Eating behaviour Flashcards
1
Q
Homeostasis
A
- Involves mechanisms which detect the state of the internal environment, and also correct the situation to return the body to its optimal state
- Glucose levels play an important role- monitored by sensors in the liver and hypothalamus
- A DECLINE in glucose levels in the blood increases hunger
- A RISE in glucose levels leads to feelings of satiation
2
Q
Draw the dual- centre model
A
NEURAL AND HORMONAL MECHANISMS INVOLVED IN THE CONTROL OF EATING BEHAVIOUR, INCLUDING THE ROLE OF THE HYPOTHALAMUS, GHRELIN + LEPTIN
3
Q
Lateral Hypothalamus (LH)
A
- “Feeding centre” or “on switch” of the hypothalamus, contains cells that detect levels of glucose in the liver
- LH is activated when glucose levels fall below a certain level
- Causes an individual to become hungry and triggers the motivation to eat, along with searching for and preparing food
4
Q
AO3 Lateral Hypothalamus
A
- A strength of the LH switching eating behaviour is that damage to the LH in rats causes aphagia (absence of eating)
- However, the stimulation of the LH causes feeding behaviour
5
Q
Role of Leptin
A
- Hormone produced by adipose (fat) cells
- Levels of leptin in the blood increase along with fat levels and these are detected in the brain by the VMH
- Is an appetite suppressant, contributes to VMH satiety mechanism
- Once levels increase beyond a certain point, the individual feels full and stops eating
AO3:
- Injecting ob/ob mice with leptin causes them to lose weight
6
Q
Role VMH
A
- Is the “satiety centre”, the “off switch” of eating behaviour
- Eating food provides the body with glucose, so the levels of glucose circulating in the bloodstream and stored in the liver (as glycogen) rise once again- these levels are detected by cells in VMH
- Activity in the VMH is then triggered once glucose levels increase past a set point
- LH activity is inhibited at the same time
- The individual becomes satiated- they fell full and stop eating
- INCREASE serotonin DECREASE food intake
7
Q
AO3 of VMH
A
- Damage to the VMH causes rats to overeat, leading to hyperphagia.
- Stimulation of this area inhibits feeding
8
Q
Role of Ghrelin
A
- Hormone secreted by the stomach
- Hormonal marker of how long since we have last eaten because the amount produced is closely related to how empty our stomach is- MORE ghrelin is released LONGER we can go without food
- Ghrelin levels are detected by receptors in arcuate nucleus
9
Q
AO3 of Ghrelin
A
- Wren found that participants either received saline or ghrelin intravenously and appetite was measured
- There was a significant increase in food consumption in the ghrelin condition
10
Q
AO3 of the dual- centre model
A
- A criticism of the dual- centre mdel is that it has an evolutionary approach
- Hunger mechanisms must anticipate and prevent energy deficits not just react to them
- Shows there must be other psychological mechanisms in place for eating- e.g boredom and sadness
- A criticism of the dual- centre model is that it has a deterministic approach
- E.g if blood sugar DECREASES and Gherlin INCREASES we will eat.
E.g fasting demonstrates free will
11
Q
Evolutionary explanation for food preferences
A
- The evolutionary argument is that any common food preferences we see today must exist because they provided an adaptive advantage
- Those distant ancestors who had such preferences would have been more likely to survive and reproduce
- Therefore we have inherited such preferences
12
Q
Environment of evolutionary adaptiveness
A
- The EEA refers to the ancient environment in which certain traits or behaviours evolved.
- It highlights the selection pressures during our ancestral past that shaped adaptations like food preferences, social behaviours, or fear responses.
13
Q
Preference for sweetness
A
Food preferences are linked to sweet taste as it is a reliable signal of high energy food
- Steiner placed sugar on the tongues of newborn humans and found positive facial expressions
- This reaction supports the theory because babies don’t have the cognitive abilities to learn what facial expressions to have when trying different foods. Their reactions are real, adaptations.
- Therefore, it has face validity because it makes sense that people will have displeasure when trying bitter food and that would suggest that they are harmful.
