Mod. 38 – Hunger Motivation (p.396-405)

Motivation of HUNGER

Biological Basis of Hunger Hunger does NOT come from our stomach. The Hypothalamus

Ventromedial Hypothalamus Lateral Hypothalamus Ventromedial Hypothalamus When stimulated it makes you hungry. When lesioned (destroyed) you will never be hungry again. When stimulated you feel full. When lesioned you will never feel full again.

Set Point Theory hypothalamus acts like a thermostat- to maintain a stable weight (set point weight) When we drop below that set point weight (when your dieting), the hypothalamus, says for you to eat more, lowers your metabolic rate Activate the lateral hypothalamus when you diet Activate the ventromedial hypothalamus when you start to gain weight. Metabolic rate- how quickly your body uses energy

Leptin Theory Leptin- protein hormone secreted by fat cells Too much leptin causes brain to increase metabolism and decrease hunger LePTin L= Lard (fat) PT = ProTein

Body Chemistry Glucose- blood sugar Insulin- hormone secreted by pancreas, controls blood glucose The hormone insulin converts glucose to fat. When glucose levels drop (hypoglycemic)- hunger increases.

Hunger Hormones: Insulin- secreted by pancreas, controls blood glucose Grehlin- hormone secreted by empty stomach, sends “I’m hungry” signals to brain…. “my stomach is a grehlin, I’m hungry.” Orexin- secreted by hypothalamus, makes you hungry… “T-orexin search for food.” Leptin- protein hormone, secreted by fat cells, too much = metabolism increases, hunger decreases PYY- digestive tract hormone, sends “I’m not hungry” signals to brain…..

Textbook Notes: Physiology of Hunger:

The Physiology of Hunger Contractions of the stomach Washburn study

The Physiology of Hunger Body Chemistry and the Brain Glucose Insulin Hypothalamus Lateral hypothalamus orexin Vetromedial hypothalamus

The Physiology of Hunger Body Chemistry and the Brain Appetite hormones Ghrelin Obestatin PYY Leptin Set point Basal metabolic rate

Psychological Aspects of Hunger Externals v. Internals Externals: stress, smells, food being in front of you Internals: motivated by internal cues, empty stomach, feelings of hunger We’re a mix of both The Garcia Effect/ Garcia’s Taste Aversion- classical conditioning, you become sick (UR) after eating spoiled oysters (UCS), you wont eat them again, you avoid all oysters (CS)

Taste Preferences: Biology & Culture: Tense/depressed/Stressed crave carbs (starchy, carb foods)…. Carbs boost serotonin = calming effect (“Serotonin flavored mash potatoes ” “Serotonin flavored ice cream”). Sweet & salty- genetic & universal Cultural preferences- ewww dog meat! Dairy producing cultures (milk) more people are lactose tolerance Hot climates- spicy foods- spices keep food from spoiling Neophobia- dislike of unfamiliar things

Culture and Hunger

Dog Mice Wine Fried Frog Legs Criadillas- bull testicles.

Eating Disorders DSM-V : Diagnostic & Statistical Manual for Mental Disorders; classifies, categorizes disorders, symptoms, describes & defines, NO CAUSES, NO TREATMENT Disorder UMAD? Unjustifiable Maladaptive (harmful) Atypical Disturbing (disrupts functioning) Feeding & Eating Disorders: Anorexia Nervosa Bulimia Nervosa Binge Eating Disorder- binging, uncontrollable , distressed/upset after the binge Pica- eating nonedible things, like the couch, bricks, hair

Anorexia Nervosa Starve themselves to below 85% of their normal body weight. See themselves as fat, preoccupied w/food Vast majority are woman (9/10) Develops in adolescence Family= competitive, high achieving, protective Beings with a weight loss diet Click on the woman to watch a case study of an anorexic.

Bulimia Nervosa Characterized by binging (eating large amounts of food at once) and purging (getting rid of the food: vomiting, laxatives, excessive exercise). More common than anorexia Mostly women in their late teens, early 20s Preoccupied w/food, fearful of becoming overweight, depressed, anxious Weight fluctuates w/in and above normal ranges Family = alcoholism, obesity, depression Begins after a restricted diet has been broken

Eating disorders (Anorexia & Bulimia) … Mothers tend to be focused on their own weight, and also on daughter’s weight & appearance Mostly women in weight conscious cultures In British study: men more likely to be overweight; women more likely to perceive themselves as overweight

Textbook Notes: Psychology of Hunger:

The Psychology of Hunger Taste Preferences: Biology and Culture Genetic: sweet and salty Neophobia Adaptive taste preferences

The Psychology of Hunger Eating Disorders Anorexia nervosa Bulimia nervosa Binge-eating disorder

Level of Analysis for Our Hunger Motivation

Level of Analysis for Our Hunger Motivation

Level of Analysis for Our Hunger Motivation

Level of Analysis for Our Hunger Motivation

Obesity Severely overweight to the point where it causes health issues. Mostly eating habits but some people are predisposed towards obesity. Click on the pictures to see some case studies on obesity.

Textbook Notes: Obesity:

Obesity and Weight Control Historical explanations for obesity Obesity Definition Statistics Obesity and life expectancy

Obesity

Obesity

Obesity and Weight Control The Social Effects of Obesity Weight discrimination Psychological effects of obesity

Weight Discrimination

Weight Discrimination

Obesity and Weight Control The Physiology of Obesity Fat Cells

Obesity and Weight Control The Physiology of Obesity Set point and metabolism

Obesity and Weight Control The Physiology of Obesity The genetic factor The food and activity factor Sleep loss Social influence Food consumption and activity level

Obesity and Weight Control Losing Weight Realistic and moderate goals Success stories Attitudinal changes

Crash Course Review Book 2nd Ed.: OBESITY

Obesity: (Notes from Crash Course Review Book 2nd Ed.) 2/3 USA adults = overweight ½ of that group = obese 1/6 USA kids (6-19 yrs old) = overweight Obesity  heart disease, diabetes, kidney failure, cancers 300K USA adult deaths attributable to obesity

Obesity: (Notes from Crash Course Review Book 2nd Ed.) Factors in becoming overweight & obese: Environment: abundant, easily obtainable high-fat, high-calorie foods: in last 20 yrs, avg. daily caloric intake has increased 10% (men) & 7% (women) USA sedentary lifestyle: 4/10 never exercise Lack of adequate sleep  increases production of ghrelin (appetite-increasing hormone) & decreases production of leptin (appetite- suppressing hormone) Genetic predispositions to obesity: people w/family history of obesity are 2-3X more likely to be obese