PSY3 Eating Behaviour

Question 1

Attitudes to food/eating behaviour

**Social Learning: A01 **Parental Modelling

Answer 1

• Children acquire attitudes by observing behaviour of their parents
• Parental att. inevitably affect kids
  
  • parents control foods bought/served in home
• Brown/Ogden outline no. of ways parents exert influence:
  
  • basic food pref
  • healthy quality of diets
  • concerns of weight gain/disordered eating behaviour
• Parents exert direct role through use of reward/punishment (operant)

Question 2

A02 Parental modelling

Answer 2

• Brown/Ogden - gen. association b/w parents/kids attitudes:
  
  • correlation b/w parents/kids in terms of snack food intake, eating motivations and body dissatisfaction
• Birch/Fisher - found best predictors of daughters’ eating behaviour were mums’ dietry restraint/perception of risk of daughters becoming overweight
• Hall/Brown - mums influence daughter’s satisfaction/dissatisfaction w/ body:
  
  • mother’s of girls w/ anorexia show greater body dissatisfaction than mums of non-disordered girls
• Birch - parents directly influence habits through use of praise/reward:
  
  • praise from adult inc. food pref. for previously disliked food
  • but relationship is complex
    
    • manipulating pref. may create unitended conseq/counterproductive
      
      • kids offered juice as a means to be allowed to play showed that using juice as reward reduced pref. for juice (Lowe)

Question 3

Attitudes to food/eating behaviour:

A01 Peers

Answer 3

• As kids move into wider social world, become inc. influenced by food pref. of friends
• Gladwell/Harris - best way to get a child to eat something new is not by parental encouragement, but immersing child in room of kids who already like that food
• Teen years, children may actively differentiate self from parents/parents’ generation
• Certain foods favoured by teen compared w/ older age groups e.g. pizza, fried foods (Demroy-Luce/Motil)

Question 4

A02 Peers

Answer 4

• Birch - children will eat veg if friends do:
  
  • selection/consumption of veg by pre-schoolers influenced by choices of peers
  • children lunched next to kids who pref. different veg to self
    
    • kids showed shift in veg pref. which persisted at follow-up assessment weeks later!
• Lowe - impact of observational learning shown in intervention study designed to change eating behav:
  
  • ​kids watched series of DVD adventures feauturing ‘fun/cool’ ‘Food Dudes’

Question 5

A03 Attitudes to food/eating behaviour

Answer 5

• Problems w/ generalisability - studies on clinical/non-clinical population:
  
  • limits degree generalise from one group to another, thus degree to which studies offer understanding of causal factors
• ​Gender bias - conc. on women’s attitudes
  
  • male homosexuality risk factor in development of d/o (Siever).
    
    • Findings attributed to male gay subculture - emphasis on lean, muscular body ideal
  • limtd view
• ​Need to consider other factors - emphasise imp. of ext. factors, underest. contribution of non-psycho exp.
  
  • though may exp. specific likes/dislikes/habits, our basic food pref. determined by evolutionary forces
    
    • humans have strong pref. for nutrient dense foods (meat/fat)
      
      • pref. set in EEA and only moderated by direct experience

Question 6

Explanations for success/failure diets:

A01 Restraint theory

Answer 6

• Restraint inc. probability of overeating
• Herman/Polivy developed Boundary Model to exp. why dieting –> overeating
• Hunger - when/how much to eat
• Satiation - occurs when brain judges that eating more not in person’s best interest
• For ancestors, finding food required effort/time, so when person’s eaten optimal amount, brain signals stop, do something to aid survival!
• When food plentiful, satiation reached easily
  
  • don’t need to eat large amounts in single meal as it’s avail in near future
• But reg. bouts hunger indicate uncertain food supply
  
  • brain biochem adjusts to satiation less easily achieved - brain judges that food’s scarce
• When opportunity to comsume arises, org. should consume lots, for it may be while until another opportunity arises
• Dieting widens gap between hunger/satiation

Question 7

A02 Restraint theory

Answer 7

• Wardle/Beale - 27 obese women: women in diet cond. ate more than women in exercise & control group; confirmed model’s predications.
  
