13.4.3 Explanations for the Success & Failure of Dieting

• Dieting is when a person intentionally restricts their food intake to achieve a goal such as weight loss or improved health
• Research suggests that those who try to lose large amounts of weight in a short amount of time by restraint have less success than those who set smaller, slower and more realistic targets towards a more long-term goal (Bartlett, 2003)
• For success at dieting, the boundary model suggests that the psychological and physiological boundaries of hunger and satiety should be set close to one another, thus reducing the chance of overeating and dieting failure
• If the psychological and physiological boundaries were set closer to one another, then the dieter would be less likely to go beyond their psychological boundary due to hunger or overeating and the diet would be more successful
• Even if dieting under medical supervision, individuals should also be involved in personal target setting to create a sense of ‘ownership’ of their dieting
• More personally realistic targets can be flexible and designed for the individual, rather than  based on some unachievable ideal that makes failure and disinhibition more likely
• Social support from friends, family and dieting organisations (e.g. Weight Watchers) has also been shown to be important in dieting success, as it allows for careful monitoring and positive feedback and encouragement when restraint wavers (Miller-Kovach et al, 2001)

Setting SMART goals can help achieve dieting success.

• Heatherton and Polivy (1992) initially presented the spiral model of chronic weight-loss dieting as an explanation of how individuals who compare themselves to an ideal physique and feel like they do not match this ideal can become trapped in a downward spiral of restraint and disinhibition
• The spiral model of dieting makes it clear that this does not happen to everyone, but to mainly to those who have low self-esteem
• According to the spiral model, dieters with low self-esteem are more likely to have difficulties in their self-control attempts, but are also psychologically susceptible to the societal pressure to be thin and so they continue trying to diet
• The stress they suffer lowers their self-esteem further, making them even more likely to fail, especially as metabolic efficiency often increases while dieting meaning weight loss slows down 
• This perceived failure to follow a diet makes the dieter’s low mood worse and they become more prone to disinhibited overeating
• The spiral model proposes that this downward spiral can eventually produce mood disorders (depression or anxiety) or eating disorders in at-risk individuals 

The spiral model of dieting failure’

• Hedonic theory states that those who engage in food restriction can become more sensitive to eating behaviours motivated by pleasure rather than just physiological hunger
• This is a particular issue when the environment is food rich, as then hedonic eating conflicts with the goal of eating just for satiety and particularly with the goal of restraint
• The more the individual tries to restrict certain foods, the more desirable they seem until they are sometimes seen as a ’reward’ for restraint
• Once dieters lose touch with their physiological cues of hunger and satiety, then disinhibition becomes a greater risk, and they will have difficulty stopping eating when they are full

Research which investigates explanations for the success and failure of dieting

• Nolen-Hoeksema (2002) found females on strict low-fat diets developed low moods, which they addressed by disinhibited eating, with 80 per cent of these going on to develop clinical depression within five years, suggesting dieting can lead to a risk of developing mental disorders
• Lowe et al. (2004) found an average of 71.6 per cent of Weight Watchers members maintained a body weight loss of at least 5 per cent, indicating that social support helps with long-term diet success

Evaluation of explanations for the success and failure of dieting 

Strengths

• Research has contributed to the formation of effective diets and weight-reduction programmes such as Weight Watchers, which reduces costs to the health service, as obesity is often associated with poor health
• Research that acknowledges the complexity of explanations for obesity helps to reduce the stigma associated with an older simplistic model that stigmatises obese individuals for their supposed lack of control over their eating

Weaknesses

• Explanations for success and failure of dieting ignore individual differences as many people are successful while others fall into a pattern of perpetual dieting behaviour that cannot be explained solely by low self-esteem
• Research has suggested that obese people start regaining weight after six months due to failing to maintain behavioural changes, suggesting factors such as a loss of motivation and social pressure have negative influences, which are factors not considered by the spiral model and hedonic theory (Jeffery, 2000)

Link to Issues & Debates: 

Explanations for the failure of dieting are deterministic, as they see diets failing because of low self-esteem and because of conflicts between hedonistic eating and the need for restraint. However, there is some acknowledgement of free will in the explanations for the success of dieting, where personal diet plans and mutually agreed achievable goals put the individual in control of their own weight reduction diet.

Research into the success and failure of dieting can be seen as gender-biased, and specifically it has a beta bias, because it tends to focus on females but apply the findings to both sexes, whereas it is important to look at male dieting behaviour as well, as it may be for different reasons and follow a different path.