Psychological Explanations for Obesity

Psychological explanations for obesity: Psychological causes

Several psychological explanations for obesity suggest different ways obesity is caused. These explanations include cognitive, behavioural, environmental, and social factors.

Keys et al. (1950) conducted research on WWII soldiers and drew some interesting conclusions. They had American soldiers who had no interest in fighting start a starvation diet. These soldiers were already 'conscientious objectors' because of their unwillingness to fight. Then, when they started the diet, the more they were denied food, the more they thought about it. This indicated to Keys et al. that the more restricted one's eating becomes, the more one thinks about food, thereby turning into a risk factor for obesity.

The three main psychological explanations of obesity are:

1. Restraint theory
2. Disinhibition
3. The boundary model

Psychological Explanations For Obesity: Restraint Theory

Restraint theory is a cognitive theory of obesity developed by Herman and Polivy (1975). Since trying to lose weight involves restraining one's eating through types of food and amounts of food, Herman and Polivy suggested that restrained eating is a self-defeating practice, since many people who do this don't succeed in losing weight. This even goes to the extent of some people becoming obese. Two factors are part of restraint theory: cognitive control and paradoxical outcome.

Cognitive control

Restrained eaters set strict limits on themselves by categorising foods as 'good' and 'bad', 'forbidden' and 'allowed', and the specific amounts of food they need to lose weight. This restricted diet is a way of forcing control in a highly organised manner, which obese people believe is the way for losing weight.

Paradoxical outcome

Whilst there is increased control of overeating, this doesn't mean that the person will be able to lose weight successfully. The person is often more preoccupied with food due to thinking so much about what they can and can't eat. Due to this cognitive control, the restrained eater doesn't eat when their body signals that they're hungry, nor stops eating when their body signals fullness. This leads to disinhibition of eating behaviour.

Psychological Explanations For Obesity: Disinhibition

Restrained eating isn't the only cause of obesity; just how it starts. When disinhibition comes into play, it forms a dysfunctional cycle along with restrained eating.

After a period of restrained eating, they get tired of restricting themselves and start eating as much as they want, often taking an 'all or nothing' approach. All or nothing is when the person believes that once they start to overeat or eat food they consider 'bad', they continue doing so because they think they might as well eat everything as they have already failed.

Psychological Explanations For Obesity: The Boundary Model

Food intake lies on a continuum ranging from feeling hungry to feeling full/satiated. Different biological processes determine how much and when we eat on each end of this continuum.

Therefore, eating starts at the boundary of hunger and ends at the boundary of fullness/satiety. Between these two boundaries is a space of biological indifference, in which there is the minimal influence of biological processes. This is where we are neither hungry nor full, and cognitive or social factors affect our eating behaviour.

Restrained Eaters

Restrained eaters have a lower hunger boundary, so they are less responsive to these feelings when they feel hungry. But they also need more food to feel full because they have a higher satiety boundary. Therefore, the zone of biological difference is longer, meaning their eating is more time under cognitive than physiological control. This makes them more susceptible to disinhibition effects.

Restraint theory fails to acknowledge those who successfully diet through restrained eating, and people with anorexia may overeat/restrict their eating without becoming obese.

Psychological Explanations For Obesity: Psychological Interventions

There are different psychological interventions for obesity, but the most common is cognitive behavioural therapy (CBT). This includes goal-setting, self-monitoring, stimulus control, substituting behaviours, and restructuring cognitions. Many studies have found that CBT has successfully reduced patients' weight who had the treatment (Fabricatore, 2007).