Food, Dieting, & Body Image

1. Food, Dieting, & Body Image Lecture 13 3/22/04

2. Clueless Clip

3. Why study eating and dieting? • 60% of Americans surveyed would like to lose weight • 1 out of every 3 Americans is on a diet • Americans spend ~$50 billion/year on weight loss including low calorie foods and beverages • 9 out of 10 formerly obese people would rather have a leg amputated than be obese again

4. Eating: What Motivates it? • Biology • Neural Structures • Psychology

5. Rumblings of Early Theories • Cannon & Washburn (1912) • Hunger at the height of contractions • BUT, removed stomachs & amnesics • Glucose Thermostat

6. Leptin • Recently discovered hormone produced by ob gene • Involved in fat regulation • Acts on hypothalamus to inhibit eating • Genetic deficiency can lead to obesity

7. Why else might we eat? • Taste, smell, vision, conditioning… • Sweetness • Mood (good, bad, stress) • Fatty foods (taste, smell, texture) • Variety • Time of day • Presence of others • “feminine”

8. Even rats regulate their weight poorly when given access to a variety of high calorie foods

9. Neural processing in eating • Hypothalamus: most influential brain structure • 1939: Tumors can cause massive obesity • Lesions to ventromedial hypothalamus (VMH) • Hyperphagia: excessive eating • To Lateral hypothalamus • Aphagia: dramatic reduction in eating • Orbitofrontal cortex • Processes taste cues in hungry animals • AND, Gourmand syndrome…

10. Gourmand Syndrome • Damage to right frontal lobe and limbic system • Obsessed with fine food and food preparation • 1st case, 1989 • “From political settings to table settings”

11. Health Conscious and… • Obesity • 33%, 2002 • 25% vs. 18% body fat [NOTE: these are averages for women and men] • Body Mass Index (BMI) >29 • Meanwhile… • Biological effects: diabetes, h. disease, respiratory, arthritis, depression, sleep apnea, cancer, DEATH • Social effects: Stigma (slow, lazy, sloppy, no willpower) & made less money, less likely to be married

13. Same Person, Same Story • Professional actors interview for job • SAME lines, intonation, gestures • Normal weight vs. Overweight (theatrical prosthesis) • P’s read job description, resume, then viewed videotaped interviews • Perceived more negatively (Non-productive, indecisive, unattractive, incompetent) • Less likely to be hired

14. Genes (can) & Environment (will) • 1,000 extra calories/day, 100 days • Some gained, some didn’t (4.3-13.3kg)! BUT… • Identical twins: • 60-80% heritability estimates for BMI • No difference between raised together and raised apart • Danish adoption study • BMI strongly related to biological parents • BMI unrelated to adoptive parents

15. Another Irony • With expanding waistlines, increasing idealization of thin and fit look • What shapes our ideal weight? • CULTURE: Jean Kilbourne

16. How do we know what to look like?

17. Distorted body perceptions • What are the effects of reading Cosmo, Glamour, Vogue…? • Magazines promote thinness and associate attractiveness with body weight • Models are underweight (87% vs. 11%) • Feature products and articles about getting thin • Body dissatisfaction, low self-esteem, guilt, shame, anxiety, depression, eating disorders… • Stice (2001): In a natural environment, • 219 girls (13-17) • 15 month subscription to Seventeen

18. Put this swimsuit on… • “Consumer choice study”

19. How were their scores?

20. Eating Disorders • Anorexia • Excessive fear of becoming fat, refuse to eat • ~1% of female adolescents • Despite severe emaciation, still believe not thin enough • 15-20% eventually die

21. Eating Disorders II • Bulimia • Marked by cycles of extreme binge eating followed by self-induced vomiting • ~4% of college-aged women • Believe eating is out of control, excessive worry about weight • Secretly compensate via vomiting, exercise, laxatives