Health & Fitness: Just for Teens -- When it comes to eating right to build a healthy body, teenagers' needs are unique (December 08, 2004)

By Monique Johnson

Special to the Almanac

Do you want to be healthy and strong, but you aren't sure where to start? Feeling overwhelmed by talk of low-carbs, low-fats, and trans fats?

The key is in getting back to the basics. The process of building a healthy body is in your hands, and it all starts with the food you eat every day.

But your needs are different from those of your parents, so don't' listen to all of the media hype. Your goal is to generate the energy you need to grow and be active, and to develop a fit body.

The first step in taking control is to educate yourself so you can make the right choices. We consulted two local experts -- Monica Holt, a registered dietitian with Lucile Packard Children's Hospital, and Darrin Freitas, sports nutritionist at the Riekes Center for Human Advancement in Menlo Park -- and they have offered the following guidelines just for teens:
What you need

Regular meals are important to fuel your body at a steady pace over the course of the day. You lead a busy life and skipping breakfast or lunch will only impair your ability to face your schedule.

Complex carbohydrates -- cereal, pasta, rice, and bread -- are an essential part of your diet. "They provide a wide variety of vitamins and minerals and are the prime source of energy for your active, growing body," explains Monica Holt. Whole-grain products are the best choice; they are fiber-rich, and hence your body breaks them down slowly for sustained energy. Approximately 40 to 60 percent of your daily food (about 6 servings) should come from complex carbohydrates; vary your intake of carbs within that range, depending on your level of activity.

Fruits and vegetables also supply important vitamins, minerals, anti-oxidants, and fiber. Make your plate of food as colorful as possible at every meal and you'll be on the right track. Try to get at least 5 servings of fruits and vegetables per day.

Protein provides amino acids, the body's building blocks that fuel growth and promote tissue repair to keep your body strong. You can get protein from animal, vegetable, and dairy sources. "Diversify your protein sources; try to get something from each of the three protein sources each day," Darrin Freitas says. But don't think that eating more protein will give you more muscles; only exercise increases muscle mass. About 10 to 20 percent of your food (or 2 to 3 servings) per day should be from protein sources.

Healthful fats are important to your body. Fats are vital components of cell membranes, help us absorb certain vitamins, are part of hormone production, and are the body's most efficient way of storing energy. Choose unsaturated fats -- these are liquid at room temperature -- such as olive oil, vegetable oils, and canola oil. Low-fat dairy products, nuts, avocados, and salad dressings fit in here. If you like fish, Ms. Holt recommends including cold-water fish in your diet as a good source of essential fatty acids (EFAs). Alternatively, flaxseed and flaxseed oil are excellent sources of EFAs. Up to 30 percent of your food should be healthful fats.

Hydration: Water is the largest component of your body. It is necessary to keep tissues active and to support all bodily functions. Bring a water bottle to school and drink water throughout the day. Getting enough fluid is especially crucial when you are participating in sports and other physical activities to keep your body functioning at peak performance.

Exercise is a fundamental part of a healthy lifestyle. It strengthens bones, helps your body produce hormones, boosts the flow of blood and nutrients in your body, and helps to burn off stress. The American Academy of Pediatrics counsels that all adolescents should be physically active as part of their daily routine and should also take part in moderate to vigorous exercise three or more times per week.

Calcium builds strong bones for now and for the rest of your life. Teens need approximately 1300 mg of calcium (or 4 servings) per day. Good sources of calcium are milk, yogurt, cheese, tofu, spinach, broccoli, and calcium-enriched juices. Don't avoid dairy products because you are afraid of fat. Choose low-fat dairy products to be sure you get the calcium you need.

Iron is a necessary component of hemoglobin, which carries oxygen to the body's tissues. You need more iron than an adult because muscle mass and blood volume are increasing as you grow. Teen-aged girls need 15 mg and boys need 12 mg per day. Iron is found in meat, fish, and poultry; iron-fortified breads and cereals; dark, green leafy vegetables; dried fruits; beans; and soy products like tofu and chick peas.
Things to watch out for

Simple sugars and simple carbohydrates , such as candy, soda and cookies, are called "empty calories" because they have little or no nutritional value and do not provide any long-term energy. "Though snacks like these may be OK during intense activity, these foods will put you on an energy rollercoaster, taking your energy up quickly and then quickly dropping it down hard," Mr. Freitas cautions.

Saturated fats are solid at room temperature and are the main evil behind cholesterol problems and heart disease. Examples are animal fats like butter and lard, chicken skin, and high-fat dairy products. Ms. Holt recommends that 10 percent or less of your daily diet come from these food sources.