  • Strength - assessment under lab cond.
  • Gender bias - research only conc. on success/fail of women’s dieting; studies providing insight only offer limtd exp.
    
    • Not generalisable to opposite gender? Don’t provide universal exp. for reasons of success/failure.
• Implications for obesity treatment - theory says restraint –> overeating, yet treatment commonly used as solution to exc. weight gain.
  
  • But failed attempts to diet leaves obese depressed/feeling failure
    
    • This is why there may be more emphasis on fitness than diet!
    • Ogden - though obesity not necessarily result of overeating, it may be consequence of obesity if restraint used as treatment.

Question 8

Explanations for success/failure diets:

A01 Role of denial/Ironic processes

Answer 8

• Research shows trying to suppress/deny thoughts freq. has opposite effect, making it more prominent (Wegner/white bears)
• A.K.A ‘theory of ironic processes of mental control’ - rep. a paradoxical effect of thought control i.e. denial backfires
• Denial of food tends to make us think of it more than normal; can become pre-occupation
• As food’s denied, it simultaneously becomes more attractive
• Dieter may find only way to deal w/ issue is to succumb to temptation, consume food in question

Question 9

A02 Role of denial

Answer 9

• Practical application - Wegner suggests dieters think of issues differently; rather than thinking “I must not eat” should reformulate challenge to “I must get fit”.
  
  • Ppl may be more successful by focusing on fitness, not diet.
• Soetens - disinhibited restrained eaters used more thought suppression than unrestrained/low disinhibition, showed rebound effect after (thought of more food)
  
  • Restrained eaters who overeat try to suppress thoughts more often, but when they do, think more of food after

Question 10

A03 of success/failure of diets

Answer 10

• Culturally biased - some cultural grps find it harder to diet successfully due to natural inclination to obesity
  
  • Asian adults more prone to obesity than EU (Park); asian kids/teens have a great central fat mass compared to EU (Misra)
• Due to lifestyle or genes? - issue to degree which lifestyle determines failure/success
  
  • likely that genetic mechanisms influence weight
    
    • H. levels enzyme LPL associated w/ greater weight gain.
    • Researchers believe weight loss activates gene prod. LPL, may exp. why it’s easier to regain lost weight than for one who has never been obese to put on weight
      
      • Determinism plays greater role in success, not free will

Question 11

Neural mechanisms in eating behaviour:

A01 Homeostasis

Answer 11

• Involves mechanisms which detect state of int. environment/correct situation to restore envrionment to optimal state
• Hunger inc. as glucose levels dec.
• Decline in glucose activates lateral hypothalamus, results in hunger, cause person to search/consume food = levels to inc. again
• Activates ventromedial hypothalamus, leads to feelings of satiation, which inhibits feeding

Question 12

A02 Homeostasis

Answer 12

• Lashley - evidence for role of hypothalamus:
  
  • cut out diff areas of rats brain to see effect of lesions on behavior
  • LH identified as ‘hunger centre’, VMH ‘satiety centre’
    
    • lesions to LH caused animals to stop eating spontaneously
    • reverse occurred after lesions made to VMH
      
      • ​lesions in VMH caused rats to overeat!
      • Probs w/ animal studies!!!!
• ​Limitations - for hunger mechanism to be adaptive, must anticipate/prevent energy deficits, not just react!
  
