1. LECTURE OVERVIEW WHY DO WE EAT? WHY DOES EATING BECOME DISORDERED? PSYCHOSOCIAL AND BIOLOGICAL FACTORS OBESITY, ANOREXIA, BULLIMIA ©John Wiley & Sons, Inc. 2010

2. Why is eating so complicated? Eating is a motivated behavior, yet it is also confused with emotion and can become disordered. ©John Wiley & Sons, Inc. 2010

3. Drive-Reduction Theory ©John Wiley & Sons, Inc. 2010

4. 1.Eating to reduce hunger is a good example of the drive theory of motivation. 2.But the arousal theory of motivation explains why we might eat a slice of pumpkin pie after consuming a heavy holiday dinner i.e. stimulation seeking. ©John Wiley & Sons, Inc. 2010

5. Cannon & Washburn’s early technique for measuring internal factors in hunger ©John Wiley & Sons, Inc. 2010 Hunger and Eating

6. Psychosocial Theories for why eating becomes disordered Incentive: motivation results from the “pull” of external environmental stimuli Cognitive: motivation affected by attributions & expectations. ©John Wiley & S

7. Psychosocial Theories for why eating becomes disordered (cont.) Behavioral: unhelpful learned associations Analytical: expression of inner conflict ©John Wiley & Sons, Inc. 2010

8. Hunger and Eating Biological factors: stomach, biochemistry, the brain Note the size difference in these rats. The rat on the left had the ventromedial area of its hypothalamus destroyed, the one on the right had the lateral hypo. removed. ©John Wiley & Sons, Inc. 2010

9. CHEMISTRY OF EATING? Is the ventromedial hypothalamus a satiety center? Is the lateral hypothalamus an eating center? Leptin is the hormone that signals satiety in the brain. Ghrelin is the hormone that signals hunger in the brain. ©John Wiley & Sons, Inc. 2010

10. Hunger and Eating Psychological factors: visual cues, cultural conditioning Or Genetic: Obesity is more common in Pima Indians living in U.S., but not for those in nearby Mexico with traditional diet. ©John Wiley & Sons, Inc. 2010

11. Is Obesity a Psychological Issue? Obesity results from numerous biological and psychosocial factors. BMI > 30 ©John Wiley & Sons, Inc. 2010

12. Anorexia nervosa & bulimia nervosa are both characterized by an overwhelming fear of becoming obese & explained by multiple biological & psychosocial factors.

13. ©John Wiley & Sons, Inc. 2010