High-fructose corn syrup is a top ingredient in a lot of "juices" sold today. You might think you're making a healthy choice, but you'll just be getting a lot of sugar in your drink. Look for 100 percent fruit juices instead -- or better yet, eat a piece of whole fruit, Ms. Holt suggests.

Caffeine is a mild stimulant of the central nervous system, promotes dehydration, and is addictive. You can get the jitters and sweats if you have too much. Coffee is not the only source; so-called "energy drinks" like RockStar, Red Bull, and Monster are loaded with hidden sources of caffeine. Mr. Freitas advises: "Be wary of loading up on caffeine, particularly during periods of exercise when you have an increased need for fluids. The resulting dehydration forces your heart to work much harder than normal and can be very dangerous."

Fast food equals lots of calories with very little redeeming qualities. Read "Fast Food Nation," by Eric Schlosser, and watch the documentary "Supersize Me," and you'll get all the information you ever wanted on fast foods.

Junk foods are often high in fat (total fat, saturated or trans fats). If these take up a large part of your diet, you may be putting yourself at risk for heart disease, diabetes, or obesity.

Fads and quick-fix solutions are all hype. Energy or nutrition in a can (powder or liquid), fad diets, and low-fat or low-carb products all promise miracle results that they cannot deliver. They are not designed for your growing body.
Coming up with a plan

Where do you go from here? Armed with the basics of healthy nutrition, you are ready for action.

How many calories (the measure of energy in food) do you need every day? First, as teenagers, you need more calories than adults because more energy is needed to fuel the growth and changes your bodies are experiencing.

Secondly, individual caloric needs depend on your size and build, growth rate, and level of physical activity. Ms. Holt and Mr. Freitas recommend that you estimate your daily needs by using the Caloric Needs Calculator at www.active.com/calculator.

Next, figure out a healthy weight range for your growing body by calculating your Body Mass Index (BMI), a measure of body fat based on height and weight. Unlike adults, a child's or teen's BMI must also take into account your age and sex. Visit http://features.todaysparent.com/fat_action/bmi/bmi_children.htm for a straightforward approach to using BMI.

Now it's time to get your parents involved; they need to be educated as well. The "Family Plan for Healthful Eating" (on Page XX ) offers them some tips to support your goals.

Remember, the critical components of a healthy lifestyle are knowledge, whole foods, and exercise. Start slowly and build to a healthy eating pattern for life.

Monique Johnson is a Menlo Park freelance writer and the mother of three boys, including two growing teenagers.
Healthy snack choices for teens

Running from class to after-school activities? Looking for something healthful to stash in your backpack or lunch bag? Need a boost between studying and socializing? The foods below are healthy choices, recommended by dietitian Monica Holt and sports nutritionist Darrin Freitas, to keep you going. ** Whole-grain bagel with peanut butter ** Cottage cheese ** Sliced lean deli meats on whole-grain bread (turkey, ham) ** Dried fruit, such as raisins, dried cranberries, dried apricots, etc. ** Fresh fruit and veggies (cucumber or carrot sticks, celery with peanut butter) ** Popcorn ** Low-fat yogurt or yogurt drinks (mix in granola for extra punch) ** Nuts ** Whole-wheat crackers and cheese ** Frozen fruit bars ** Rice cakes ** Baked corn chips with salsa or guacamole ** Trail mix -- nuts, dried fruit, granola, seeds mixed together ** Fruit smoothie -- frozen fruit, yogurt or silken tofu, 100 percent fruit juice ** Low-fat cheese ** Pita triangles with hummus ** Graham crackers ** English muffin pizza ** Peanut butter and jelly on whole-wheat bread ** Oatmeal ** Soup ** Burrito ** Soybeans; edamame

Further reading

Looking for more information? Here's what our experts recommend:
Web sites

** www.eatright.org -- Official site of the American Dietetic Association. Valuable information, recommended books, and a link to find a nutrition professional in your area. ** www.foodwatch.com.au -- A comprehensive site for straightforward nutrition information set up by a leading Australian nutritionist. ** www.FitDay.com -- A simple way for your family to track nutrition and health goals.
Newsletters

** The Berkeley Wellness Letter (UC Berkeley School of Public Health) www.wellnessletter.com ** The Tufts Health and Nutrition (Tufts University School of Nutrition), www.healthletter.tufts.edu ** Nutrition Action Health Letter (Center for Science in the Public Interest) www.cspinet.org
Books

Both available through the Peninsula Library System ** American Academy of Pediatrics Guide to Your Child's Nutrition, edited by Dr. William Dietz and Dr. Loraine Stern, c. 1999 by Villard Books, New York. ** "Fueling the Teen Machine," by Ellen Shanley and Colleen Thompson, c. 2001 by Bull Publishing, Palo Alto, California.

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