module 8: adolescents
Describe various influences on eating behaviors of adolescents
-Individual influences (intrapersonal) Knowledge Beliefs Self-efficacy Food preferences Hunger (related to physical growth) Meal/snack patterns Weight-control behaviors Time restraints Economic restraints -Social environmental influences (interpersonal) Family Peer network -Social environmental influences (interpersonal) Family Peer network Availability of foods Transportation to food outlets -Macrosystem influences (societal) Media/advertising Local, state, and national food production and distribution systems Laws (e.g., school nutrition policies) Cultural norms
Explain why teens are at increased risk for iron-deficiency anemia.
-Iron deficiency is quite common (~10%) among adolescent females (Looker, 1997) Iron deficiency without anemia is more prevalent than iron deficiency anemia Compared to White females, Black and Mexican American females are at higher risk for iron deficiency. Compared to teens from middle- and high-income families, teens from low-income families are at higher risk for iron deficiency. -Increased demand for iron to support rapid growth and increase in blood volume -Teens may have inadequate dietary intake of foods rich in iron and/or vitamin C Skipping meals Adoption of vegetarian (especially vegan) dietary patterns Calorie restriction for weight control -Increased iron losses Endurance sports Heavy menstrual bleeding
Describe treatment for iron-deficiency anemia.
-Once iron-deficiency anemia develops, dietary changes in iron intake are NOT sufficient to correct the deficiency; iron supplementation is necessary. -Consume iron-rich foods: Lean meats Legumes Iron-fortified breakfast cereals -Consume dietary sources of vitamin C along with iron-rich foods to enhance absorption of iron. -Avoid use of dairy products, calcium supplements, coffee, tea, and high-fiber foods within 1 hour of taking dietary supplements, as these may decrease iron absorption.
describe how the following factors influence bone mass.
-hormones: estrogen, testosterone, and growth hormone all stimulate bone growth and development. -Body weight: low energy availability (i.e., abnormally low body fat) decreases production of the aforementioned hormones, which can limit bone growth and development. Higher body weight is associated with higher bone mineral density. -Exercise: the stress of weight-bearing exercise on bones stimulates bone remodeling in such a way to increase bone mineral density. Examples of weight-bearing exercise include walking, running, and weight-lifting. -Meet the RDA for bone-building nutrients to support optimal bone growth and development: Calcium Phosphorus Magnesium Vitamin D Vitamin K -Avoid excessive intakes of nutrients that can impair calcium absorption or increase calcium excretion: Excessive fiber intake can reduce calcium absorption from the small intestine. Excessive phosphorus intake (e.g., from soft drinks) coupled with an inadequate calcium intake may increase bone resorption and increase urinary calcium excretion (Linus Pauling Institute, 2014 (Links to an external site.)). Excessive sodium intake can increase urinary calcium excretion. -Cigarette smoking: smoking impairs bone growth and development. -Alcohol: alcohol impairs bone growth and development. -Caffeine: Historically, health professionals have been concerned that a high intake of caffeine (>400 mg/d) may increase urinary calcium excretion and thereby lower bone mineral density. However, a recent systematic review found scant evidence that high intakes of caffeine negatively impact bone health (Wikoff et al, 2017). The more important concern is that higher intake of caffeinated beverages is correlated with lower intake of nutrient-dense sources of bone-building nutrients (e.g., milk).
Calculate protein needs of adolescents.
4 to 13 years of age: 0.95 g/kg/d 14 to 18 years of age: 0.85 g/kg/d
Recall Physical Activity Guidelines for adolescents.
60 minutes per day of moderate- or vigorous-intensity aerobic activities (should be vigorous at least 3 times per week) Include muscle-strengthening activities as part of those 60 minutes per day on at least 3 days per week. Include bone-strengthening activities as part of those 60 minutes per day on at least 3 days per week.
Recall approximate fluid needs of adolescents (may vary based on climate, physical activity).
9 to 13 years:Males: 2.4 L/d (~10 cups/d) of total water (foods and beverages); drink ~ 8 cups of fluids per dayFemales: 2.1 L/d (~9 cups/d) of total water (foods and beverages); drink ~ 7 cups of fluids per day 14 to 18 years:Males: 3.3 L/d (~14 cups/d) of total water (foods and beverages); drink ~ 11 cups of fluids per dayFemales: 2.3 L/d (~10 cups/d) of total water (foods and beverages); drink ~8 cups of fluids per day
Discuss the fat intakes of adolescents.
