetes, high blood pressure, and heart disease. Regular exer- cise is an excellent way to help maintain a desirable weight at any age.
If you are very athletic, your calorie needs are higher than those of less active men. Athletes who compete in endurance events such as a marathon or a triathlon may require 5,000 calories per day or more. Some endurance athletes can become anemic because vigorous exercise causes a lower concentration of iron in the blood. Eating a balanced diet containing iron-rich foods such as beef, pork, the dark meat of poultry, dried beans, and enriched breads and cereals is usually enough to prevent sports anemia. Athletes do not need more protein than the average man, so protein supplements are usually unnecessary. Many runners practice “carbohydrate loading” before an event, believing that the extra carbo- hydrate intake will better fuel performance, but this popular practice is probably not helpful unless you are training at an extreme level.
The most important thing to remember when working out or competing in any athletic event is to drink enough ﬂuids. Water loss from breathing and perspira- tion can quickly dehydrate you, especially in hot or humid weather. It is critical to drink a lot of ﬂuids before exercising, about every 15 minutes during the workout, and for about 2 hours afterward. Water is the best thirst-quenching liq- uid, although sports drinks can replace the electrolytes (sodium, potassium, and other minerals) that you can lose during vigorous exercise in hot weather. How- ever, sports drinks also contain a lot of sugar.
As you get older, your metabolism (the chemical processes that take place in your body) slows down and your calorie needs drop. But you still require the same amount of vitamins and minerals. Eating healthfully can be difﬁcult when you are dealing with aging-related physical problems from chronic conditions such as arthritis, deteriorating eyesight, and gum disease. Emotional problems also can affect your diet. For example, depression, bereavement over the loss of a loved one, and loneliness can signiﬁcantly diminish your interest in cooking or eating. Also, living on a ﬁxed income often limits the type and the amount of food you can buy, and medications you are taking can sometimes affect your appetite. To make sure you continue to get all of the nutrients you need, take advantage of community programs for senior citizens. Ask your local senior cit- izens’ center whether they offer inexpensive meals. Talk to your doctor or a social worker at a local hospital to ﬁnd out what other kinds of programs, such as food stamps, home-delivered meals, or church-sponsored meal programs, are available in your community.