FACT: In the U.S., obesity is most common among lower-income people. However, people who live on extremely low incomes seldom suffer from eating disorders.

FACT:

In the U.S., obesity is most common among lower-income people. However, people who live on extremely low incomes seldom suffer from eating disorders such as bulimia and anorexia nervosa.

WHY?

Hunger: The Greatest of All Motivators

What causes hunger? It’s more complicated than you’d think!

It does not only happen with stomach contractions and an empty stomach

People who have had their stomachs removed still feel hunger!

Biochemistry of hunger

How do you know when to stop eating?

Metabolism

The body is predisposed to maintain itself at a particular weight (set point); “weight thermostat”

The Psychology of Hunger Rozin (1998):

offered two patients with anterograde amnesia a lunch three times, twenty minutes apart- and they ate them all!

The point of the story:

External factors

Eating is a social experience.

We usually eat more when in the presence of others.

Hunger can be triggered more by the presence of food than by internal factors.

Rodin study (1984):

Stress, anxiety, and mood Carbohydrates

help boost the neurotransmitter serotonin, which has calming effects.

Taste preference

We are genetically wired to crave sweet, salty, and fatty foods, all of which are rare in nature.

America’s Battle of the Bulge

66% of Americans are overweight

Obesity rate has doubled for adults in 40 years;34% of American adults are obese (30% above one’s recommended weight); obesity rate for kids has quadrupled

25% of adults are on diets at any given time; most dieters eventually regain most or all of the lost weight

Why is it so hard to lose weight?

People gain fat by consuming more calories than they expend

A pound of fat = 3,500 calories

A typical adult has 30-40 billion fat cells

Obese people have about 75 billion fat cells and they may be 2-3 times their normal size

The number of fat cells never decreases, though they can shrink

Our unhealthy environment Sleep loss: Decreasing activity levels: Energy-saving technology: Commuting: Greater availability of cheap, processed junk

food high in calories, low in nutrition:

Eating disorders At the same time, rates of anorexia, bulimia, and

binge-eating disorders are increasing Over 50% of U.S. women feel negatively about

their appearance “An increasingly stringent cultural standard of

thinness for women has been accompanied by a steadily increasing incidence of serious eating disorders in women.” -Susan and Orland Woolsey (1983)

Those who watch TV 3 or more nights a week were 50% more likely to describe themselves as “too big or fat”

The island of Fiji: a case study about the impact of culture.

http://www.nytimes.com/1999/05/20/world/study-finds-tv-alters-fiji-girls-view-of-body.html?pagewanted=1

http://news.bbc.co.uk/2/hi/health/347637.stm

http://news.harvard.edu/gazette/story/2009/03/fijian-girls-succumb-to-western-dysmorphia/

What can we learn about the issue of cultural influence and media from this case study? What larger conclusions can be drawn about human nature?