1. Physiology of Hunger Glucose= blood sugar Glucose= blood sugar Pancreas produces insulin / breaks down glucose (converts some to stored fat) Pancreas produces insulin / breaks down glucose (converts some to stored fat) Stomach, liver, intestines: signal brain as to glucose level Stomach, liver, intestines: signal brain as to glucose level

2. Hypothalamus Part of Limbic System Part of Limbic System Helps govern endocrine system (regulates pituitary gland) Helps govern endocrine system (regulates pituitary gland) Linked to emotion Linked to emotion Drives: eating, drinking, body temp. Drives: eating, drinking, body temp. Monitors levels of body’s appetite hormones Monitors levels of body’s appetite hormones

3. Lateral Hypothalamus Stimulates hunger Stimulates hunger rat research rat research  Stimulate: Continuous eating to obesity  Destroy: Starving would not eat

4. Lower-mid hypothalamus (Ventromedial) Depresses hunger Depresses hunger Stimulation = stop eating Stimulation = stop eating Destroy it = obesity (no brakes) Destroy it = obesity (no brakes)

6. Hormones / Chemicals and Hunger… Ghrelin: hormone secreted by empty stomach (arouses hunger) Ghrelin: hormone secreted by empty stomach (arouses hunger) Gastric bypass surgery = less ghrelin Gastric bypass surgery = less ghrelin Orexin: stimulates hunger (activated by low glucose) Orexin: stimulates hunger (activated by low glucose) Leptin: chemical secreted by fat cells Leptin: chemical secreted by fat cells  suppresses hunger PYY: Digestive hormone / suppresses hunger PYY: Digestive hormone / suppresses hunger Research to address obesity Research to address obesity

8. Theories on Hunger and Body Weight Set Point: (weight thermostat) Set Point: (weight thermostat)  Body adjusts to changes in food intake to maintain homeostasis (has a general, preset tendancy to maintain a certain body weight)  Less food = rise in hunger, fall in energy  9 month study: ½ food intake, 25% set point  Set point outdated / “settling point” Basal metabolic rate: energy expenditure at rest (metabolism) Basal metabolic rate: energy expenditure at rest (metabolism)

9. Hunger Motivation

10. Eating Disorders Anorexia Nervosa Obsession with losing weight (15% or more) Obsession with losing weight (15% or more) Starts with weight-lost diet Starts with weight-lost diet Negative self-body image / perfectionist standards Negative self-body image / perfectionist standards Usually adolescents Usually adolescents Mothers who focus on own weight Mothers who focus on own weight Competitive, high-achieving families Competitive, high-achieving families 9 of 10: female 9 of 10: female Genetic and cultural theories Genetic and cultural theories

11. Eating Disorders Bulimia Nervosa Bulimia Nervosa Binge-Purge Binge-Purge Overeating, compensatory vomiting, laxative use, fasting, extreme exercise Overeating, compensatory vomiting, laxative use, fasting, extreme exercise Dieter breaks diet restrictions… Dieter breaks diet restrictions… weight fluctuations within or above normal ranges (easy to hide) weight fluctuations within or above normal ranges (easy to hide) Often sweet, high fat foods Often sweet, high fat foods Depression, anxiety Depression, anxiety ½ of anorexia victims have bulimia symptoms ½ of anorexia victims have bulimia symptoms

12. Anorexia, Bulimia

13. The Ideal of Slenderness Distorting Reality

14. Obesity