AMDR: 25% to 35% of total kcal (most teens are within this range) Dietary Guidelines: limit saturated fat intake to no more than 10% of total kcal (most teens exceed this amount)
Describe dietary and lifestyle changes to treat metabolic syndrome and type 2 diabetes among adolescents.
Achieve and maintain healthy body weight. Engage in regular physical activity. DASH diet is a healthy dietary pattern; may need to incorporate carbohydrate counting.
Discuss the calcium status of adolescents
Adolescence is a period of rapid bone accretion (about 1/2 of peak adult bone mass). Males have higher bone mineral density (BMD) than females. Compared to all other age groups, the RDA for calcium is highest during adolescence: 1300 mg/d. Many adolescents, especially females, do not meet the RDA for calcium. This sets the stage for osteoporosis later in life
Recall the prevalence of overweight and obesity among adolescents (Skinner et al, 2018 (Links to an external site.))
Ages 12 to 15 years38.7% have BMI-for-age ≥ 85th percentile 20.6% have BMI-for-age ≥ 95th percentile Ages 16 to 19 years41.5% have BMI-for-age ≥ 85th percentile20.5% have BMI-for-age ≥ 95th percentile
Discuss how the declining frequency of family meals influences nutritional status of adolescents.
Among teens, >1/3 food intake is outside home. Meals eaten outside the home tend to have: More added sugars More solid fats You have learned about the many benefits of family meals for physical and mental health. Low frequency of family meals may be linked to: Decreased quality of food choices Negative body image Increased likelihood of risky behaviors (e.g., smoking, alcohol, drugs) Worsened academic outcomes
Assess growth of adolescents.
BMI-for-age is still the preferred growth chart:Girls BMI-for-Age (Links to an external site.)Boys BMI-for-Age (Links to an external site.) Body fat measurements (e.g., skinfolds) may be tracked over time, but should not be evaluated against adult norms.
Discuss how meal skipping influences nutritional status of adolescents.
Breakfast is the most commonly skipped meal (only 38% of teens eat breakfast daily). Skipping breakfast has a negative impact on nutrient adequacy, especially for: Energy Protein Fiber Calcium Folate Counsel teens to eat frequently throughout the day, using convenient, portable, healthy choices.
Discuss ways communities can promote healthy eating and physical activity.
Built environment should provide safe, accessible spaces for physical activity. Provide nutrition education for parents and teens at community centers, places of worship, supermarkets, etc. Provide space and supplies for community garden.
Describe dietary and lifestyle changes to treat hyperlipidemia among adolescents.
CHILD 1 guidelines (review Module 7), which includes DASH recommendations plus additional guidance on fat intake, fiber intake, and family meals
List implications of adolescent overweight and obesity (beginning in adolescence, progressing into adulthood).
Cardiovascular problems (hypertension, dyslipidemia) Endocrine problems (type 2 diabetes) Respiratory problems (asthma, sleep apnea) Bone and joint problems (injuries, arthritis) Liver problems (fatty liver) Mental health problems (depression)
Describe use of supplements by adolescents.
Commonly used dietary supplements among adolescents include MVMs, iron, vitamin C, calcium, vitamin E, and B complex. Besides vitamin and mineral supplements, teens also may use herbal supplements or sports supplements (i.e., ergogenic aids). In general, adolescents who use vitamin and mineral supplements already have adequate diets and a variety of healthy behaviors. In other words, the teens who actually need supplements aren't likely to take them! Use of herbal products or sports supplements by teens is cause for concern because dietary supplements are not well regulated, may have dangerous side effects, and typically have not been tested among younger populations.
List potential effects of iron-deficiency anemia.
Delayed or impaired growth and development Fatigue Impaired immune function Impaired physical performance Increased susceptibility to lead poisoning For pregnant teens: increased risk of preterm birth or LBW infant
Recall usual energy needs of adolescents (large variability due to growth and activity levels).
Due to the demands of growth (muscle, bone, and adipose tissue) and increased body mass, the total energy requirement of adolescents (kcal/d) are the highest of all stages of the life cycle. (NOTE: Relative energy needs (kcal/kg) are highest during infancy.
