[November 18, 2014]
PHYSIOLOGY OF HUNGER
Body chemistry
● genetic
● early childhood eating habits - bre feeding
○ when babies nurse vs. taking bottle, babies nursing can’t see how much they are taking in
○ bottle feeding shows exactly how much they are eating
○ by letting babies control how much they eat, habits and metabolic rate may be affected
○ lower rates of childhood obesity in breastfed babies
● different in men and women
● metabolisms
Brain
● hypothalamus
○ lateral region (brings on hunger)
■ if you stimulate this, even well fed animals will become hungry
○ ventromedial (depresses hunger)
■ if you stimulate this, not fed animals will still not be hungry
○ by stimulating one region, the opposite feeling
Body chemistry
Brain
● hypothalamus
○ lateral region (brings on hunger) “on center”
○ ventromedial (depresses hunger “off center”
Role of Ghrelin
● hormone increases before meals and decreases after meals
● linked to appetite
● EYY in mice
● leptin:
Set Point Hypothesis
● different people have set point or set weight that they gravitate back to if they gain or lose weight
● not fixed in stone because over the course of development we grow
○ in adulthood, it still changes slightly
● number of fat cells: generally when we lose weight, we don’t lose fat cells, they usually just get smaller
● when people lose weight, they often gain it back because of body chemistry and set point
External incentives
● the smell of food (ex. walking by a restaurant)
● the visual of food (ex. on TV)
● people more external about their food are not always aware of the internal signals (just ate, full stomach, don’t need to eat, etc.)
○ not sure about causes (biology, eating habits established over lifetime)
Taste preference (culture)
● we learn to like different foods
● as children, we are very reluctant to try new things
○ research: you need to try foods over 30x to actually like it
● ex. whale blubber, worms, etc.
OBESITY
Genetics and Heritability
● we’re genetically programmed to like sweets
● research: if you inject sweetener into amniotic fluid, fetuses will swallow it more
● we’re adapted to feast versus. famine conditions
● identical twin studies: weight correlates .75
○ genetics to play a role in obesity, but there is an environment component
Fat Cells
● hunt is on for chemicals and genes that contribute to hunger and obesity
● genetics to play a role in obesity, but there is an environment component
Culture Becker et al Fiji Adolescent Girls Study (2002)
● ideal beauty was a fatter type
● Western TV came to Fiji during the course of the study
● interviewed girls and gave them a particular (EAT:eating attitudes test)
● noticed dramatic increases in eating disorders post Western TV influence
, ● a study can’t be done like this in the United States because media exposure has become so embedded into our society
Stigma of Obesity
● as a culture we have a paradoxical thing going on with obesity and eating disorders
● obese children are viewed negatively by peers
○ research: children’s vote children heavier than average lower than those lighter. Noticed heavier girls more. Kids would say that
the heavier kids ate cake, poop, etc.
● gender and obesity
○ there’s always more of an impact on women: in comparison to heavier men, heavier women experience lower salaries, victims
of discrimination, less likely to marry, weightist condemnation
● trends in the US: as a culture we are getting heavier, there is an increase in diagnosis of eating disorders, there is an increase in weight-
related diseases and disorders
○ largest correlation to obesity is time spent watching TV
○ in children’s TV, there is a significant number of foods being exposed (ex. soda)
EATING DISORDERS
Anorexia Nervosa
● criteria: fear of becoming obese, disturbance of body image, weight loss of at least 25%, refusal to maintain a healthy body weight, no
physical illness that would account for weight loss
● 1/50 girls affected (only about 5-15% are boys). There are a good amount of girls who go undiagnosed as well.
● preadolescent girls
○ problem because sexual maturation cannot occur normally
○ there is a natural weight gain so that a sufficient amount of body fat and lactation is available in a girl in preparation for future
pregnancies
○ adolescent immortality: young girl believe they are invincible and can handle things like anorexia
● more common in: caucasian americans as opposed to african americans, those whose families have lived in America for more generations
● increase in anorexia around menopause
● about 4% of those with anorexia die due to physical complications with anorexia (highest death rate of eating disorders)
○ generally damage to heart muscle since losing body fat turns into losing muscle
● what role does the media play?
○ there exist websites that support and normalize the anorexia nervosa lifestyle and mentality
■ include thinspiration such as celebrities and models
● Kat’s story (https://www.youtube.com/watch?v=stH-LRTjEC0&index=6&list=PL5EEA5F2DFE55BB61)
○ devastating physical consequences (not all immediate): tired, weak, hair loss, toenail and fingernail weakening, major muscle
soreness due to a calcium deficiency, brittle bones, will inevitably have osteoporosis in the future, teeth are so rotten that she
needs to get them all pulled out surgically, impacted bowels because of a lack of fiber) that needed to be dealt with at a hospital
(enema), stomach acid in bowls, uncontrollable bladder, multiple kidney infections, iron deficiencies, heart attack
Bulimia
● criteria: episodic binge-purging, sometimes the use of laxatives, not being able to stop binging/purging voluntarily, depressed mood/self
deprecating thoughts/humiliation, repeated attempts following bingeing to control weight dieting that is followed by bingeing/purging,
● may not be underweight
● tissue damage in the throat: body is not designed to handle stomach acid coming up, this can lead to a precancerous condition called
Barrett's esophagus
● damage in teeth: turns a translucent due to loss of enamel
● UMich study: 19% of college age women exhibited symptoms of bulimia
● can be fatal (3.9%)
○ with bulimia, body chemistry gets completely out of whack
○ potassium problems and cardiac problems (arrhythmia, etc.)
Does society contribute to eating disorders?
● yes
LOVE [November 20, 2014]
LOVE
● there are individual differences with all kinds of love
John Alan Lee: multiple styles of love
● ludus: game playing love,the chase is fun, tends to not have much commitment
○ ex. chasing dragon to save the princess, what happens on the 3rd data (who calls who first)
● eros: intense physically passionate love, Shakespeare often talked about this kind
● storge: mutual romantic feelings
● mania: a love characterized by jealousy and intensity, it involves stalking
● pragma: practical love
○ ex. choosing someone who you believe will be a great parent