Teen nutrition

Teen nutrition
Teen nutrition

Teen nutrition involves making sure that teens eat healthy foods to help them grow and develop normally, as well as to prevent obesity and future disease. Following dietary guidelines recommended by research and medical professionals supports proper nutrition.

The guidelines include selections from different food groups to provide the vitamins and minerals teens need as they grow through puberty and into adulthood. The U.S. Department of Agriculture’s (USDA) Food Guide Pyramid recommends how many servings a day an adolescent should eat of each food group, such as milk, vegetables, fruits, fats, and meats.

By sticking closely to the guidelines, parents can ensure their teens get a well-balanced diet that supplies the vitamins and calories they need to stay healthy and support growing bodies and active lifestyles.


Origins

Humans, unlike plants, cannot manufacture the nutrients they need to function. Each culture over centuries has developed its own traditional diet. In Western civilization, many of these diets have developed into convenient, fatty and sugary foods, leading to obesity even in children and teens.

Advice on nutritional choices predates recorded language, but the first science-based approach to a healthy diet probably began just over 100 years ago. W. O. Atwater, the first director of the Office of Experiment Stations in the USDA and a pioneer in the field of nutrition investigation, developed some of the components needed for a food guide. He created food tables with data on protein, fat, carbohydrate, mineral matter, and fuel value for common foods.

Food guides with food groups similar to those used today first appeared in USDA publications in 1916 and were developed by the nutrition specialist Caroline L. Hunt.

The first daily food guide was published under the title Food for Young Children. In the early 1930s, the Depression caused economic restraints on families and the USDA responded with advice on how to select healthy foods more cheaply.

In 1941, the Food and Nutrition Board of the National Academy of Sciences released the first recommended dietary allowances (RDAs) for calories and essential nutrients. The nine nutrients included on the list were protein, iron, calcium, vitamins A, C, and D, thiamin, riboflavin, and niacin.

Throughout the years following the release of the first guidelines, recommendations were debated and revised. The new food guide was first presented in 1984 as a food wheel.

Food pyramid
Food pyramid

The USDA first used a pyramid to represent the food groups in 1992 after intensive research on the most effective way to visually communicate healthy eating by portion and food choice. Although it has been modified over the years, the pyramid has continued to represent the food groups. A new revision of the guide-lines has been planned for 2005.

Benefits

The Food Guide Pyramid and other healthy eating recommendations generally apply to children age two and older. When used as a starting point for planning family meals and snacks, applying these sensible recommendations to teenagers’ daily diets can encourage good eating habits before adulthood. This will help teens develop mentally and physically and prevent obesity or eating disorders.

Many nutritional experts agree that if teens eat a balanced diet that includes all of the recommended food groups, they will not need to take any vitamin supplements. Eating a balanced diet with a variety of foods will give teens the energy they need to stay physically active—which is important to their growth, mental health, and to keeping obesity in check.

Description

In spite of recommendations, the quality of most teens’ food intake is not what it should be. Today, about nine million U.S. children ages six to 19 are overweight.

The number of teens age 12 to 19 with weight problems has tripled since the 1980s. Body mass index (BMI) is a measurement system used to assess if a child (or adult) is underweight, overweight, or at risk for becoming overweight.

Pediatricians use height and weight measurements taken at a child’s regular checkups to determine his or her BMI. Anyone who weighs more than 85% of teens the same height, age, and sex is considered overweight. The Centers for Disease Control (CDC) considers anyone in the 95th percentile obese.

To help guide teens, their families, schools, and others in making healthy nutritional choices, the USDA guidelines suggest the following daily food selections:
  • Six to 11 servings of breads, cereals, rice, and pasta
  • Three to five servings of vegetables
  • Two to four servings of fruit
  • Two to three servings of dairy products
  • Two or three servings of meat, fish, poultry, and legumes
servings per day
servings per day

Fats, oils, and sweets are at the top of the pyramid, but are not considered an actual food group. They occur in many foods from other groups and should be used only sparingly. The USDA says only about 30% of daily calories should come from fat.