  • ​Suggests hunger only triggered when energy falls below desired level
    
    • Incompatible w/ situations in which systems would’ve evolved!
  • For mechanism to be adaptive, must promote levels of consumption that maintain bodily resources above optimal to act as buffer against future lack food

Question 13

Neural mechanisms in eating behaviour

A01 Role of leptin

Answer 13

• Fat hormone leptin is an example of a neuropeptide
• Secreted from fat cells into the blood and signals the brain (via the hypothalamus) that calorie availability is high - leads to satiation
• When fat reserves are used for energy production, leptin secretion falls
  
  • hypothalamus detects this, interprets low leptin as lack of calories and generates sensation of hunger

Question 14

A02 Role of leptin

Answer 14

• Zhang - evidence for role of leptin:
  
  • some mice received 2 copies of gene related to leptin regulation (ob/ob)
    
    • have tendency to overeat, esp. foods h. in fat/sugar
  • ob/ob mice have defective genes for leptin regulation
    
    • injecting ob/ob mice w/ leptin causes them to lose weight dramatically
  • direct evidence of leptin in human eating behav come from rare cases of ppl born w/ leptin deficiency
    
    • can’t control their eating, freq. become obese - take leptin injections to return to normal weight
  • Problems w/ animal research!!!!!

Question 15

Neural mechanisms in eating behaviour:

A01 Role of Ghrelin

Answer 15

• Ghrelin, **a **neuropeptide thought to be the ‘hunger hormone’
• Produced in stomach and hypothalamus
• Levels inc. before meals as stomach muscle contracts/stretches
  
  • Dec. after meals when stomach’s full
• Receptors of ghrelin found in lateral hypothalamus (brain!), h. levels associated w/ hunger and low levels w/ satiation

Question 16

A02 Role of Ghrelin

Answer 16

• Zigman - explains why low mood leads to comfort eating:
  
  • ghrelin linked w/ appetite regulation/stress resistance
  • mice genetically engineered to prod. low levels of hormone
  • mice exposed to social stress (sharing enclosure with big mice)
  • normal would would inc. consumption of h. calorie food - special mice didn’t!
    
    • suggest ghrelin imp. in triggering comfort eating
      
      • suggests biochem mechanism to block this chemical action may be possible treatment for mood-related eating disorders!
• Probs w/ animal studies!!!!

Question 17

A03 of neural mechanisms in eating behaviour

Answer 17

• Reductionist - implications of psychological/physiological hunger:
  
  • there’s diff b/w physical hunger and psychological hunger
    
    • other learned/cognitive factors:
      
      • e.g availability of rich foods - ppl tend to gain weight when food plentiful
      • smell - some can’t resist feeling hungry even if they’re not physically hungry
    • ext. stimulu provide other ways to signal LH to make up feel hungary even if not physically (Hara)
  • exp. only focus on LH/bio factors - reductionist!!!

Question 18

Evolutionary exp. for food pref.

A01 Preference for meat

Answer 18

• Human ancestors incl. meat in diet to compensate for decline in quality of plants
• Meat diet, full of nutrients, provided the catalyst for brain growth
• We’re hard-wired to consume meat as it was v. difficult to ancestors to obtain this!
• W/o animals, claims Milton, it’s unlikely that early humans could’ve secured enough nutrition from a vege diet to evolve into the intelligent creatures they became!

Question 19

A02 Preference for meat

Answer 19

• Cultural differences in food pref - vast majority of spec. food likes/dislikes appear not to be predetermined.
  
  • Though strong affinity of kids for sweets seem universal, innate response don’t account for broad range of likes/dislikes that develop beyond infancy.
  • Evolved factors clearly important, but exp. w/ diff foods, w/ culture partly determining this, modify this!

Question 20

Evolutionary exp. for food pref:

A01 Taste aversion

Answer 20

• Bait shyness: animals that became ill after eating, developed aversion to that food
• Development of taste aversions aided our ancestors in survival, as surviving from eating poisoned food ensured they would not make same mistake again
• Once learnt, difficult to shift - adaptive quality designed to keep ancestors alive

Question 21

A02/A03 Taste aversion

Answer 21

• Garcia rats who were made ill through radiation shortly after eating saccharin, developed aversion to it v. quickly
  
  • ​associated illness w/ saccharin
• Real-world application - research origins of taste aversion helpful in understanding food avoidance that sometimes occur during treatment of cancer:
  
