Adolescent Nutrition

2. Adolescent Nutrition Dr.Fatemeh Famouri Pediatric Gastroenterologist

3. ADOLESCENCE • It is the time between the onset of puberty and adulthood (11- 17 years old) • Boys grow about 8 inches, gain about 45 pounds and increase their lean body mass. • Girls grow about 6 inches, gain about 35 pounds and increase their body fat. • Growth through adolescence is hormone driven. Growth spurts for girls begin between ages 10.5 and 11 years with a peak in the rate of growth at around age 12. • Considerable gain in muscle and bone mass

4. Definition • Early adolescence: 10 -15 years; • Mid adolescence: 15-17; • Late adolescence : 17-21, but variable.

5. differences between genders becomes apparent • females: higher fat percentage • males: more lean body mass

6. Adolescence is an uncomfortable time for the teen who is concerned with body image or body changes or athletic activities. Low nutrient snacks are a large part of the diet and adequate amounts of fruits and vegetables are missing. Factors that determine food selection and consumption include the desire to be healthy, fitness goals, amount of discretionary income, social practices and peers.

7. improved nutrition in adolescence,particularly in girls, is the reduced risk of osteoporosis in older age. • stunting becomes a permanent consequence of past malnutrition rather than being a sign of present malnutrition. • If there is indeed catch-up growth in height, adolescence can provide a final chance for intervention to promote additional growth,with potential benefit in terms of physical work capacity and for girls, of diminished obstetric risk • .

8. Linear growth may be limited by multiple simultaneous nutrient deficiencies in many populations, • which could explain that interventions with specific individual nutrients (eg, vitamin A, iron, zinc)

9. increased pre-pregnancy weight and body stores of nutrients, thus contributing to improved future pregnancy and lactation outcome, • improved iron status with reduced risk of anaemia in pregnancy, low birth weight, maternal morbidity and mortality, and with enhanced work productivity and perhaps linear growth; • improved folate status, with reduced risk of neural tube defects in the newborn and megaloblasticanaemia in pregnancy. • Small girls are likely to become small women who are more likely to have small babies, particularly if at a young age

10. The overall nutritional status is better assessed with anthropometry, in adolescence as well as at other stages of the life cycle. Anthropometry is the single most inexpensive, non-invasive and universally applicable method of assessing body composition, size and proportions

11. Iodine deficiency disorders • Iodine deficiency disorders were widely prevalent in most populations • Neuromotor and cognitive impairments of variable degrees • Iodine deficiency is recognized as the most common cause of preventable mental retardation in the world.

12. Zinc • Evidence from supplementation trials suggests that marginal zinc nutriture may also limit skeletal growth • zinc supplementation increased accretion of fat-free mass and enhanced linear growth in those that were stunted at baseline

13. Calcium • ½ of peak bone mass accumulates in adolescence • AI for calcium = 1,300 mg for ages 9–18 years • Inadequate calcium intake can lead to low peak bone mass and is a risk factor for osteoporosis Figure 18.4

14. Teenagers and calcium • Teenagers have high calcium requirements. • Around 50% of the adult skeleton is formed during the teenage years (RNI - boys 1000 mg/day, girls 800 mg/day). • Low calcium intakes (< LRNI) found in 24% of 11-14 year-old girls and 19% of 15-18 year-old girls. • A lack of calcium may have consequences for future bone health e.g. increased risk of osteoporosis.

15. Iron • Additional iron supports muscle growth and increased blood volume • Adolescent females need iron to support menstruation • RDA for iron • Females aged 14–18 years = 15 milligrams • Males aged 14–18 years = 11 milligrams • Iron deficiency is common in adolescence, especially among individuals who limit intake of enriched grains, lean meats, and legumes

16. Iron absorption • Good sources: meat (especially lean red meat), liver and offal, green leafy vegetables, pulses (beans, lentils), dried fruit, nuts and seeds, bread and fortified breakfast cereals. • Iron from meat sources (heme iron) is readily absorbed by the body. • Vitamin C helps the body to absorb iron from other sources (non-heme iron).

17. A healthy diet is important for teenagers Eating a healthy, balanced diet can: • promote wellbeing by improving mood, energy and self-esteem to help reduce anxiety and stress; • best concentration and performance; • reduce the risk of ill-health now and in the future, e.g. obesity, heart disease, cancer, and type 2 diabetes; • increase productivity/attainment and reduce days off sick.