Calcium requirements are particularly important for teens, yet studies show that about 60% of teenage boys and more than 85% of teenage girls fail to get the recommended daily allowance of calcium.

Calcium not only helps strengthen bones and make for healthier teeth, it also is important in the teen years to prevent future osteoporosis, a painful condition that causes weakened, less dense bones in later adult years. Teens should consume 1,200–1,500 mg of calcium per day.

Some excellent sources of calcium include:
  • lowfat milk: 300 mg per cup
  • white beans: 115 mg per 0.5 cup
  • lowfat yogurt: 300 mg per 8 oz
  • orange: 40–50 mg per medium-sized orange

Iron requirements are also very important for adolescent health and growth. Teens need 12–15 mg of iron per day. A variety of iron sources come from each food group.

Some include:
  • peanut butter
  • whole grain bread
  • spinach
  • green beans and lima beans
  • beef, poultry, or fish
  • strawberries

For both calcium and iron, female teens need the higher recommended amount per day in order to build strong bone and muscle that will prevent against osteoporosis and other conditions associated with post-menopausal women. Teen males need at least the minimum requirement.

Preparations

Getting teenagers to eat the right foods is easier if they have begun good eating habits at a young age and if they are offered a variety of healthy foods. Many books, magazines, and web sites offer tips on making healthy foods interesting. Many of these resources are geared to teens and include recipes.

Some selections for each food group include:
  • Breads, cereals, and pastas include whole grain breads, bagels, unsweetened cereals, rice, whole grain crackers, cornbread, English muffins, and rice cakes.
  • Vegetable servings can come from cooked or raw vegetables such as asparagus, beets, broccoli, carrots, corn, green and red peppers, green beans, kale, peas, pumpkin, squash, sweet potato, tomato, zucchini, or vegetable juice.
  • Good fruit choices include such whole fruits as apples, applesauce, bananas, cantaloupe, apricots, peaches, fruit cocktail, plums, grapefruit, kiwi, nectarines, strawberries, and watermelon.
  • In addition to milk, lowfat yogurts and cheeses are good dairy sources, as are lowfat cottage cheese, custard, ice milk, and occasional ice cream servings.
  • Meat, fish, poultry, and legumes choices include lean meats, dried beans, peanut butter, shellfish, dried peas, lentils, and tofu.

To reduce fat in a teen’s diet, parents and their teenage children can switch to low-fat or nonfat milk, remove skin from poultry or trim fat from red meat, reduce use of margarine and butter, use lowfat cooking methods such as baking, broiling, and steaming, and serve foods rich in fiber.

Fresh salads can improve fiber in diet, as can adding oat or wheat bran to baked foods. Milk, cheeses, tofu, and salmon are good sources of calcium. Fruit smoothies are good replacements for milk shakes.

It is important that teens eat three meals a day and not skip breakfast. Studies have shown that children and teens that skip breakfast have more trouble concentrating and do not perform as well in school. Skipping breakfast in childhood and adolescence also is related to later health problems such as obesity and heart disease.

While the obesity problem in today’s youth can be blamed on a number of factors, including larger food portions for adults and children, convenient salty snack foods, and cheap and convenient fast food, much attention has been focused on the nation’s schools.

There are fewer physical education classes because of more emphasis on academic classes. Those gym classes that remain have too much standing around and not enough activities that interest the students, say some experts.

School lunches generally offer balanced nutrition, but many schools also offer “snack bars” or vending machines that dispense sodas and sugary, fatty, or salty snacks. Many teens have been choosing these snacks over the prepared school lunches.

To counter the problem in schools, the Healthy Schools Summit was held in October 2002. It consisted of representatives from more than 30 national education, fitness, nutrition, and health organizations, as well as 450 school administrators, government leaders, food service directors, counselors, dietitians, nurses, and health and fitness teachers.

Since that time, many school districts around the country have been working to improve their physical education programs and to remove or change the selections offered in vending machines and snack bars on school campuses. Educating teens and helping them choose healthy alternatives from home, school, or away from campus can help solve the problem as well.

