Life Cycle Nutrition: Nutrition in Adolescence & Eating Disorders PDF

Life Cycle Nutrition: Nutrition in Adolescence and Eating Disorders WARNING – EATING DISORDERS WILL BE DISCUSSED IN THIS CLASS IF IMAGES OF PEOPLE WITH EATING DISORDERS IS TRIGGERING, PLEASE USE THE BLURRED VERSION OF THIS LECTURE RECORDING. THE CONTENT IS...

Life Cycle Nutrition: Nutrition in Adolescence and Eating Disorders WARNING – EATING DISORDERS WILL BE DISCUSSED IN THIS CLASS IF IMAGES OF PEOPLE WITH EATING DISORDERS IS TRIGGERING, PLEASE USE THE BLURRED VERSION OF THIS LECTURE RECORDING. THE CONTENT IS THE SAME, BUT THE IMAGES HAVE BEEN BLURRED. (THE PDF OF THE SLIDES HAVE THESE IMAGES REMOVED) ALSO NOTE THAT THESE IMAGES ARE DISPLAYED IN THE TEXTBOOK (CHAPTER 9 – CONTROVERSY)  Life Cycle Nutrition: Nutrition in Adolescence and Eating Disorders Faculty of Science | Department of Biochemistry The Teen Years Teenagers are not fed; they eat! Busy lives – school, part‐time jobs, extra‐curricular sports, social activities Rapid body changes Phenomenal societal pressures (peers, media, parents….) Be thin, have clear skin, look cut….and get good grades…. Life’s pressures can lead to risky behaviours Alcohol and drug abuse, over‐use of supplements, disordered eating Faculty of Science | Department of Biochemistry The Teen Years Adolescent growth spurt Girls: begins ~10 years, peaks at ~12 years Boys: begins ~12 ‐ 13 years, peaks at ~14 years Girls gain more weight as body fat compared to boys High nutrient requirements for growth occur at the same time as the quality of the diet tends to decline More independence in food choices, less time at home Teens tend to be very large consumers of fast‐ food/convenience food, sugar‐sweetened soft drinks, salt‐sugar‐fat foods (invincible?) Low intakes of fruits & veggies, lower intake of milk and dairy https://www.nutrition.org.uk/healthyliving/lifestages/teenagers.html Faculty of Science Department of Biochemistry Bone Growth in Adolescence Rapid linear bone growth occurs at the epiphyseal plate (growth plate) of long bones Growth plate closes near the end of puberty which limits height growth Large amounts of mineral (Ca, P, Mg) is laid down in new bone Peak bone mass achieved as a young adult will determine life long bone health and later risk for osteoporosis Physical activity (weight‐bearing) will improve bone mineralization Faculty of Science | Department of Biochemistry Soft Drink and Milk Consumption by Adolescents Faculty of Science | Department of Biochemistry Iron Requirements for Adolescents Iron requirement increases in males to expand lean muscle mass (from 8 mg to 11 mg, then back to 8 mg by early 20s) Iron requirement increases in females to support lean mass expansion, and menstruation (8 mg to 15 mg to 18 mg and back to 8 mg after menopause) Men: Requirement returns to pre‐adolescent level in early adulthood Women: Requirement returns to pre‐adolescent level at menopause https://www.nutrition.org.uk/healthyliving/lifestages/teenagers.html Faculty of Science | Department of Biochemistry Eating Disorders in Adolescents (& Young Adults) (Chapter 9 Controversy) 85% of eating disorders start during adolescence Diagnosed ED occur predominantly in females, but males also afflicted Undiagnosed disordered eating is highly prevalent in young females and males ie, dissatisfaction with body size leads to dieting, restrictive eating behaviours, misuse of supplements, etc Societal pressures to be thin contribute to eating disorders, “…media convey the message that to be thin is to be happy; eating disorders are not a form of rebellion against these unrealistic ideals, but rather an exaggerated acceptance of them.” US National Association of Anorexia Nervosa and Associated Disorders estimates that 11% of high school students have a diagnosed eating disorder ‐‐ 20‐30% of those are boys. Faculty of Science | Department of Biochemistry Eating Disorders in Adolescents & Young Adults All eating disorders involve dissatisfaction with body weight Body image becomes central to the feeling of self‐worth Likely caused by a combination of sociocultural, psychological, genetic and neurochemical factors (note that ED do not exist outside of developed nations) Tend to occur in middle and high income families Dysfunctional family dynamics and parenting styles have been implicated Disagreement between parents on discipline, low expressions of affection, controlling, critical, values physical appearance Faculty of Science | Department of Biochemistry Eating Disorders in Adolescents & Young Adults Anorexia Nervosa – self starvation – high risk