18. Nutrient needs of adolescents • Growth not age should be ultimate indicator of nutrient needs. • Energy needs are greater during adolescence than at any other time of life with exception of pregnancy & lactation. • Energy & Proteins RDAs Males Age (yrs) Kcal/kg Kcal/day Proteins g/kg Proteins gm/day 11-14 55 2500 1.0 45 15-18 45 3000 0.9 59 Females Age (yrs) Kcal/kg Kcal/day Proteins g/kg Proteins gm/day 11-14 47 2200 1.0 46 15-18 40 2200 0.9 44 • Vitamins & Minerals • Higher vitamins and minerals needs. • Three nutrients of importance i.e. vitamin A, iron and calcium. • AI for calcium 1300 mg/day, for iron is 11 mg/day (boys) and 15 mg/day (girls). • Improving fruit & vegetable intake will help in obtaining adequate vitamin A.

19. Dietary recommendations Teenagers should consume a variety of foods from each of the four main food groups: Bread, rice, potatoes, pasta and other starchy foods (33%) Fruit and vegetables (33%) Meat, fish, eggs, beans and other non-dairy sources of protein (12%) Milk and dairy foods (15%)

20. Food Guide Pyramid serving sizes can help you control the amount of calories, fat, saturated fat, cholesterol, sugar or sodium in your diet. • Grains, Bread, Cereal and Pasta form the Base • Fruits and Vegetables • Lean Meat and Fish, Beans, Eggs • Dairy Products • Fats and Sweets

21. Macronutrients - average intakes (Scottish NDNS and Survey of Sugar Intake data)

22. What about dietary fiber? • average dietary fibre intakes to be low in teenagers: - Boys (11-14 years) 11.6 g/day (15-18 years) 13.3 g/day - Girls (11–14 years) 10.2 g/day (15-18 years) 10.6 g/day • Reference values: - 15 g/day (11-14 years) - 18 g/day (15 years or above)

23. What about salt? • NDNS survey results - average salt intakes above recommendations in teenagers: - Boys (11-14 years) 6.75 g/day (15-18 years) 8.25 g/day - Girls (11-18 years) 5.75 g/day (excluding salt added in cooking or at the table • Recommended maximum daily salt intake: - 11 years and over: up to 6 g/day.

24. Teenagers and energy balance • Levels of overweight and obesity are increasing: 35% of teenagers (12-15 years) are classified as overweight or obese (Scottish Health Survey 2009). • Teenagers, especially girls, often try to control their weight by adopting very low energy diets or smoking. • Restricted diets may lead to nutrient deficiencies and other health consequences. • Teenagers of unhealthy weight may need guidance on lifestyle changes to help them achieve a healthy weight.

25. Teenagers – physical activity • Physical activity through life is important for maintaining energy balance and overall health. • At least 60 mins of moderate-intensity physical activity each day is recommended. • Include activities that improve bone health, muscle strength and flexibility at least twice per week. • 68% of boys and 41% of girls (13-15 year-olds) achieve the recommended 60 mins per day

26. Diet and cognitive ability • Food eaten at school can make up a substantial proportion of the diet and have a significant effect on functions such as learning, memory, information processing and mood. • Cognition represents a complex multidimensional set of abilities and cognitive performance is affected by many influencing factors. • Nutritional effects are difficult to measure. Bellisle F (2004) Effects of diet on behaviour and cognition in children Br J Nutr 92 Suppl 2: S227-32. Stevenson J (2006) Dietary influences on cognitive development and behaviour in children Proct Nutr Soc 65(4):361-5.

27. Glycemia The brain appears to be sensitive to short-term fluctuations of glucose supply and therefore it might be beneficial to maintain glycemia at adequate levels to optimise cognition.

28. Eating breakfast • Starting each day with breakfast will supply energy to the brain & body. • Eating breakfast leads to improved energy and concentration levels throughout the morning. • Breakfast consumption may improve cognitive function related to performance in school. • Improvement of memory • Other benefits of breakfast include better nutrient intakes and weight control.

29. Fluids and hydration • Even mild dehydration (1-2%) can lead to headaches, irritability and loss of concentration. This level is not enough to cause feelings of thirst. • The recommendation is to drink 6-8 glasses/day (1.2 litres) to prevent dehydration. People need to drink more when the weather is hot or when they have been active. • All drinks count in terms of fluid intake but those without sugar are best between meals.

30. Diet and IQ • Brain health depends on optimal intakes of nutrients from the diet. • Much speculation about the importance of long chain omega-3 fatty acids to behavioural and cognitive development, including IQ. • Supplementation studies show the best outcome observed in children with learning disabilities. • Current recommendation is one portion of oily fish (140g) per week.

31. Diet and mood/behaviour • There are a number of foods that have a pharmacological effect in the body which affects mood: * caffeine; * vaso-active amines, such as histamine; * tryptophan and serotonin. • There is evidence to suggest that poor vitamin and mineral status may be associated with poor educational attainment and antisocial behaviour.