Recall that health practitioners should use their professional judgment in interpreting DRIs for adolescents in light of sexual maturation rating.
EXAMPLE: For a girl who is an "early bloomer " (i.e., menarche at age 10), it may be appropriate to emphasize iron-rich foods to prevent iron deficiency, even though the upward shift in the RDA for iron for girls does not occur until age 14.
Relate health education strategies to stage of psychological and cognitive development.
Early adolescence Characteristics: concrete thinking (as opposed to abstract thinking), egocentrism (i.e., focus on self; ignores the impact of personal actions on outside world), impulsive behaviorTo reach young adolescents, health education should focus on immediate consequences of eating and exercise behaviors (i.e., right here, right now)Physical attractivenessAcademic abilityPhysical performance (i.e., sports) Middle adolescence Characteristics: emotional and social independence from family, dominant influence of peers, emergence of abstract thinking (but little life application)Health education should still provide concrete, understandable examples. Late adolescenceCharacteristics: development of personal identity, moral beliefs, reduced economic and emotional dependence on family, improved abstract thinkingHealth education may employ motivational counseling. Appeal to older adolescents by encouraging them to take charge of their own health.
Summarize nutrition strategies used in the treatment of RED-S.
Early intervention is crucial to limit bone loss. Sex hormones are important influencers of bone formation, so imbalances in estrogen or testosterone negatively impact bone mineral density (DeSouza, 2019). Sometimes hormonal medications are prescribed for females to restore regular menstrual cycles, but increasing energy intake (and body weight) is a better tool to correct hormonal imbalances. Daily energy intake should be at least 30 kcal/kg of fat free mass, preferably 45 kcal/kg FFM/d (Weiss-Kelly, 2016). Meeting these high calorie goals may require setting aside time for several meals and snacks throughout the day and creative use of energy-dense foods. To restore bone mineral density (as much as possible), calcium (to reach the RDA of 1300 mg/d) and vitamin D supplements (600 IU/d) are usually recommended. Besides nutritional interventions, it may be necessary to reduce training volume until health is restored.
Suggest ways to prevent RED-S.
Educate athletes, parents, coaches, and trainers that amenorrhea or oligomenorrhea among female athletes is NOT normal and has serious consequences. Nutrition education should focus on healthy eating behaviors, not on achieving a specific body weight, BMI, or % body fat. Promote foods that are good sources of bone-building nutrients. (Be sure that you can list the nutrients involved in bone health. Also, be sure you can provide examples of food sources of these nutrients. If you need to review, see Module 1.)
Identify strategies to prevent eating disorders.
Encourage healthy weight management strategies; discourage restrictive dieting and fasting (except for religious occasions) Provide information about normal body fat changes that occur during puberty Carefully phrase weight-related recommendations and comments Focus on healthy behaviors rather than a number on the scale Encourage children/adolescents to eat/stop eating in response to internal cues for hunger and satiety Provide adolescents with appropriate, but not unlimited, degree of independence, choice, responsibility, and accountability for their own actions Build respectful and supportive relationships (parents, teachers, coaches) Educate young athletes that thinness is not necessarily associated with better sports performance Establish screening and support programs at high schools and colleges
Recall nutrition education and counseling strategies that are effective when working with adolescents.
Establish trust and rapport. Consider the level of the educational materials. Materials should not be as complex as materials for adults (to facilitate comprehension), but not too childish (to avoid insulting their intelligence). Involve the teen in decision-making to improve rapport and compliance: Allow teens to have some say in the choice of topics to discuss. Allow teens to set their own nutrition goals. They'll be more motivated to take ownership of a self-prescribed goal.Allow teens to have a say in developing the behavioral strategies they will employ to meet their health goals. Limit to one or two goals per session. Supply concrete recommendations (e.g., specific number of servings of fruit per day) rather than abstract recommendations (e.g., increase your fruit intake). Relate behavioral changes to immediate, relevant benefits:Academic performanceAthletic performanceAppearance Frequent follow-up Use of technology
Recall the major provisions of the Healthy Hunger Free Kids Act of 2010.