of death Mostly females, but ~5‐10% are males Low body weight is the (unreachable) goal, intense fear of gaining weight Self‐perception of body size becomes distorted, person cannot “see” that they have a very low body weight, despite physical signs of malnutrition Very self disciplined, extensive knowledge of calorie content of food, high water intake (or other non‐caloric beverages) Very little food intake, excessive exercise to compensate for calorie intake, laxative abuse to hasten movement of food through the GIT High risk for suicide Faculty of Science | Department of Biochemistry Eating Disorders in Adolescents & Young Adults Anorexia Nervosa – self starvation – high risk of death Malnutrition leads to: Halted growth in teenagers (permanent stunting may occur) Body fat then protein (muscle) loss, hair loss Impaired bone mineralization, anemia, fine hair growth (to preserve heat) Impaired intestinal function (protein turnover of cells impaired, digestive enzymes reduced, diarrhea may occur) Neurological changes (may worsen the psychological state) Electrolyte imbalance affects cardiac function Loss of cardiac muscle leads to death from heart failure Resistance to treatment because of inability to recognize the danger of the situation Faculty of Science | Department of Biochemistry Eating Disorders in Adolescents & Young Adults Bulimia Nervosa – binge and purge More prevalent than AN, difficult to detect in individuals Diagnostic criteria include Binge eating with inappropriate compensatory behaviours including self‐induced vomiting, abuse of laxatives, diuretics or other medications (emetics), fasting and excessive exercise Behaviours occur at least 1x per week for 3 months A sense of lack of control during the eating episode Binge eating episodes of >1000 Cal/binge, maybe multiple times a day Tends to be close to ideal body weight Generally doesn’t interfere with daily life “binge foods” characteristically high fat, high carb foods Shame and self‐disgust occurs because of awareness of the damaging nature of the behaviours (unlike AN) Faculty of Science | Department of Biochemistry Eating Disorders in Adolescents & Young Adults Bulimia Nervosa – binge and purge Chronic vomiting, emetics or laxative use may lead to: Physical damage to the GIT, including acid erosion of the esophagus (ulceration with risk of rupture), thinning of the muscle wall of the stomach with risk of rupture Electrolyte imbalances due to loss of electrolytes with vomit and diarrhea can lead to cardiac arrhythmias Damage to salivary glands, erosion of teeth due to acid Drugs used to induce vomiting (emetics) can also damage the heart Faculty of Science | Department of Biochemistry Eating Disorders in Adolescents & Young Adults Binge Eating Disorder – generally restrictive food intake, with occasional binging (no purging) The most “treatable” of the eating disorders Feelings of lack of control, shame, self‐disgust common to bulimia Considered to be common (half of “dieters” will binge; one third of obese people) Food intake during binges is less frequent than in bulimia, with lower overall food intake. Faculty of Science | Department of Biochemistry Eating Disorders in Athletes Male athletes with well‐muscled bodies see themselves as underweight and weak This distorted body image may lead to: Frequent weighing Excessive exercise Overuse of special diets or supplements Abuse of steroid drugs Male athletes under pressure to maintain a specific body weight or %body fat are also at risk for disordered eating or dangerous practices (skaters, dancers, divers, gymnasts, wrestlers, boxers, endurance runners) 45% of males with anorexia nervosa are involved in a sport or occupation where body weight is important for good performance A study of male phys ed undergraduate students in France identified disordered eating in 20% of the students (Filiaire et al 2012) References found at: 9-72 https://www.eatingdisorderhope.com/information/anorexia/male‐athletes Faculty of Science Department of Biochemistry Eating Disorders in Athletes – The Female Triad 3 associated medical problems: 1. Disordered eating 2. Amenorrhea 3. Osteoporosis Pressure to achieve very low body fat leads to low energy and nutrient intake Low body fat leads to amenorrhea (up to 66% of female athletes) Excessive weight‐bearing exercise in anorexia with amenorrhea will result in bone mineral loss Risks of stress factures in early life High risk of osteoporosis in later life Copyright © 2018 by Nelson Education Ltd. 9-73 Faculty of Science | Department of Biochemistry Faculty of Science | Department of Biochemistry