At home, parents also choose convenient snack and fast foods because, both parents often work long hours. Along with bigger portions and increased time spent in front of the television instead of out being physically active, today’s youth are becoming obese.

They are receiving and growing accustomed to less nutritional food choices. Many experts say that getting teens up off the couch and stocking healthy snack choices helps.

Also, many sources can help parents find healthier alternatives to fast food meals for their families. Suggestions include cooking meals on weekends and freezing them for busy weekdays, and looking for cookbooks or online sources of quick and healthy recipes.

Simply cooking with less fat by using cooking sprays and baking, roasting, or poaching methods instead of frying helps teens and adults. Also, offering teens healthy snacks to last them until mealtime will keep them from reaching for poor snack choices and make them less likely to overeat at the evening meal.

Teens who are very active and participate in organized sports need a particularly healthy diet. Many teens hear of ideas such as loading up on carbohydrates or proteins to train for sports, often the night before a competition.

In reality, the best training is to stick to the Food Pyramid, say nutrition experts. Athletic teens may eat extra helpings of complex carbohydrates, such as whole grain rice, pasta, bread, and cereal.

Some extra protein is good to help build strong muscles, but eating too much of just one food group rather than a balanced diet is not recommended for athletes or anyone else. An active male teen needs approximately 2,800 calories per day. They should eat the higher suggested number of servings in each food group.

Active female teens require 2,200 calories per day. They should eat the average number of suggested servings per food group. Teens that are not as active and are overweight should eat the lower number of suggested servings per food group and cut back on their daily ingestion of fats, oils, and sugars.

While all teens need to drink plenty of water, those who participate in sports need to drink even more. Some experts say an easy formula to remember is one cup of fluid for every one-half hour of physical activity.

Another telltale sign of thirst is the color of a teen’s urine. If a teen’s urine is clear or the color of pale lemonade, he/she is drinking enough fluids. Dark urine the color of apple juice indicates too little hydration and the teen is in danger of dehydration or heatstroke.

For a variety of reasons, some teenagers follow vegetarian diets. Some people are concerned that a vegetarian diet is harmful for children and teens, but generally, if the teen still follows the recommended Food Guide Pyramid and makes good food choices, a vegetarian diet can be healthy.

About 2% of children ages six to 17 never eat meat, fish, or poultry. A survey in early 2003 found that vegetarian adolescents drank fewer sodas and ate less fast food than non-vegetarian teens.

Vegetarian teens may need vitamin supplements to make up for some of the vitamins normally obtained in meats or meat products; a physician or professional nutritionist can help determine the proper level of supplement needed.

Precautions

Many teens and their parents have been cautioned not to turn to fad diets for teenage weight problems. Many of the diets and diet products on the market have not been proven by clinical studies as effective in the long term for adults; they certainly have not been proven safe or effective as a solution to weight problems in children and teens.

Often, teenagers are more susceptible to claims made about diet plans and parents should help them research these diets or to speak with a physician or other licensed practitioner to determine their effectiveness.

The best solution for obesity is a combination of activity, a balanced diet that follows the USDA guidelines for food groups and portions, and involvement of a physician, dietitian, or other trained professional as needed.

Further, adolescents who worry too much about weight and appearance can develop social anxieties and eating disorders such as anorexia and bulimia. Over one third of American teenaged females have used such unhealthy methods as self-induced vomiting, laxative abuse, diet pills, and water pills to control their weight.

Eating disorders

This is how eating disorder begins
This is how eating disorder begins

Anorexia usually occurs in teenage girls and young women who have a greater than normal fear of being fat. People with anorexia hardly eat at all, and they obsess over the food they do eat. A teenage girl with anorexia might weigh every bit of food she eats, compulsively count all calories, or exercise to the extreme to work off calories she has consumed.

The difference between anorexia and normal dieting is the obsession with weight loss and the desire to go beyond being fit and trim to being as thin as possible, no matter the cost. Warning signs for anorexia are a weight drop to abut 20% below normal, a teen who denies feeling hungry, excessive exercise, feeling fat, and withdrawal from social activities.

