Unit 11 — Lifespan Nutrition
Puberty marks the beginning of adolescence, the time between childhood and young adulthood. The DRI recommendations divide adolescence into two age groups: 9 through 13 years, and 14 through 18 years. The onset of puberty brings a number of changes, including the development of the reproductive organs, the onset of menstruation in females, growth spurts, and changing body composition. Fat usually assumes a larger percentage of change in body weight in girls, while teenage boys experience greater muscle and bone development. All of these changes should be supported with sound nutrition.
Adequate energy intake is necessary to support the dramatic growth that takes place during adolescence. For ages 9 to 13, girls should consume about 1,400 to 2,200 calories per day, and boys should consume 1,600 to 2,600 calories per day. For ages 14 to 18, girls should consume about 1,800 to 2,400 calories per day, and boys should consume about 2,000 to 3,200 calories per day. Calorie needs vary based on activity level. The extra energy required for physical development during the teenage years should be obtained primarily from nutrient-dense foods instead of empty-calorie foods, to support adequate nutrient intake and a healthy body weight.
For children and adolescents ages 4 through 18, the AMDR for carbohydrates is 45 to 65 percent of daily calories, and most of these calories should come from high-fiber foods such as whole grains. The AMDR for protein is 10 to 30 percent of daily calories, and lean proteins, such as meat, poultry, fish, beans, nuts, and seeds are excellent ways to meet protein needs. The AMDR for fat is 25 to 35 percent of daily calories. The focus should be on unsaturated plant fats to prevent chronic diseases.
Micronutrient recommendations for adolescents are mostly the same as for adults, though children this age need more of certain minerals. The most important micronutrients for adolescents are calcium, vitamin D, vitamin A, and iron.
- Calcium levels increase to 1,300 mg/day during adolescence to support bone growth and prevent osteoporosis later in life. Low-fat dairy products and foods fortified with calcium, such as breakfast cereals and orange juice, are excellent sources of calcium.
- Iron needs increase for adolescent girls with the onset of menstruation (15 mg/day for ages 9 to 13 and 18 mg/day for ages 14 to 18). Adolescent boys also need additional iron for the development of lean body mass (11 mg/day for ages 14-18).
- Vitamin A is critical to support the rapid development and growth that happens during adolescence. Adequate fruit and vegetable intake meets vitamin A needs.
Eating disorders involve extreme behaviors related to food and exercise. They encompass a group of conditions marked by under-eating or overeating, as discussed in Unit 7. Eating disorders stem from stress, low self-esteem, and other psychological and emotional issues. They are most prevalent among adolescent girls but have been increasing among adolescent boys in recent years. Because eating disorders often lead to malnourishment, adolescents with eating disorders are deprived of the crucial nutrients their still-growing bodies need. Girls with anorexia experience nutritional and hormonal problems that negatively influence peak bone density, and therefore may be at increased risk for osteoporosis and fracture throughout life.1 It is important for parents to watch for signs and symptoms of these disorders, including sudden weight loss, lethargy, vomiting after meals, and the use of appetite suppressants. Eating disorders can lead to serious complications or even be fatal if left untreated. Treatment includes cognitive, behavioral, and nutritional therapy.
Children need adequate caloric intake for growth, and it is important not to impose very restrictive diets. However, exceeding caloric requirements on a regular basis can lead to childhood obesity, which has become a major problem worldwide. According to the CDC National Center for Health Statistics, the prevalence of obesity was 18.4% for youth ages 6 to11 and 20.6% for youth ages 12 to 19 in 2106.2
There are a number of factors that may contribute to this problem, including:
- early life factors, such as lack of breastfeeding support
- larger portion sizes
- limited access to nutrient-rich foods
- increased access to fast foods and vending machines
- declining physical education programs in schools
- insufficient physical activity and a sedentary lifestyle
- media messages encouraging the consumption of unhealthy foods
Children who suffer from obesity are more likely to become overweight or obese adults. Obesity has a profound effect on self-esteem, energy, and activity level. Even more importantly, it is a major risk factor for a number of diseases later in life, including cardiovascular disease, Type 2 diabetes, stroke, hypertension, and certain cancers.3
One major contributing factor to childhood obesity is the consumption of added sugars, especially in the form of sugar sweetened beverages.4 Added sugars include not only sugar added to food at the table, but also ingredients in items such as bread, cookies, cakes, pies, jams, and soft drinks. In addition, sugars are often “hidden” in items added to foods after they’re prepared, such as ketchup, salad dressing, and other condiments. According to the National Center for Health Statistics, young children and adolescents consume an average of 362 calories per day from added sugars, or about 16% of daily calories, 10% more than what the Dietary Guidelines for Americans recommends.5 Adolescent boys (ages 12 to19 years) have the greatest intake of added sugar, averaging 442 calories. The primary offenders are processed and packaged foods, along with soda and other beverages. These foods are not only high in sugar, they are also light in terms of nutrients and often take the place of healthier options.