Extended funding for the Child Nutrition Program Expanded access to free (family income <130% poverty level) and reduced lunches (family income <185% poverty level) Required schools to develop wellness policies Established nutrition standards for foods served at school are displayed below. You don't need to memorize the school breakfast and lunch recommendations shown below; they are here as a resource in case you need to look them up. One important fact to remember about school lunch is that meals are designed to meet 1/3 of the RDA for protein, calcium, iron, vitamin A, and vitamin C (on average). School breakfasts are designed to meet 1/4 of the RDA for those same nutrients. In 2018, a new law loosened some of the nutritional guidelines to improve student acceptance of school breakfast and lunch options. Whole grains are preferred, but schools can also include some refined grains. Also, chocolate milk is now allowed as an alternative to plain milk.
Recall usual age and sequence of pubertal development among males and females.
From these two charts, note that the typical pubertal growth spurt occurs about 1 year earlier among girls than among boys
Recognize that body dissatisfaction is common among adolescents.
Girls may be overly concerned about normal increases in body fat that occur during puberty Boys may be concerned that they are developing muscle mass at a slower rate than their peers Youth are highly susceptible to media's portrayal of ideal body
How well do teens adhere to the Dietary Guidelines and MyPlate?
Grains: on average, teens get enough grains, but not enough whole grains (Albertson, 2016) Fruits: on average, teens are well below goals for servings of fruit per day. In recent years, fruit intake among children and teens has increased slightly, but still does not meet the recommendations of Dietary Guidelines (Kim, 2014). Vegetables: on average, teens are well below goals for servings of vegetables per day (Kim, 2014) Protein foods: on average, adolescent males meet goals for servings of protein foods; adolescent females do not Dairy: on average, teens are well below goals for servings of dairy products per day Sodium: teens (and Americans, in general) far exceed sodium recommendations (Quader, 2017) Saturated fat: on average, teens exceed recommended limits for saturated fat Added sugars: on average, teens exceed (by nearly 2X) recommended limits for added sugar
List physiological and psychological benefits of physical activity.
Improved aerobic endurance Improved muscular strength Reduced risk of childhood obesity Increased bone mineral density Improved self-esteem
Recognize that appropriately planned vegetarian diets can support health at all stages of the life cycle.
Inquire about reasons for choosing vegetarian diet. Be alert for signs of eating disorders (vegetarian diets may be used as a socially acceptable way to restrict food choices). Educate vegetarian (especially vegan) teens about dietary planning to ensure adequate intake of vitamin B-12, iron, zinc, calcium, vitamin D, and omega-3 fatty acids. Strategies to ensure nutrient adequacy: Choose fortified foods. Read labels to identify good food sources of needed nutrients.Use dietary supplements to fill nutrient gaps when appropriate.See suggested dietary pattern.
Describe dietary and lifestyle changes to treat hypertension among adolescents.
Loss of excess weight (if needed) DASH Diet (review Module 1)
Recall the RDA for iron for adolescents.
Males (age 14 - 18): 11 mg/d Females (age 14 - 18): 15 mg/d
Identify factors that are positively associated with physical activity among adolescents.
Males are more likely to be physically active than females Higher self-confidence, self-efficacy (Links to an external site.) Enjoyment of activity Perceived positive benefits (e.g., fun, fitness, appearance) Family affluence Peer and family support Economic and geographic access to safe and convenient space and equipment
Discuss the folate status of adolescents.
Many adolescent females do not meet the RDA of 400 micrograms of folate per day. Consequences Macrocytic (a.k.a. megaloblastic) anemia Birth defects (in offspring) Just to review, here is some basic information about folate:
Recognize how biological changes of adolescence affect body image.
Many adolescent girls are distressed about natural increases in body fat. This may lead to disordered eating and excessive exercise behaviors. Late-developing adolescent males may be distressed about slow muscle gains. This may lead to disordered eating and use of steroids and inappropriate dietary supplements. Early sexual maturation of girls (related to overweight/obesity) has been linked to poor body image, smoking, alcohol use, and sexual promiscuity.
Discuss treatment of adolescent overweight and obesity.
