Psychological explanations for obesity

Key terms

• restraint theory

• disinhibition

• boundary model

Restraint theory

A cognitive explanation which argues that obesity is the paradoxical outcome of attempts to restrain eating (e.g. dieting)

Herman and Polivy (1975)

• developed restraint theory

• argued that restrained eating is counterproductive and self defeating

• majority of people who restrain their eating fail to lose any weight

• can lead to an obsession with food

Cognitive control

Cognitive control = where restrained eaters set strict limits on their food intake

• they categorise food into groups: ‘good’ and ‘bad’ and create rules about which foods are forbidden

• a restrained diet is a very organised way of imposing control which individuals believe is the way to lose weight

Paradoxical outcome

• result of restrained eating is that it causes the individual to become more preoccupied with the food rather than less

• no longer eat when they are hungry and stop when they feel full

• eating behaviour is no longer under physiological control - now they actively attempt to ignore the physiological indicators that signal hunger and satiety

• this leads to disinhibition of eating behaviour

Non-physiological food cues

• mood - feeling depressed

• media images

• smells

• sights

there are external and internal cues

these cues are called disinhibitors

Disinhibition

• period of restrained eating is followed by disinhibited eating/binge eating

• caused by disinhibitors (food related cues)

• restrained eaters are vulnerable to these cues and the loss of control leads to unrestrained eating

• disinhibition is controlled by cognitive factors - distorted thinking - all or nothing thinking

The boundary model

Herman and Polivy (1984)

• explained how restrained eating can lead to unsuccessful dieting and potentially obesity

Explanation

• when energy levels dip, we feel an aversive state of hunger so we are motivated to eat

• eating to fullness creates an aversive state of discomfort so we stop eating

• the zone of biological indifference is where cognitive and social factors have their greatest influence on food intake

Explanation if you are a restrained eater

• have a lower hunger boundary so are less responsive to physiological feelings of hunger - cognitvely pre-occupied with food

• have a higher satiety boundary so need more food before they consider themselves full

• more of their eating comes under cognitive rather than physiological control

• it is claimed that dieters set themselves a cognitive diet boundary which limits what they can eat. if they ever cross this boundary the ‘what the hell effect’ kicks in and they will then continue to eat until they are full and reach their physiological boundary which is higher than for non-restrained eaters

AO3 points

• supporting research

• disinhibiting effects of the media

• contradictory research

• restraint is multifaceted

• practical applications

AO3 - supporting research

EV = Wardles and Beales (1988) - 27 obese women randomly allocated to 3 groups. 1 = restrained, 2 = exercise regime/no restraint, 3 = control. findings = restrained ate sig. more and consumed more calories than the 2 other groups

EX = suggests a restrained diet causes overeating which leads to weight gain and obesity

C = Savage et al (2009) - longitudinal study into restrained eating - measured dietary restraint and disinhibition in 163 women at the start of the study and every 2 years afterwards over a 6 year period - found restrained eating while dieting leads to weight loss rather than weight gain

Boyce and Kuijer (2014) - restrained eaters consumed a higher quantity of unhealthy snacks

LB = results suggest that teaching restrained eaters how to pay less attention to the media body ideal images might be an

Restraint is multifaceted

P = restraint is a more complex phenomenon than the boundary model indicates

EV = research identified 2 diff. forms:

• rigid restraint - all-or-nothing approach to limiting food intake

• flexible restraint - allows restrained eater to eat limited amounts of some