If a child gains weight inappropriate to growth, parents and caregivers should nurture eating competence and follow the division of responsibility as previously discussed in this unit. In addition, it is extremely beneficial to increase a child’s physical activity and limit sedentary activities, such as watching television, playing video games, or surfing the Internet. Programs to address childhood obesity can include behavior modification, exercise counseling, psychological support or therapy, family counseling, and family meal-planning advice. For most, the goal is not weight loss, but rather allowing height to catch up with weight as the child continues to grow. Rapid weight loss is not recommended for preteens or younger children due to the risk of deficiencies and stunted growth.
One of the psychological and emotional changes that takes place during this life stage includes the desire for independence as adolescents develop individual identities apart from their families. One way that teenagers assert their independence is by choosing what to eat. They have their own money to purchase food and tend to eat more meals away from home. Too many poor choices can make young people nutritionally vulnerable.
At this life stage, young people still need the structure of family meals. Evidence shows that eating family meals is associated with nutritional benefits, including eating a diet with more fruits, vegetables, fiber, and micronutrients, and less fried food, soda, and saturated and trans fat.6
- Lane Community College’s Nutrition: Science and Everyday Application “Classification of Nutrients ” CC BY-NC 4.0
- University of Hawai‘i at Mānoa Food Science and Human Nutrition Program. (2018). Adolescence and Late Adolescence. Human Nutrition. http://pressbooks.oer.hawaii.edu/humannutrition/
- 1National Institute of Health: Osteoporosis and Related Bone Diseases National Resource Center. (2018). What People With Anorexia Nervosa Need To Know About Osteoporosis. Retrieved from https://www.bones.nih.gov/health-info/bone/osteoporosis/conditions-behaviors/anorexia-nervosa
- 2Hales, C.M., Carroll, M.D., Fryar, C.D., Ogden, C.L. (2017). Prevalence of Obesity Among Adults and Youth: United States, 2015–2016. National Center for Health Statistics. NCHS Data Brief, No. 288. Retrieved from https://www.cdc.gov/nchs/data/databriefs/db288.pdf
- 3World Health Organization. (2017). Obesity and Overweight Fact Sheet. Retrieved from http://www.who.int/mediacentre/factsheets/fs311/en/.
- 4Keller, A., & Bucher Della Torre, S. (2015). Sugar-Sweetened Beverages and Obesity among Children and Adolescents. A Review of Systematic Literature Reviews. Childhood obesity (Print), 11(4), 338–346. https://doi.org/10.1089/chi.2014.0117
- 5Ervin R.B., Kit B.K., Carroll M.D. (2012). Consumption of Added Sugar among US Children and Adolescents, 2005–2008. National Center for Health Statistics. NCHS Data Brief, No. 87. Retrieved from http://www.cdc.gov/nchs/data/databriefs/db87.pdf.
- 6Gillman MW, Rifas-Shiman SL, Frazier AL, et al. Family dinner and diet quality among older children and adolescents. Arch Fam Med. 2000;9:235-240. doi: 10.1001/archfami.9.3.235.
- Photo of teens by Eliott Reyna on Unsplash (license information)
- Photo of child eating frozen treat by Sharon McCutcheon on Unsplash (license information)