Food, Food, Dieting, Dieting, & Body & Body ImageImage

Lecture 13Lecture 13

3/22/043/22/04

Clueless ClipClueless Clip

Why study eating and dieting?Why study eating and dieting?

60% of Americans surveyed would like to lose 60% of Americans surveyed would like to lose weightweight

1 out of every 3 Americans is on a diet1 out of every 3 Americans is on a diet

Americans spend ~$50 billion/year on weight loss Americans spend ~$50 billion/year on weight loss including low calorie foods and beveragesincluding low calorie foods and beverages

9 out of 10 formerly obese people would rather have 9 out of 10 formerly obese people would rather have a leg amputated than be obese againa leg amputated than be obese again

Eating: What Motivates it?Eating: What Motivates it? BiologyBiology

Neural StructuresNeural Structures

PsychologyPsychology

Rumblings of Early TheoriesRumblings of Early Theories

Cannon & Washburn (1912)Cannon & Washburn (1912) Hunger at the height of contractionsHunger at the height of contractions

BUT, removed stomachs & amnesicsBUT, removed stomachs & amnesics

Glucose ThermostatGlucose Thermostat

LeptinLeptin

Recently discovered hormone produced by ob Recently discovered hormone produced by ob genegene Involved in fat regulationInvolved in fat regulation Acts on hypothalamus to inhibit eatingActs on hypothalamus to inhibit eating Genetic deficiency can lead to obesityGenetic deficiency can lead to obesity

Why else might we eat?Why else might we eat?

Taste, smell, vision, conditioning…Taste, smell, vision, conditioning… SweetnessSweetness Mood (good, bad, stress)Mood (good, bad, stress) Fatty foods (taste, smell, texture)Fatty foods (taste, smell, texture) VarietyVariety Time of day Time of day Presence of othersPresence of others

““feminine”feminine”

Even rats regulate their weight poorly Even rats regulate their weight poorly when given access to a variety of when given access to a variety of

high calorie foodshigh calorie foods

Neural processing in eatingNeural processing in eating Hypothalamus: most influential brain structureHypothalamus: most influential brain structure

1939: Tumors can cause massive obesity1939: Tumors can cause massive obesity Lesions to ventromedial hypothalamus (VMH)Lesions to ventromedial hypothalamus (VMH)

Hyperphagia: excessive eatingHyperphagia: excessive eating To Lateral hypothalamusTo Lateral hypothalamus

Aphagia: dramatic reduction in eatingAphagia: dramatic reduction in eating

Orbitofrontal cortexOrbitofrontal cortex Processes taste cues in hungry animalsProcesses taste cues in hungry animals

AND, Gourmand syndrome…AND, Gourmand syndrome…

Gourmand SyndromeGourmand Syndrome

Damage to right frontal Damage to right frontal lobe and limbic systemlobe and limbic system

Obsessed with fine food Obsessed with fine food and food preparationand food preparation

11stst case, 1989 case, 1989

““From political settings toFrom political settings to table settings table settings””

Health Conscious and…Health Conscious and…

ObesityObesity 33%, 200233%, 2002

25% vs. 18% body fat 25% vs. 18% body fat [NOTE: these are averages for women and men][NOTE: these are averages for women and men] Body Mass Index (BMI) >29Body Mass Index (BMI) >29

Meanwhile…Meanwhile… Biological effectsBiological effects: diabetes, h. disease, respiratory, : diabetes, h. disease, respiratory,

arthritis, depression, sleep apnea, cancer, DEATHarthritis, depression, sleep apnea, cancer, DEATH Social effectsSocial effects: Stigma (slow, lazy, sloppy, no willpower) : Stigma (slow, lazy, sloppy, no willpower)

& made less money, less likely to be married& made less money, less likely to be married

Same Person, Same StorySame Person, Same Story

Professional actors interview for jobProfessional actors interview for job SAME lines, intonation, gestures SAME lines, intonation, gestures

Normal weight vs. Overweight (theatrical Normal weight vs. Overweight (theatrical prosthesis)prosthesis)

P’s read job description, resume, then viewed P’s read job description, resume, then viewed videotaped interviewsvideotaped interviews

Perceived more negatively (Non-productive, Perceived more negatively (Non-productive, indecisive, unattractive, incompetent)indecisive, unattractive, incompetent)

Less likely to be hiredLess likely to be hired

Genes (can) & Environment (will)Genes (can) & Environment (will)

1,000 extra calories/day, 100 days1,000 extra calories/day, 100 days Some gained, some didn’t (4.3-13.3kg)! BUT…Some gained, some didn’t (4.3-13.3kg)! BUT…

Identical twins: Identical twins: 60-80% heritability estimates for BMI60-80% heritability estimates for BMI No difference between raised together and raised No difference between raised together and raised

apartapart Danish adoption studyDanish adoption study

BMI strongly related to biological parentsBMI strongly related to biological parents BMI unrelated to adoptive parentsBMI unrelated to adoptive parents

Another IronyAnother Irony

With expanding waistlines, increasing With expanding waistlines, increasing idealization of thin and fit lookidealization of thin and fit look

What shapes our ideal weight?What shapes our ideal weight? CULTURE: Jean KilbourneCULTURE: Jean Kilbourne

Average Barbie Store

Height  5' 4"  6' 0"  6' 0"

Weight 145 101 NA

Bust 36.5 39 34

Dress 11-14 4 6

Waist 30 19 23

Hips 41 33 34

How do we know what to look like?How do we know what to look like?

Distorted body perceptionsDistorted body perceptions

What are the effects of reading Cosmo, Glamour, Vogue…?What are the effects of reading Cosmo, Glamour, Vogue…? Magazines promote thinness and associate attractiveness Magazines promote thinness and associate attractiveness

with body weightwith body weight Models are underweight (87% vs. 11%)Models are underweight (87% vs. 11%) Feature products and articles about getting thinFeature products and articles about getting thin

Body dissatisfaction, low self-esteem, guilt, shame, anxiety, Body dissatisfaction, low self-esteem, guilt, shame, anxiety, depression, eating disorders…depression, eating disorders…

Stice (2001): In a natural environment, Stice (2001): In a natural environment, 219 girls (13-17)219 girls (13-17) 15 month subscription to Seventeen15 month subscription to Seventeen

Put this swimsuit on…Put this swimsuit on…

““Consumer choice study”Consumer choice study”

How were their scores?How were their scores?

0

1

2

3

4

5

6

MEN WOMEN

SweaterSwimsuit

Eating DisordersEating Disorders

AnorexiaAnorexia Excessive fear of becoming fat, Excessive fear of becoming fat,

refuse to eatrefuse to eat

~1% of female adolescents~1% of female adolescents

Despite severe emaciation, still Despite severe emaciation, still believe not thin enoughbelieve not thin enough

15-20% eventually die15-20% eventually die

Eating Disorders IIEating Disorders II

Bulimia Bulimia Marked by cycles of Marked by cycles of

extreme binge eating extreme binge eating followed by self-induced followed by self-induced vomitingvomiting

~4% of college-aged ~4% of college-aged womenwomen

Believe eating is out of Believe eating is out of control, excessive worry control, excessive worry about weightabout weight

Secretly compensate via Secretly compensate via vomiting, exercise, laxativesvomiting, exercise, laxatives