eating behaviour

• Evolutionary explanation - the idea that we have adapted our food preferences to the environment.
• food preferences - salt, sweet, fat
• taste aversions - sour and bitter
• neophobia - the fear of trying new foods more common in children.
• The role of learning - food preferences are learned through social and cultural factors
• social factors include: classical conditioning, operant conditioning, social learning, family, peers, media
• cultural facotrs include: cultural influences, social norms, meat eating
• Dual control theory - eating behaviour is governed by homeostasis and uses the dual control model to explain eating behaviour.
• lateral hypothalamus - switches on eating, reponds to a drop in blood glucose levels and increases feelings of hunger
• ventromedial hypothalamus - switches off eating, reponds to a rise in blood glucose levels.
• hormones - there are 2 hormones involved in eating behaviour these are Ghrelin and Leptin
• Ghrelin - secreted by the stomach, marks how long since we last ate, amount is related to how empty to stomach is, when ghrelin is high it signals the lateral hypothalamus
• Leptin - hormone produced by fat cells, levels increase with fat cells, when levels are high is acts as an appetite supressant, stop eating
• genetic explanation for anorexia - nature, passed down,studied two ways (concordance rates and candidate genes)
• neural explanation for anorexia - 2 neurotransmitters - dopamine and serotinin
• serotonins role in anorexia - too much causes anxiety, starvation alleviates anxiety but creates more sensitivity to serotonin - vicious cycle
• dopamines role in anorexia - overactive dopamine receptors in the basal ganglia, find dpoamine anxiety provoking, avoid eating
• social learning theory of anorexia - indirect learning - identification, observation, immitation. role models in the media lead to vicarious reinforcement as they see models being rewarded for thinness. media and culture influences. mediational processes.
• mediational process - attention, retention, motor reproduction, motivation
• family systems theory - communication and interaction within the family mainly mother and daughter.

  an anorexic family have 4 key characteristics: enmeshment, ridgitdity, conflict avoidance.

  leads to the adolescent feeling out of control, they regain this control through starvation
• cognitive explanation for anorexia - cognitive distortions and faulty thinking cause anorexia

  3 key ideas:

  distrubed perceptions

  irrational beliefs

  cognitive inflexibility
• genetic explanation for obesity - nature, passed down, studied 2 ways (concordance rates and polygenic)
• neural explanation for obesity - 2 neurotransmitters: serotonin and dopamine
• role of serotonin in obesity - levels are too low so they eat more to gain the same pleasure
• role of dopamine in obesity - less D2 receptors so not as sensitive to it so eat more to gain the same pleasure
• restraint theory - cognitive

  setting strict limits is counterproductive because you becoming pre-occupied with food so end up eating more, you ignore physiology
• disinhibition - a period of restraint is often followed by disinhibition

  this is where you eat what you want.

  restrained eaters are vulnerable to cues such as mood (internal) and the media (external)

  cue = disinhibition. leading to a loss of control

  cognitive process - all or nothing
• Boundary model - restrained eaters place cognitive boundaries upon themselves, they have a larger range between hunger and satiety. they feel hunger for longer and it takes more food to satisfy them. when they break the restraint it acts as a disinhibitor. they experience the 'what the hell' phenomena
• The role of detail (Redden) - the secret to successful dieting = the attention we pay to it people usually like experiences less when they repeat them, repetition and monotomy makes dieting hard. enjoyment of an eating regime depends on how much repetition is percieved.

  to overcome think about each thing you eat in detail
• the role of denial - attemting to suppress or deny a thought had the opposite effect - more prominent

  wegener (1994) refers to this phenomenon as 'the theory of ironic processes of mental control'

  it represents a paradoxial effect of thought control, as soon as you deny food - it simulataneously becomes more attractive