Describe and evaluate the psychological explanations of obesity

Essay Plan AO1 - "Describe" - the psychological explanations of ObesityPoint 1:    Restraint Theory - Herman and Polivy, people attempt to lose weight by limiting the amount they eat which is counterproductive.Cognitive Control - Restrained eaters set themselves beliefs that categorise foods into good and bad - consciously thinking about their weight and eating.Paradoxical Outcome - this results in the restrained eater becoming more preoccupied with food rather than less. By placing limits on what and how much they eat, the restrained eater no longer eats when they are hungry and stops when they are satiatedLink: Their eating is no longer under physiological control they actively ignore these indicators of hunger which leads to disinhibition of eating behaviour. Point 2:     After a period of restrained eating it is often followed by disinhibition - the individual eats as much as they want, "binge eating"Restrained eaters are vulnerable to internal and external food related cues such as mood (internal) and smells (external). e.g. individual can eat more to increase their dopamine levels when they are sad.These cues are disinhibitors and lead to loss of control over restrained eating. Cognitive Process - All or Nothing thinking, fails one day to keep their restriction are more likely to binge because they see themselves as already having failed Link: Herman and Polivy describe restrained eaters as being different from the psychological norm of eating behaviour. Point 3: Boundary Model - food intake exists on a continuum from hungry to fullBiological process determine how much we eat at each end of the continuumEnergy levels low= aversive state of hunger - motivated to eatEating to fullness= aversive state of discomfort - stop eatingBiological indifference - between these two points, biological processes have minimal effects, but cognitive and social factors have their greatest influence.Restrained eaters - low hunger boundary - less responsive to feelings of hunger BUT have a higher satiety boundary - need more food before full.Have a wider zone of biological indifference - eating comes under cognitive rather than physiological control making them more vulnerable to effects of disinhibition. AO3 - "Evaluate"Issues·      Supporting Research: Wardle and Beales - 27 Obese women, divided into group of restrained and non-restrained eaters. Restrained eaters consumed the most calories overall, generally ate less throughout 7-week experimental period but experienced occasional "binge"- increase in food consumption past satiety.Contradictory Evidence: Savage et al. - Longitudinal study into restrained eating, 163 women, measured weight, dietary restraint and disinhibition every 2 years over a 6 year period. found increase in restraint lead to a decrease in weight. - Could be due to social desirability bias in participants. ApproachesEvolutionary Approach - During the EEA humans did not have a regular food source, would often have periods of starvation and then binged on food when they had more. Lead to an evolutionary adaptation in humans that when they restrict themselves their evolutionary response is to then eat more food.DebatesNature vs NurtureNurture Argument - Social Learning theory - environmental triggers cause restrained eaters to eat more. Boyce and Kuijer - showed restrained and unrestrained eaters’ images of models in the media before giving them a ten minute taste test where they could eat as much as they wished. Found restrained eaters ate more. Nature Argument - Evolutionary - increase in consumption after periods of restraint are due to a biological adaptation in human evolution due to changing food availability in the EEA.