  • ​some cancer treatments cause gastrointestinal illness
  • when illness pairs w/ food consumption, taste aversions can result
• Bernstein/Webster - gave patients novel-tasting ice cream prior to their chemotherapy –> patients acquired aversion to that icecream
  
  • fled to development of ‘scapegoat technique’ - give patient novel food w/ familiar food prior to treatment
    
    • patient forms aversion to novel food and not familiar
      
      • consistent w/ adaptive avoidance of novel foods - neophobia

Question 22

A02/A03 Evolutionary exp. for food preference

Answer 22

• Reductionist - oversimplifies complex human behaviour to evolutionary mechanisms, ignoring psychological/cognitive factors
• Determinism - overlooks freewill and conscious cognitive and social factors (e.g. dieting, social learning.)

Question 23

Psychological exp. for AN:

Social learning

A01/A02 Cultural ideals/media

Answer 23

• Widely held belief Western standards of attractiveness imp. in AN development
• Studies show many teens (esp. girls) dissatisfied w/ weight/have distorted body image
• Media’s source of influence for body image attitudes maintined by West teens
• Portrayal of thin models on TV/mags signif. in body image concerns/drive for thinness among Western teens girls
• Media doesn’t influence all in same way e.g. ppl w/ l. self-esteem likelier to compare selves to idealised images portayed in media (Jones/Buckingham)

Question 24

A02/A03 Culture/media

Answer 24

• Hoek - AN not confined to West:
  
  • tested view that AN rare in non-West:
    
    • examined records of over 44,000 ppl admitted to hospital over 2 year in Curacao (non-West), where it’s acceptable to be overweight
    • 6 cases of AN, rate claimed to be within range of West
• Bio factors - don’t exp. individual differences:
  
  • fail to exp. why some develop AN and others don’t when they’re exposed same cultural influences/experiences/media
    
    • AN partly influenced by bio/genetic!
• Real-world application - fashion industry acknowledged damaging infl. of media on body image, by signing charter of good will
  
  • Charter first step in stopping eating d/o, promoting healthy body image among young women
  • Charter involves a pledge by fashion houses, advertising agencies/mag editors to use diversity of body types, not stereotype of ‘thin ideal’

Question 25

**Psychological exp. for AN: **

Cognitive

A01 Role of distorted thinking

Answer 25

• Emphasise role of distorted thinking in AN
• Distorted body image - person believes self to be overweight, when they are very much underweight
• Anorexics tend to show dichotomous thinking (seeing everything good/bad, success/fail)
• This thinking carries over to issues of weight, anorexics typically agree ‘thin is good, but thinnest is best’ - normal never agree!
• Anorexia exp. w/ self-serving cognitive biases
• Ppl w/ AN show reversal of overconfidence bias (ppl feel self attractive than others would rate them)
  
  • may lead to low self-esteem/maladaptive behaviour (Jansen)

Question 26

A02/A03 Distorted thinking in AN

Answer 26

• Where do these thoughts come from?
  
  • Prob exp. where these thoughts come from
  • Does thinking lead to change in behaviour or does behaviour change lead to distorted thinking?
  • Most think they’re dynamically linked, dysfunctional thinking leads to disordered eating, and disordered eating in turn, leads to dysfunctional thinking
  • May be unhelpful to think of cognitive distortions as a cause of AN, simply a variable/factor associated w/ AN
• Real-world application - effective therapies:
  
  • cognitive therapists argue focus of therapy should be on desire to be thin
  • challenge thought pattern e.g. by challenging idea that thinnest is best
  • BUT can be very ineffective, as many patients find it challenging/don’t respond well
    
    • if patient doesn’t co-op w/ therapy, can’t be successful
    • so there’s always place for bio/behavioural therapies too!