Multi-staged approach, based on BMI-for-age and presence of other health conditions (the higher the BMI, the more structured the approach) Stage 1: Prevention Plus: general advice to choose age-appropriate portions for more nutrient-dense, less energy-dense foods, increase physical activity/decrease screen time Stage 2: Structured Weight Management: add monitoring of food/activity, further limit screen time, utilize goal-setting Stage 3: Comprehensive Multidisciplinary Intervention: more structured, more frequent contact, include health professionals from multiple disciplines (e.g., physician, nurse, RDN, mental health counselor) Stage 4: Tertiary Care Intervention: work with professionals at a specialized weight management center for adolescents, may involve very-low-calorie diet (VLCDs), weight-loss medications (e.g., orlistat), and/or bariatric surgery
Describe elements of treatment for eating disorders.
Multidisciplinary approach: Physician Nurse Dietitian Psychologist Intensity of therapy depends on severity of physical effects of eating disorder: Outpatient program Day treatment program Inpatient program Overall goals Restore healthy body weight Improve social and emotional well-being Normalize eating behaviors
Describe orthorexia.
Orthorexia is not a formally recognized eating disorder in DSM-5, but it is an emerging pattern of disordered eating that may negatively impact physical and mental health. Orthorexia is defined as an obsession with proper or healthful eating. Healthy eating itself is not a problem, but when strict food rules begin to interfere with quality of life and result in physical or mental health problems, intervention is warranted.
Understand why parents should also be targets of nutrition education for adolescents.
Parents (or other caregivers) are the gatekeepers of foods; kids tend to eat what's available, so make fruits and vegetables more available and more visible than empty-calorie foods. Although teens are establishing independence, parents can still be role models of healthy eating behaviors.
Discuss ways schools can promote healthy eating and physical activity.
Provide high-quality school breakfasts and lunches that comply with federal guidelines. Implement physical education and provide opportunities and safe environments to be physically active during leisure time. Implement health education that provides students with the knowledge, skills, and experiences needed for lifelong healthy eating (and other lifestyle) habits. Partner with families and community organizations to promote lifelong healthy eating (and other lifestyle) habits. Provide wellness resources to faculty and school staff. Employ (and provide continuing education for) qualified individuals to provide nutrition services, health education, and physical education to students.
Discuss the vitamin D status of adolescents.
RDA for vitamin D is 15 micrograms per day. Low levels of vitamin D are extremely common among adolescents (and all Americans), due to: Low sun exposure (cold climate, Northern latitude, use of sunscreen, dark skin pigmentation) Low intake of fatty fish and fortified dairy products Low vitamin D has been found to be associated with Low bone mass Elevated blood pressure Hyperglycemia Dyslipidemia Higher BMI Abdominal obesity American Academy of Pediatrics and National Academy of Medicine (formerly Institute of Medicine) recommend dietary supplementation with 10 micrograms of vitamin D per day for anyone who does not meet the RDA with dietary sources. st to review, here is some basic information about vitamin D. This slide comes from the Linus Pauling Institute. I like these slides because they provide succinct summaries of important information about the micronutrients, but please note that the researchers who run the Micronutrient Information Center at LPI disagree with the current RDA and UL for vitamin D. The RDA is 15 mcg, but LPI thinks it should be higher. The special notes section explains this.
Discuss the fiber intakes of adolescents.
Recommended fiber intake is 14 g/1000 kcal Adolescents typically consume less than half of the recommended amount of fiber. This is because intakes of fruits, vegetables, and whole grains tend to be low among adolescents.
Describe ways to identify RED-S in athletes.
Regular physical check-ups (e.g., at the start of the training season) are encouraged. Ask about menarche and the regularity of the menstrual cycle. If a female has not started menstruating by age 15, or if cycles are irregular or absent after menarche, refer to an OB/GYN. Also consider the possibility that birth control pills may be artificially regulating menstrual cycles. Stress fractures (especially if the athlete has more than one stress fracture) are a possible sign of low bone mineral density, which could be due to RED-S.
Describe Relative Energy Deficiency in Sport (RED-S; formerly called Female Athlete Triad).
Relative Energy Deficiency in Sport (RED-S) is a syndrome of altered metabolism, immune function, and mental health caused by low energy availability in athletes. Low energy availability may be due to unintentional failure to meet the high energy demands of sports or intentional restriction of energy intake to control body weight. In the past, this condition was called Female Athlete Triad, but researchers now recognize that low energy availability leads to a spectrum of health problems in male athletes, too.
identify warning signs of eating disorders
Restrained eating (i.e., extreme dieting) is the leading predictor of eating disorders.