- Fructose is a ‘fast acting’ sugar providing energy very quickly and is present in ripe fruits, which would have been a favoured food for distant ancestors
14
Q
Preference for fat
A
High- calorie food such as fat were not readily available to our evolutionary ancestors
- Learning to prefer foods which are high in calories would have carried a definite advantage because calories provide energy important for survival.
- As fat contains twice as many calories as the equivalent amount of protein or carbohydrates a taste preference for fat is therefore the most efficient route to ensuring high energy food consumption.
- It also contributes to palatability (making food taste good)
15
Q
Evaluation for the evolutionary explanation for food preferences
A
- Research by Bell has shown that early exposure to a sweet taste is not necessary for children to develop a preference for such foods.
- E.g People from Northern Alaska that had no experience of sweet foods have been shown to develop a preference for such despite no previous exposure.
- Across the research, no culture without previous exposure to sweet food and drink has rejected such when exposed to it suggesting an innate response. This supports the idea that food preferences are evolutionary.
- Suggest it’s learnt rather than biological
- Criticism is that the evolutionary explanation for food preferences is biologically deterministic.
- This approach argues that our food preferences are determined by factors inherited from the EEA.
- However, some people choose not to be victims of their predetermined taste.
- This is a bad because it assumes people have no free will about their taste preferences and will only want food beneficial to survive or taste.
An example of people preferring sour food over sweet foods contradicts this, it doesn’t impact their survival. - This can lead to low self efficacy
16
Q
Neophobia
A
- Fear of anything new, especially a persistent and abnormal fear
- Sufferers are characterised as significantly restricting the volume/types of food they eat - causing a multitude of effects on the body.
17
Q
Food neophobia
A
- So-called “picky eaters,” who are unwilling to eat more than a handful of familiar items, may actually have food neophobia.
- This can be a learned behaviour related to their strong feelings of disgust when they have tried certain flavours or textures.
- Most kids outgrow food neophobia as they mature and taste buds evolve.
18
Q
Evaluation of neophobia
A
WEAKNESS:
- Neophobia cannot explain cultural differences in food preferences and avoidance.
- Neophobia today does not have an evolutionary benefit and can lead to malnutrition
STRENGTH:
- The fact that there are only two taste receptors for sweet tastes but 27 for bitter tastes suggests an evolutionarily determined need to avoid bitter-tasting toxic foods.
- Sweet foods are rarely poisonous so they would be perceived as safe to eat, while sour or bitter foods may be toxic
19
Q
Taste Aversion
A
- An innate predisposition to learn to avoid potentially toxic foods, which are signalled by a bitter or sour taste.
- Additionally, the animal avoids eating what made them ill.
20
Q
Evaluation of Taste Aversion
A
- An application of Learned taste aversions is that children with neoplastic diseases had an unusual ice cream that was given to them before their drug treatments.
- They were experiencing gastrointestinal toxicity due to the drugs but were subsequently less likely to choose that ice cream again. - It is suggested that taste aversions induced by drug-associated symptoms may contribute to the appetite loss experienced by cancer patients.
21
Q
The role of learning in food preferences: social influences
A
Cuddle (UCS) + Chocolate (NS) = comfort (UCR)- Food becomes associated with feelings of happiness
Chocolate (NS) = Comfort (CR)
Eating vegetable (UCS) > rewarded
Family meals + happy
- More likely to eat in future- operant conditioning
Social learning- model role model
(negative attitudes) See mum > food = depressed > learn the same association
See model drinking coffee > praise
Socialising agents include parents, peers and media
22
Q
AO3 Role of learning in food preference: social influences
A
- Research suggests a link between parents and their children in terms of snack food intake, eating motivation and body dissatisfaction- This supports the learning theory- shows that parents and children respond in a similar way
- Researcher used peer modelling to change someone’s preferences to vegetables
- E.g children were seated beside someone who preferred a different type of vegetable to themselves
- At the end of the study children showed a shift in their food preferences which was still evident several weeks later- This shows it had a strong effect- which shows that children are using other children as role model- changing their behaviour- learning through modelling
