LECTURE OVERVIEW WHY DO WE EAT WHY DOES
- Slides: 14
LECTURE OVERVIEW WHY DO WE EAT? WHY DOES EATING BECOME DISORDERED? PSYCHOSOCIAL AND BIOLOGICAL FACTORS OBESITY, ANOREXIA, BULLIMIA ©John Wiley & Sons, Inc. 2010
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
Drive-Reduction Theory ©John Wiley & Sons, Inc. 2010
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
Hunger and Eating • Cannon & Washburn’s early technique for measuring internal factors in hunger ©John Wiley & Sons, Inc. 2010
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
Psychosocial Theories for why eating becomes disordered (cont. ) Behavioral: unhelpful learned associations Analytical: expression of inner conflict ©John Wiley & Sons, Inc. 2010
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 on the right had • the lateral hypo. removed. ©John Wiley & Sons, Inc. 2010
CHEMISTRY OF EATING? • Is the ventromedial • Ghrelin is the hormone hypothalamus a satiety that signals hunger in center? Is the lateral the brain. hypothalamus an eating center? • Leptin is the hormone that signals satiety in the brain. ©John Wiley & Sons, Inc. 2010
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
Is Obesity a Psychological Issue? • Obesity results from numerous biological and psychosocial factors. BMI > 30 ©John Wiley & Sons, Inc. 2010
• Anorexia nervosa & bulimia nervosa are both characterized by an overwhelming fear of becoming obese & explained by multiple biological & psychosocial factors. ©John Wiley & Sons, Inc. 2010
©John Wiley & Sons, Inc. 2010
©John Wiley & Sons, Inc. 2010