Describe the use of the Sexual Maturation Rating (SMR) scale (i.e., Tanner stages).
Scale of secondary sexual characteristics (e.g., enlargement of breasts, male genitalia, development of pubic hair) used in the assessment of adolescent growth and development The order of the stages does not vary, but the age of onset, duration of each stage, and overall tempo of pubertal development may vary among individuals. Stage of sexual maturation is better than chronological age for assessing the biological growth and development of adolescents
biological changes that occur during adolescence.
Sexual maturation Increases in height and weight Changes in body composition (i.e., % body fat) Accretion of skeletal mass
Discuss how usual snacking behaviors influence nutritional status of adolescents.
Snacks account for ~25% of overall calorie intake of adolescents. Typical snack choices are high in calories, fat, added sugars, and sodium, but relatively low in vitamins and minerals. Significant sources of calories, fat, and sugar in teen diets: Soft drinks are the #1 source of energy and added sugars in adolescent diets Fruit drinks Dairy desserts Salty snacks Pizza Counsel to improve food choices; promote snacks as an opportunity to consume nutrient-dense foods
Recognize that weight-related eating behaviors exist on a continuum.
Some concern about body weight and shape is normal. Disordered eating: temporary changes in diet behaviors, no lasting impact on health. Eating disorder: prolonged unhealthy changes in diet behaviors, interferes with other aspects of daily life, lasting health consequences.
Discuss how substance use can affect nutritional status of adolescents.
There are many reasons why substance use can contribute to malnutrition: Changes in appetite and food intake Decreased nutrient absorptionIncreased nutrient excretion Decreased financial resources to purchase food Altered cognitive function Specific substances have nutritional effects: Tobacco use increases vitamin C requirements (to combat oxidative damage) Alcohol use alters intake, absorption, metabolism, and excretion of B vitamins Teens who use tobacco, alcohol, and illicit drugs are at increased risk for disordered eating
Recall that eating disorders are the result of an interplay between genetic and environmental factors.
There is now general acceptance among the scientific community that eating disorders (like other mental disorders) are biologically-based (i.e., there is a genetic component). Cultural emphasis on extreme thinness Stressful life situations (e.g., grief, anxiety, abuse) Most experts now agree that it is not helpful to blame the family for development of eating disorders.
Describe body composition changes that occur during puberty.
Weight gain: during puberty, adolescents gain as much as 50% of their adult healthy body weight. Among females, fat mass increases more than lean mass so overall % body fat increases (potential cause of distress). The most rapid weight gain occurs prior to menarche. Females gain ~20 lb during the first year of the adolescent growth spurt, but this rate of weight gain typically slows down to ~5 lb/y by the end of puberty. Among males, lean mass increases more than fat mass, so overall % body fat decreases. The overall weight gain during adolescence is usually higher for males than for females (~35 pounds for females and ~45 pounds for males). Accretion of bone mass: As much as 50% of adult bone mass accrues during adolescence.
Recall nutritional concerns of adolescents who choose vegetarian dietary patterns.
Well-planned vegetarian diets can offer many health advantagesHigher fiber Lower saturated fat Higher levels of some vitamins and minerals that tend to be low in adolescent diets (e.g., potassium, magnesium, folate, vitamin E) Lower risk of overweight/obesity Vegetarian diets that are not well planned (especially strict vegans) may place the adolescent at higher risk for nutrient deficiencies. For this reason, a vegetarian dietary pattern is considered a risk indicator that warrants further nutritional assessment. Protein (If overall calorie intake is adequate, protein needs are usually met, although protein quality may be a concern. If overall calories are inadequate, protein is likely to be inadequate.)Calcium Zinc Iron Omega-3 fatty acids Vitamin D Vitamin B-6 Vitamin B-12
Pubarche
appearance of pubic and axillary hair, sebaceous glands, and axillary glands
Thelarche:
beginning of breast development
spermarche
beginning of sperm production by the testesAverage age: 14 y
Describe how high levels of physical activity may influence nutritional needs of adolescents.
increased energy needs increased protein needs increased fluid needs
Menarche
the first occurrence of menstruation onset of menses Average age: 12.5 y Early onset among overweight/obese girls Late onset among underweight girls A general observation is that ~25% body fat required for regular ovulatory cycles to begin