32. Food additives and hyperactivity • The Southampton study suggested that consumption of mixes of certain artificial food colours and the preservative sodium benzoate could be linked to increased hyperactivity in some children. The colours are: sunset yellow FCF (E110) quinoline yellow (E104) carmoisine (E122) allura red (E129) tartrazine (E102) ponceau 4R (E124) • An EU-wide mandatory warning must be put on any food and drink (except drinks with more than 1.2% alcohol) that contains any of the six colours. Bateman B et al. 2007

33. Eating Habits • irregular eating habits • snacks generally provide ¼ of daily energy intake • more fast food: less fruits, vegetables, milk • food choices are often dictated by peers

34. What do boys and girls want? • boysys usually want to gain muscle and get taller • Girls usually want to control their weight

35. For girls some addition of fat is natural • Need at least 17% body fat for normal periods • Diet is a four letter word • Improve eating habits and activity – but don’t starve or over exercise

36. Boys mature later • Growth spurt up to 2 years later than girls • Full muscle mass doesn’t develop until one year after full height achieved • Excess calories and protein won’t speed things up

37. Make every drink count • Cut the soft drinks • Drink 3-4 cups of milk • Drink at least 4 more cups • of water or juice (watch the juice – it has calories)

38. During a sports event • Drink at least 2 cups of water before event • Continue to drink 4 ounces every half hour • Cool, not cold, water is best • Replace two cups of fluid for every pound lost

39. Eat at least 5 servings of fruits and vegetables • Lots of vitamins and minerals with few calories • More fiber so you feel full • Portion size – palm of girl’s hand

40. Eat more whole grain breads and cereals • Won’t cause weight gain if don’t eat too much • Depending on body size, will need 6-11 servings • Portion size – the palm of a girl’s hand

41. Get enough protein but not too much • Get protein from lean meat, fish and poultry • Portion size – palm of girl’s hand • Protein also comes from dairy foods, dried beans and peas, peanut butter, nuts, seeds, soy foods

42. Limit low nutrient foods with lots of fat, sugar and sodium • Make fast food a special occasion • choose grilled or broiled meat, fish or poultry • choose side salads, baked potatoes • choose milk, water or juice

43. Disordered Eating • Disordered eating patterns are more prevalent in adolescent females than males • May be linked with poor body image or low self-esteem • Teens often adopt unhealthy habits such as • Skipping meals • Using food substitutes • Taking diet pills or nutritional supplements • Purging through vomiting, laxatives, or diuretics • Eating family meals promotes healthy eating patterns

44. Anorexia Nervosa • Refusal to maintain body weight over a minimal normal weight. • Intense fear of gaining weight or becoming fat, even though underweight. • Denial of low body weight. • In females, absence of at least 3 consecutive menstrual cycles. .

45. Anorexia Nervosa:Clinical & Laboratory Findings • LANUGO and EDEMA of the skin, bradycardia and hypotension, constipation, normochromic anemia and leukopenia, hyponatremia, hypoglycemia, low hormonal levels (estrogen or testosterone, LSH, FSH) but normal TSH and increased cortisol • SKELETAL CHANGE: OSTEOPENIA

46. Anorexia NervosaSigns of Malnutrition : • Easy pinching in the posterior region of the arms, due to to loss of fat • Hollowing temporal muscles • Wasting of the tigh muscles • Easily plucked hairs MEMO: the laboratory signs of malnutrition are HYPOALBUMINEMIA and HYPOPREALBUMINEMIA

47. Treatment for Anorexia Nervosa • Close supervision • Individual and family counseling • Self-acceptance • Time and patience • Nutrition therapy

48. Bulimia Nervosa • Characterized episodes of binge eating alternating with purging • Female to male ratio 10:1 • Some genetic factors may be involved, but and above all cultural attitudes toward standards of physical attractiveness • 3 modalities are the most frequent: • Self induced vomiting via “fingers” or ipecac • Abuse laxatives (e.g. bisacodyl, cascara or senna) • Misuse diuretics • In addition to diuretics also diet pills (containing ephedrine)

49. Bulimia Nervosa: Complications • Oral: loss of enamel of the anterior teeth and dental caries • GI tract: frequent vomiting can induce GE-reflux (occasionally tears in the esophagus). The abuse of laxatives can lead to constipation due to damage of the myo-enteric plexus • Abnormalities of the electrolytes: • Metabolic alkalosis due to frequent vomiting • HYPOKALEMIA present in 5% of the patients

50. Bulimia Nervosa: Treatment • Replenish potassium losses • Eventually I.V. fluids and lytes • Monitor lytes frequently and, of course • Refer for psychiatric or psychologic counseling