Question 27

Evolutionary explanation for AN:

A01 Reproduction suppression hypoethsis

Answer 27

• Surbey suggests adolescent girls’ desire to control weight rep. evolutionary adaptation in which girls delayed offset of sex maturation in response to indication of poor reprod. success
• Enabled females to avoid giving birth when conditions aren’t conductive to offspring’s survival
• Surbey argues AN is a ‘disordered variant’ adaptive ability of females to alter timing of reproduction when they feel unable to cope w/ bio/emo/social responsibilities of womanhood

Question 28

A02 Reproduction suppression hypoethsis

Answer 28

• Delayed reprod. sometimes makes sense:
  
  • Anorexica often leads to delayed puberty and suppression of periods in post-pubescent girls
  • These responses make sense if female becomes pregnant at time when infant is unlikely to survive

Question 29

A01 The ‘adapted to flee’ hypothesis

Answer 29

• Proposes symptoms of AN reflect adaptive mechanisms that once caused migration in response to famine conditions
• When person begins to lose weight, physiological mechanisms conserve energy/inc. desire for food
  
  • adaptations facilitate survival in hard times
• But among ancestors, when extreme weight loss due to severe depletion of food resources, adaptation must be turned off so person can inc. chances of survival by migrating to more favourable environment

Question 30

Biological exp. for AN - Neural explanations:

A01 Genetic factors

Answer 30

• Twin studies suggest AN has strong genetic component
• Holland: concordance rates of 25 identical/20 non-identical twins
  
  • 56% identical concordant for AN, only 5% non-identical
• Conclude 80% of variability might be exp. by genes

Question 31

A02 The ‘adapted to flee’ hypothesis

Answer 31

• Why do females stop eating when there’s plenty of food?
  
  • difficult to see what adaptive advantage this behaviour could be
  • evolutionary exp. of food pref suggest humans find difficulty in not eating when food’s available
  • thought there’s a connection b/w starvation and reproductive behaviour, unclear that this extends to anorexia
• Incomplete explanation:
  
  • though adaptive advantage under certain conditions, makes sense
  • doesn’t explain why AN unevenly distributed in human pop’lns
  • AN likelier to be diagnosed in mid-class adolescent girls in developed countries
    
    • likely that cultural factors imp!

Question 32

A02 Genetic

Answer 32

• Limitations of twin studies - don’t prove AN has bio basis:
  
  • identical twins share more than identical genetic makeup
    
    • same gender, look same, behave similarly
      
      • environment/experiences shape us!
      • likely social environment for MZ twins more similar than DZ
    • exp. patterns w/ reference to genetic other bio factors arguably unnecessary
    • as concordance rate for twins not 100%,** show other factors important!!!!**

Question 33

A01 Neurological factors (brain/neurotransmitters)

Answer 33

• NT linked to AN e.g. serotonin/dopamine
• Excessive serotonin activity in hypothalamus has effect of reducing appetite/inc. anxiety
  
  • Both traits of AN
• Effects may be dynamically linked
  
  • If AN reduces food intake, likely they’ll feel less anxious and self-starvation may be reinforced through process of negative reward (operant)
• Pre-natal exposure to female hormones linked to AN:
  
  • ​Procopio: males developed in utero w/ twin sister likelier to develop AN than other males, incl. those who have twin bro
    
    • ​suggests pre-natal exposure to something, possibly female sex hormones signif. risk for developing AN

Question 34

A02 Neurological factors

Answer 34

• Evidence for role of serotonin - evidence for NT in AN comes from action of drugs used to treat AN
  
  • SSRIs, which have direct effect on serotonin regulation effective in treating AN
• Pre-natal development imp - Procopio found risk for males w/ female twin inc. risk of AN 10x
  
  • suggests pre-natal exp. to female sex hormones changes developing brain to inc. likelihood of AN developing

Question 35

IDA of biological exp.

Answer 35

• Real-world application - in US, treatment for AN restricted under many insurance plans as AN not seen as ‘bio based’
  
  • But research creates case for insurance companies to consider AN in same way as other psychiatric cond. that are considered as bio based
• Gender bias - most studies conc. on women
  
  • ​statistics show 25% adults w/ eating d/o are men
    
    • Though doesn’t est. whether men nowadays suffer fr d/o compared to 10 years ago, or whether males escape attention.
    • Still shows AN not exclusively female prob!