Health PSYCHOLOGY
Eating, Nutrition,
Weight management,
and Obesity
“[People] dig their graves with
their own teeth and die more by
those fatal instruments than the
weapons of their enemies.”
-- Thomas Moffett, 1600
Food and Wellness
(Psychological and Physical)
 “What to eat” (M. Nestle)
 “Positive eating”
 “In defense of food” (M. Pollan)
 USDA’s MY Pyramid vs. Healthy Eating
Pyramid (Harvard)
 Slow food, fast food, no food, ???
WHAT’S A PERSON TO DO??!!!
Food and Wellness
(Psychological and Physical)
Nutrition and Wellness
Eating to feel well (as opposed to simply
getting calories) -- mens sana in
corpore sano
 Eating for psychological and physiological
wellness
 Eating for disease prevention
 Eating for _________________ (lots of
reasons)
What we eat
Macronutrients
Carbohydrates
Fats
Proteins
Micronutrients
Vitamins
Minerals
Phytochemicals
What we eat
Vitamins
 13 known vitamins, classified as either fat-soluble
(A, D, E, K) or water-soluble (B and C)
 C & E are antioxidants
Minerals
 Inorganic elements (e.g., calcium -- for muscle
contractions, nerve transmission)
Phytochemicals
 Bioactive chemicals found in plants (e.g., sterols,
flavonoids, beta-carotene) with potential healthpromoting qualities (e.g., anti-oxidant activity)
How we eat
Michael Pollan
NYTimes article (quiz)
Eat food
Mostly plants
Not too much
Impact of diet on:
Heart Disease
Cancer
Other Conditions
Weight Management
Caloric needs
Vary by age, sex, height, weight, activity level, &
basal metabolic rate (BMR)
Rough guideline (men = 2500 kcal, women =
2000 kcal)
Regular physical activity
ENERGY IN
ENERGY OUT
BODY MASS
GENES
Assessing body composition
Bioelectrical impedance — determining
body fat percentage by analyzing electrical
resistance (fat is a poor conductor)
Hydrostatic weighing — comparing
underwater weight with dry weight
Body mass index (BMI) – calculating a ratio
of height to weight
Calculating BMI
http://www.nhlbisupport.com/bmi/
BMI Categories:
Underweight = <18.5
Normal weight = 18.5-24.9
Overweight = 25-29.9
Obesity = BMI of 30 or greater
When we eat too much…
or move too little
Obesity (particularly “apple-pattern”)
linked to atherosclerosis, hypertension,
diabetes
Increased risk of several cancers, sleep
disturbances, degenerative joint disease
Impact on psychological well-being
Increased mortality rates (next slide)
Relationship between BMI and
Mortality
Factors That Contribute
to Obesity
Heredity / biological factors
Cultural factors
Emotional / behavioral factors
Hypothalamus and eating
Lateral Hypothalamus (LH)
Stimulation leads to hunger
Lesioning leads to self-starvation
Ventromedial Hypothalamus (VMH)
VMH lesioning leads to hunger
VMH stimulation causes an animal to
stop eating
Metabolism and weight
Basal Metabolic Rate (BMR)
base rate of energy expenditure
influenced by heredity, age, activity level, and
body composition (fat tissue has a lower
metabolic rate)
Set Point
the point at which an individual’s “weight
thermostat” is supposedly set
when the body falls below this weight, an
increase in hunger and a lowered metabolic
rate may act to restore the lost weight
“Is it genetic?”
ob gene
Regulates production of leptin
Leptin is secreted by fat cells and has dual
activity of decreasing food intake and
increasing metabolic rate
Mice born without the ability to make leptin
(ob/ob mice) eat without restraint
ob/ob mouse
normal mice
ob/ob mouse
ob/ob mouse
ob/ob mouse
injected with
leptin
So, just give obese
humans leptin!!!
In fact, this works in leptin-deficient
humans, but…
99.99% of obese humans have HIGH
levels of leptin, but have become
insensitive to it.
