Adolescent Nutrition Lecture 20 PDF

ADOLESCENT NUTRITION LECTURE 20 Learning Objectives Discuss how developmental stages determine nutrient intake and growth. Discuss the physiological and psychosocial changes in this age group. Discuss key nutrition and behavioral aspects in this age group. List and discuss nutrients re...

ADOLESCENT NUTRITION LECTURE 20 Learning Objectives Discuss how developmental stages determine nutrient intake and growth. Discuss the physiological and psychosocial changes in this age group. Discuss key nutrition and behavioral aspects in this age group. List and discuss nutrients required in this age group. Definition of this stage Period between 11 & 21 years of age Biological Social Cognitive changes changes changes Nutritional challenges - Increased needs for energy, protein, vitamin, minerals - Health compromising behaviors such as meal skipping, unhealthy weight control behaviors  - Sexual Maturation - ↑ Height and Weight - ↑ Skeletal mass - Body composition change Puberty: time frame during which the body matures from that of a child to an adult  Can you guess the age? Can’t rely on age alone in evaluating pubertal growth. An assessment of the degree of maturation of secondary sex characteristics is useful Sexual Maturation Rating (SMR) “Tanner stages” Scale of secondary sexual characteristics to assess degree of pubertal maturation  Does not consider chronological age For females - breast development & pubic hair growth For males - genital development & pubic hair growth Tanner stage - Females SMR 1 = prepubertal growth & Peak development Onset of linear velocity, end SMR 2 through 5 = occurrences of growth spurt of stage 2 puberty SMR 5 = sexual maturation concluded Who is likely to have early menarche? Who is likely to have late menarche? Tanner stage - Males SMR 1 = prepubertal growth & development Peak velocity, SMR 2 through 5 = occurrences of puberty middle of stage 4 SMR 5 = sexual maturation concluded Body Composition Changes - Females During puberty  Gain 1.14kg (2.5lb) / year of fat mass  Body fat levels peak at 15-16 years of age  17% body fat required for menarche  25% body fat for development/maintenance of regular ovulatory cycle At full maturity  Lean body mass ↓ from 80% to 74% body weight  Fat mass ↑ from 16 to 26% body weight Body Composition Changes - Males  Peak weight gain coincides with peak linear growth, peak muscle mass accumulation  Body fat ↓ to 12% by end of puberty Body Composition Changes  Half of ideal adult body weight gained  Half adult peak bone mass is accrued  90% of adult skeletal mass formed by age 18yr So, why is that important nutritionally? Critical time for osteoporosis prevention Adequate dietary intake important calcium, vit D, vit K, protein, phosphorus, magnesium, and iron Psychosocial Changes – Three stages Early adolescence (11-14 yr) characteristics - Willing to do anything that will improve their body image - Want immediate results - Concrete thinking - Impulsive behavior  Lack ability to see how current actions influence future  Females maturing early, eating problems, poor body image  Males maturing late, feel physically inferior  Peer influence What are some counseling goals? Short term daily concerns; focus on nutritional concerns that affect appearance or physical performance (acne, sports, weight) Psychosocial Changes - Three stages Middle adolescence (15-17 yr) characteristics  Listen to peers more than parents or other adults  Becoming more in charge of the food they eat  Development of abstract reasoning continues, still revert back to concrete thinking  Feel invincible  Use of diet pills, laxatives, alcohol etc. What are some counseling goals? Concrete, understandable examples Wise food selections away from home Psychosocial Changes - Three stages Late adolescence (18-21 yr) characteristics  Established body image  Thinking about the future and are more interested in improving overall health. What are some counseling goals? Address long-term goals Key Nutrition Concepts  Key Concept #1 Nutrition needs should be determined by the degree of sexual maturation and biological maturity (biological age) instead of by chronological age.  Key Concept #2 Unhealthy eating behaviors are common - frequent dieting - meal skipping - unhealthy dietary practices - frequent consumption of foods high in fat and sugar - fast foods, soft drinks, and energy-dense snacks. Key Nutrition Concepts  Key Concept #3 Concrete thinking and abstract reasoning abilities do not develop fully until late adolescence or early adulthood; therefore, education efforts need to be highly specific and based on concrete principles.  Key Concept #4 Adolescent eating behaviors are influenced by a variety of factors - including peers, parents, food availability, food preferences, cost, conveniences, personal and cultural beliefs, mass media, and body image Key Nutrition Concepts  Key Concept #5 Family meals decline, but they are important in improving the nutritional quality of adolescent diets.  Key Concept #6 - Small number of adolescent are meeting nutritional requirements for fruits, vegetables, whole grains, and calcium. - Many exceed daily energy requirements Key Nutrition Concepts  Key Concept #7 Nutrition messages for adolescents need to focus on what is important for their lives. - Focus on the present and how good nutrition can positively impact appearance, sports performance, or academic performance - Likely to have a greater impact than focusing on long-term disease prevention. Key Nutrition Concepts  Key Concept #8 - Calcium intake is important during adolescence for development of peak bone mass. - Participation in physical activity during adolescence also plays a role in the development of bone mass. - Importance of establishing good habits early, i.e. milk with every meal. Snacking, Meal Skipping, Eating Away from Home Behaviors  ↑ proportion of calories and nutrients from “snacking”  Larger proportion of calories from snacking away from the home, often at fast food restaurants. Soft drinks are most common snack  High in sugar, sodium and fat, low in vitamins, minerals  Breakfast and lunch = commonly skipped meals Body Image Desire to change rate of growth or body proportions by manipulating diets in a negative way Girls = over-restrict the amount of food they eat Boys = tempted to use nutritional supplements, hoping to achieve the muscular appearance of adulthood Energy Requirements  Varied change in lean mass, fat mass, skeletal mass, so values extrapolated from adults  Influenced by: - activity level - basal metabolic rate (BMR) - pubertal growth & development Low intakes linked to: - reductions in linear growth - delays in sexual maturation - reduced lean body mass Protein Requirements of Adolescents  Protein requirements influenced by protein needed: - to maintain existing lean body mass - for growth of new lean body mass  DRI 0.85 g/kg BW Estimate protein needs based on timing of growth that chronological growth Other Nutrients  Carbohydrates - Primary source of dietary energy - 130 g/day or 45-65 % of daily calories  Dietary fiber Important for normal bowel function and may play a role in disease prevention - 26 g/day for adolescent females - 31 g/day for males