8 - hunger, eating and health

Question 1

the human digestive system

Answer 1

1. mouth and salivary glands
2. oesophagus
3. stomach
4. liver/gall bladder
5. pancreas
6. small intestine

Question 2

what does the pancreas do?

Answer 2

produces insulin and glucagon to store and release energy

Question 3

what does the small intestine do?

Answer 3

absorbs most nutrients from the food that we eat

Question 4

what does the large intestine do?

Answer 4

removes water and packs waste

Question 5

what do liver and kidneys do?

Answer 5

filter out toxins for excretion

Question 6

what does glucagon do?

Answer 6

shifts ‘fuel’ from storage to where it is needed in the body

converts glycogen and proteins to carbohydrates

frees fat stores to use as fuel when the glucose stores are low

Question 7

what does insulin do?

Answer 7

shifts carbohydrate from blood to storage (glycogen, proteins)

Question 8

what do the liver and gall bladder do?

Question 9

what are the three core products of digestion?

Answer 9

• lipids/fats
• amino acids
• glucose

Question 10

what are the storage mechanisms of lipids/fats?

Answer 10

fats
largest and most efficient energy store

Question 11

what area the storage mechanisms of amino acids?

Answer 11

proteins
mostly in the form of muscle tissue

Question 12

what are the storage mechanisms of glucose?

Answer 12

glycogen
stored in muscles and liver
fast release

Question 13

how do we ensure that our food needs are met?

Answer 13

• homeostasis/set point theory
• hunger
• craving

Question 14

what are the mechanisms that make sure we eat when necessary?

Answer 14

• brain is sensitive to shortage of glucose
• liver is sensitive to shortages of glucose and lipids
• stomach sends signals to the brain if its unstimulated

Question 15

how does homeostasis/set point theory make sure we eat when necessary?

Answer 15

• hunger (motivational state): due to low levels of fatty acids/glucose
• craving (automatic behavioural state)

body corrects by:
- releasing glucose
- taking in more food

Question 16

what are short-term satiety signals?

Answer 16

• adequate glucose and lipid acid levels
• stomach distension (stretched)
• buccal activity (chewing)
• high levels of sensory stimulation (taste & smell)
• appetite suppressant chemicals (caffeine, amphetamines)

Question 17

what does fat tissue secrete?

Answer 17

hormone - leptin
- increases body metabolic rate
- decreases food intake by
- desensitising brain to hunger signals
- inhibits effect of other humans that drive eating (neuropeptide Y)

Question 18

what are long-term satiety signals?

Answer 18

• increased levels of leptin

Answer 19

ghrelin
neuropeptide Y

Question 20

what is the Minnesota starvation experiment?

Answer 20

join the army or take part in experiment
- studied the effects of starvation on 35 men
- cognitive, socially, emotional affects of starvation and weight gain

Question 21

how has the health implication of poor eating been studied?

Answer 21

• Minnesota starvation experiment
• dutch hunger winter

Question 21

what are the health implication of poor eating?

Answer 21

• nutritional deficits
• starvation effects can be immediate/long term (emotional instability, concentration, social, development, physical systems)
• starvation effects can cross generations e.g. obesity in the children of starved mothers

Question 22

what are the implications of obesity?

Answer 22

• affects multiple systems including social functioning
• premature mortality
• specific problems in children (bullying, self-esteem)

Question 23

what factors take us away from homeostasis?

Answer 23

• genetics
• learning
• social pressures
• food industry
• toxic environment

Question 24

how do genetics effect what we eat?

Answer 24

make us more likely to like particular foods

we are predisposed to high-energy, high-taste foods as they are more likely to contain nutrients
- sweet
- fatty
- salty

avoid bitter foods as they are associated with toxicity

Question 25

how are tase preferences and aversions learned?

Answer 25

• culture
• upbringing
• satiety to specific foods “I don’t want pizza, we had it yesterday”

Question 26

how does social learning effect eating?

Answer 26

imitation of what and how others eat
- types of food
- specific foods
- speed of eating
- amount eaten
this can be powerful cultural influence

Question 27

how do environmental factors effect eating?

Answer 27

• eat more in dim lighting
• eat more when cold
• portion sizes
• smells of food and environment
• location/proximity of foods

Question 28

how does agriculture and food industry effect eating?

Answer 28

• selling processed food that is relatively cheap
• in large quantities
• ensure profit margins
• fatty and sugary foods
  premium prices on healthy foods

Question 29

what are side effects of high fructose corn syrup?

Answer 29

• fatty liver
• decreased insulin sensitivity
• gout precursors