Hunger and Motivation

Question 1

What was the initial hypothesis for what caused hunger? (washburn, cannon). What was the fatal flaw here?

Answer 1

that stomach contractions (grumbling) caused it. Hunger abounds even when stomachs removed

Question 2

Which part of the brain controls hunger? How is it divided? What was the misconception here?

Answer 2

Hypothalamus. Divided into:
Lateral hypothalamus (LH) (Hunger)
Ventromedial nucleus (satiety) 
Misconception: on/off switches. More just increases levels of each

Question 3

What did the removal of the LH and Ventromedial Nucleus do to rats?

Answer 3

LH: starved to death
N: ate until death

Question 4

What is the more correct theory about hunger control in the brain?

Answer 4

Arcuate nucleus and paraventricular nucleus are more important at controlling it. They contain neurons that detect hunger/fullness levels

Question 5

Generally, what’s wrong with the on/off switch theory?

Answer 5

Really should focus on interconnection of circuits instead

Question 6

Explain the Glucostatic theory. How does it leave room for alternative explanations?

Answer 6

When blood sugar/glucose drops, hormones are released that trigger hunger (like an empty tank light). Reason: glucose levels fluctuate very slowly

Question 7

How does the stomach itself regulate hunger?

Answer 7

Vagus Nerve: Cells in stomach send signals when they are expanded / stomach is full of food
Also cells that carry info on nutrients

Question 8

Describe the first two hormones that regulate hunger. What does one cause dumbass?

Answer 8

1. Ghrelin: excreted after long periods of no-food. Causes stomach contractions
2. CCK: excreted from upper intestine that sends satiety signals to brain

Question 9

Describe the NEXT two hormones that regulate hunger

Answer 9

3. Leptin: carries info about fat stores, regulates feelings of long term hunger
4. Insulin: from pancreas. extracts glucose from foods

Question 10

How does insulin and diabetes work?

Answer 10

Diabetics have trouble extracting sugar from foods which they need (because they don’t have insulin) so why they need snacks

Question 11

How does Ghrelin work against diets?

Answer 11

endoindocrine cells that are highest before meals (triggering hunger). But also slows metabolism. This results in you always wanting to eat, and being less able to burn fat when you do

Question 12

What are the three key environmental factors for regulating hunger?

Answer 12

1. availability of food
2. Learned preferences and habits
3. stress

Question 13

Explain the first two food-availability related cues and how one relates to buffets

Answer 13

1. Palatability: better food, will eat more of it

2. Quantity available: bigger portion sizes, will eat more. Also called bin model/heuristic

Question 14

What did that study about buffets revealed?

Answer 14

When bigger plates were offered, people ate 45% more and wasted 125% more

Question 15

What are the next three food-availability related factors for regulating hunger?

Answer 15

3. Variety: if there are fewer types of food, you will eat less because they will become less palatable more quickly
4. Presence of others: generally eat more when with people, especially lots of people, but not on dates
5. Stress: makes you crave fatty, sugary foods

Question 16

Names some environmental cues that also cause hunger

Answer 16

Ads, smells, kitchen

Question 17

Though food consumption varies across cultures, what is one innate taste we have?

Answer 17

Kids all love sweet things

Question 18

How are taste preferences formed?

Answer 18

Classical conditioning: association of food with good things

Question 19

Give an example of how habits and culture impact eating

Answer 19

Though we CAN eat lunch whenever we want now, we’re still eating at around 12-1 (learned habit)

Question 20

What is the relationship between the brain and sweet/fatty foods? What has brain imaging revealed?

Answer 20

That Limbic system (pleasure centre) is very active when consuming these. Mass release of dopamine

Question 21

What might one biological condition of food addiction be?

Answer 21

People may have different ways of processing dopamine levels/rewards

Question 22

Explain set point theory

Answer 22

We have a set point of weight that our body fights to maintain. Easier to gain/preserve weight then lose it

Question 23

What about settling point theory? What is this influenced by?

Answer 23

Set weight within a range that is influenced by genetics, culture, exercise, etc

Question 24

How is BMI calculated? What is obesity level bmi?

Answer 24

Body Mass Index: W/H/\2 >30

Question 25

What are the NA rates for OW and obese people? What are some issues causing this?

Answer 25

OB: 20%
OW: 40%
New access to high calorie foods, paired with less exercise, mobility, especially in kids/teens. Evil food industry

Question 26

What demographic are especially at risk for obesity in regards to kids?

Answer 26

Girls aged 12-17

Question 27

Explain the genetics behind obesity

Answer 27

Twins had a higher link (50%) of both being obese than fraternal. 61% of men and 73% of women’s weight propensity comes from genes. Inherent a VULNERABILITY to obesity

Question 28

Why are diets a bad idea?

Answer 28

Always hungry, so more likely to cave in. Fallacy that they are always on a diet or the exact opposite, when you can actually just regulate food

Question 29

What are two more impacts of social settings?

Answer 29

Modelling: Gaging what to eat based on others
Hospitality: hosts want you to eat more

Question 30

Most Obese country?

Answer 30

Nauru? pop 9900, 85% of men are obese. Massive amount of western food, 95% OW. half diabetic, were H/G.