Teens with bulimia binge on food for a few hours, then get rid of it quickly by vomiting or taking laxatives. This binge and purge behavior is more difficult to spot than anorexia, because the teenager may be of average weight.

The warning signs for bulimia include frequent excuses to go to the restroom immediately after meals, eating huge amounts of food without gaining weight, and using laxatives or diuretics.

Side effects

Only the fat-soluble (capable of being dissolved in fat or oil) vitamins A, D, K and E have side effects that are potentially, though rarely, toxic (poisonous).

In their book The Real Vitamin & Mineral Book, Sheri Lieberman and Nancy Bruning state, “The facts are that only a few vitamins and minerals have any known toxicities, all of which are reversible, with the exception of vitamin D.

Anything can be harmful if you take enough of it—even pure water. But vitamins and minerals are among the safest substances on earth. The amounts needed to become toxic are enormous.”

They add that being on medication or having a medical condition can influence vitamin/mineral requirements and indicate that when one’s physician is not well-versed in nutrition, it is ideal to have him work with a qualified nutritionist.

With regard to vitamin D, they indicate, “According to several studies, up to 1,000 IU per day of vitamin D appears to be safe. Both the beneficial and adverse effects of exceeding this amount are controversial. Over-dosing of vitamin D is irreversible and may be fatal.

Symptoms of too much vitamin D are nausea, loss of appetite, headache, diarrhea, fatigue, restlessness, and calcification of the soft tissues (insoluble lime salts in tissue) of the lungs and the kidneys, as well as the bones.” Vitamin D (400 IU) is usually sold with vitamin A (5,000 IU) in a tiny tablet or capsule.

Lieberman and Bruning say that active vitamin A from fish liver oil or synthetic palmitate is stored in the liver; that 15,000 IU would cause problems in infants; but that 100,000 IU of active vitamin A would have to be taken daily for months before any signs of toxicity (state of being poisonous) appear. Vitamin A in the form of beta-carotene can be taken without any risk of toxicity.

At doses of 800–1,200 IU per day, Lieberman/Bruning found no well-documented toxicity of vitamin E. At doses of over 1,200 IU per day, adverse effects such as flatulence, diarrhea, nausea, headache, heart palpitations, and fainting have been reported, but were completely reversible when dosage was reduced.

Vitamin K is easily obtained by the body from a healthy diet and deficiencies are rare, especially in children.

It is given prophylactically to newborn infants to prevent hemorrhage and before surgery to people with blood-clotting problems. Lieberman/Bruning describe the major effect of too much vitamin K as an anemia where red blood cells die more quickly than usual and cannot be replaced by the body.

Eating disorders

If a teen weighs less than 15% of the normal weight for his/her height, he/she may not have enough body fat to keep vital organs functioning. When a person is undernourished the body slows down as if it is starving and blood pressure, pulse rate, and breathing slow. Girls with anorexia often stop menstruating.

Anorexics can also experience lack energy and concentration, as well as light-headedness. They become anemic, their bones can become brittle, and they can damage their heart, liver, and kidneys. In the most severe cases, they can suffer malnutrition or even death.

The repeated vomiting of bulimia causes constant stomach pain. It also can damage the stomach and kidneys. Acids from the stomach that come up into the mouth when vomiting can cause tooth decay.

Teenage girls with bulimia also may stop having menstrual cycles. Constant vomiting may also cause bulimics to lose too much of a mineral called potassium, which can lead to heart problems and even death.

Research and general acceptance

The American Medical Association (AMA) has based many of its food choices on the Dietary Guidelines for Americans, which were developed through research by the U.S. Department of Agriculture and the U.S. Department of Human Services. Input for the guidelines comes from a number of resources, including national surveys from the Centers for Disease Control (CDC).

As for teens, accepting the importance of nutrition is another story. A 2000 report from the CDC showed that many teens know the basics of healthy eating but few actually follow the recommendations. They simply prefer unhealthy foods most of the time.

In focus groups, some teens in the eighth and ninth grades said they would eat healthy foods right before participating in a sport, but most thought their current behaviors could not affect their health at this time in their lives.