Hereditary factors
The genetic contribution to body weight is
estimated to be between 40 and 70 percent
(with some rare cases of severe obesity
linked to specific gene errors)
 Body weights of adopted children correlate
more strongly with weights of biological
parents
The epigenetics of increasing weight through
the generations (“One hypothesis is that maternal
obesity before and during pregnancy affects the
establishment of body weight regulatory mechanisms
in her baby. Maternal obesity could promote obesity
in the next generation." (Waterland, 2008)
Obesity Trends
 http://www.cdc.gov/nccdphp/dnpa/obesity/trend/maps/index.htm
Go to other PP slide show
Will the trend continue?
“Most adults in the U.S. will be overweight or
obese by 2030, with related health care
spending projected to be as much as $956.9
billion, according to researchers at Johns
Hopkins (July 2008, online issue of Obesity).
Obesity Trends
Why?
Factors That Contribute
to Obesity
Heredity / biological factors
Cultural factors
Emotional / behavioral factors
10,000 years ago –
who survived during a famine?
ENERGY IN
ENERGY OUT
Increase in
availability of
high density foods
(sugar/fat are cheap)
Decrease in workrelated activities
Decrease in activity
of daily living
Increase in size
Decrease in cost
BODY MASS
Genetic predisposition to store fat
Just as
our jeans no longer fit our waist,
our genes no longer fit our environment
Social/Cultural Factors
in Obesity
We live in a toxic environment. It’s like trying to
treat an alcoholic in a town where there’s a bar every
ten feet. Bad food is cheap, heavily promoted, and
engineered to taste good. Healthy food is hard to
get, not promoted, and expensive.
If you came down from Mars and saw all this, what
else would you predict except an obesity epidemic?
Kelly Brownell, Yale, 2004 (Nat’l Geo. Article: The heavy cost of fat)
Social/Cultural Factors
in Obesity
Food-toxic environment (cheap, hi-cal, lo-quality
food available)
 Absence of supermarkets in lo-income
neighborhoods
 Way too many of our calories are coming from junk
food (and in the car). (Sugar: 172 lbs/pp per year)
 Governmental contribution (ABC News video):
dependence on Zea Mays (a giant tropical grass)
 We are simply eating more! (next slide)
Humongasize it!!
Past
Today
French Fries
2.4 oz
210 kcal
(1955)
7 oz
610 kcal
Soda
6.5 oz
79 kcal
(1916)
20.0 oz
250 kcal
Hershey’s Bar
2 oz
300 kcal
(1900)
7 oz
1000 kcal
POPCORN
20 Years Ago
270 calories
5 cups
Today
1700 calories
21 cups buttered
Social/Cultural Factors
in Obesity
Pounds consumed per person
1970 – 1,497 lbs.
2000 – 1,775 lbs.
•2004: The "Monster
Thickburger" — two 1/3pound slabs of Angus beef,
four strips of bacon, three
slices of cheese and
mayonnaise on a buttered
sesame seed bun
•1420 calories!
Social/Cultural Factors
in Obesity
Cultural variation in ideal body image
(overemphasis on thinness  yo-yo
dieting and eventual weight gain)
Japanese-American men are 3 times as
likely to be obese as men living in Japan
Pima Indians (next slide)
Social/Cultural Factors
in Obesity
Pima Indians (in Mexico vs. in U.S.)
Emotional / behavioral
factors
Disinhibition — overeating triggered by an
event, emotion, or behavior
Eating used as coping
Internality / Externality hypothesis
Sensitivity to cues
Overweight people often more sensitive to external:
Time of day
Commercials
“Golden arches”
Dieting concerns
Dieting
In U.S., 72% of women and 44% of men
have dieted at some point in their adult lives
Yo-yo dieting associated with progressive wt
gain
Chronic dieting influence BMR negatively
Fad diets and health problems
Trend is improving, with fewer people on
“diets” these days
Healthy Weight Loss
Cognitive-behavioral program
Goal-setting, monitoring, social support
L.E.A.N.
Lifestyle changes (stimulus control, selfmonitoring, speed, etc.)
Exercise
Attitude
Nutrition
Stepped
Care for
Obesity