Explanations for Obesity (AQA A Level Psychology): Flashcards

Wang et al. (2001) found obese individuals had significantly fewer dopamine D2 receptors in the striatum.

It reduces pleasure in eating, so overeating is an attempt to activate reward centres. Obesity is seen as a food addiction working like other addictions.

PET scans showed people with one version of the DRD2 gene had 30–40% fewer D2 receptors, so they get less reward from eating and are more likely to overeat.

Concordance rates of 61% to 80% across 12 twin studies, showing a substantial genetic component from childhood into adulthood.

The search for effective gene therapies for the treatment of obesity.

'Knockout' mice with no functioning serotonin 2C receptors showed late-onset obesity.

False.

The research is correlational, so low levels could be a cause or an effect of obesity.

Much of it is based on genetically modified mice, while human eating is also shaped by social and cultural factors.

They emphasise genetic and neurochemical causes, underplaying nurture such as lifestyle, diet and cultural factors.

Biological theories of obesity may be culturally biased because research is largely based on Western populations.

Restraint theory (Herman & Polivy, 1975) is a cognitive theory arguing that restrained eating is counterproductive and self-defeating, as many restrained eaters overeat to the point of obesity.

Psychological stress, lowered mood and cravings.

Restrained eaters categorise foods as 'good' or 'bad' and create rules about which are allowed, replacing physiological control with conscious control.

The paradoxical outcome of restraint is that the eater becomes more preoccupied with food, ignoring signals of hunger and satiety.

Individuals tire of restricting themselves and eat as much as they want, often taking an 'all or nothing' approach.

Disinhibitors are internal cues (such as lowered mood) and external food-related cues (such as media images) that lead to a loss of control over restrained eating.

Once disinhibited, the individual reasons that having already broken their rules there is no point in stopping, marked by passivity and resignation.

False.

Some cycle between dieting and bingeing (yo-yo dieting), while others continue to overeat, leading to obesity.

The boundary model (Herman & Polivy, 1984) places food intake on a continuum from an aversive state of hunger at one end to an aversive state of satiety at the other.

A zone of biological indifference, where eating is under cognitive and social control rather than physiological control.

Unrestrained eaters eat until they reach satiety. Restrained eaters eat until their cognitive boundary, the limit they have set themselves.

They have a lower hunger boundary and a higher satiety boundary, so their zone of biological indifference is wider.

Restrained eaters ate significantly more ice cream than unrestrained eaters if given a milkshake first, having already exceeded their cognitive boundary.

Female students given negatively phrased diet intentions ate unhealthy snacks more often the following week, consuming more calories than controls.

Wardle and Beales (1988) found that after seven weeks the restrained eaters consumed the most calories overall, supporting restraint as a causal factor.

True.

Mesarič et al. (2023) report CBT for binge-eating and obesity developed from these explanations.

Over six years, increases in restrained eating were linked to decreases in weight, the opposite of what the theory predicts.

Much data comes from self-report questionnaires and eating diaries, which are subject to social desirability bias.

It reduces obesity to cognitive processes, overlooking biological and social factors such as genetics, economic access to food and cultural norms.

Psychological explanations of obesity are nomothetic, aiming to establish general laws, which allows large-scale treatments like CBT but may overlook individual differences.