Explanations for the Success and Failure of Dieting

Denial

This is where people deny their bodies certain foods in order to diet. However, due to impulses the body ends up craving the food more.

The theory of denial holds that any intentional control of the mind introduces an operating process that directs the conscious attention focusing of our minds on positive thoughts. This process is accomplished by an ironic monitoring process that looks for the failure of our intention. Such monitoring can, when we are stressed or under mental load, actually promote the unwanted mental state.

Wardle and Beale (1988)

–          To investigate whether diets lead to overeating.

 

–          Assessed food intake at 4 and 6 weeks, Participants randomly assigned to diet group, exercise group or control group.

–          Study was conducted on 27 obese women.

–          Those who were ‘dieting’ ate more than those exercising.

 

–          Experimental design, which means manipulation could take place.

–          Random allocation to participants.

–          Lab conditions- high control

 

–          Small sample size

–          Lacks ecological validity.

Restraint Theory

This is where people restrain what they eat so they can diet but end up overeating.

Wardle and Beale’s reasons for overeating:

–          Counter regulation. Eating more after a high calorie intake.

–          Disinhibitant. Eating more because they’re being less strict on themselves.

–          The ‘What the Hell’ effect. Individuals decide its ok to break the diet more so if they’ve already broken it.

When restraining food the individual has to overcome impulses cognitively.

‘Cognitive Boundaries’ this is how much a person can eat before feeling full.

Process of restraint battles with ‘biological rhythms’.

Hermen and Mack 1975

–          Gave participants a pre-load food either high or low calorie.

–          Participants are left alone to do taste test in own time.

–          Key factor- they know how much they eat.

 

–          Dieters ate more in the taste test if they had a high calorie preload.

 

(note participants were told they were taking part in a taste preference test.)

 

 

Extra notes-

 

The Minnesota Starvation Experiment

Wardle and Beale

Ruderman and Wilson (similar to Hermen and Mack)

 

Operant Conditioning

Operant conditioning is the distribution of rewards and punishments. Behaviours which produce positive consequences such as compliments and attention are more likely to be repeated.

An example of this would be schemes such as ‘Weight Watchers’ and ‘Slimming World’ where individuals attend meetings and have to follow strict diets. At the meetings the individuals will get weighed and if they’ve lost weight, the rest of the group will distribute the positive comments, encouraging the individual to lose more weight.

This leads on to…

Social Support

This is where people tend to eat less if there are more people around them. If an individual is surrounded with people who are supportive about dieting, then they won’t want to eat as much.

Miller et al (1997)

Conducted a meta-analysis of diet, exercise and diet + exercise weight loss programmes found that the long-term success rate was greater for the diet plus exercise cohort.

Assignment 1- ‘Outline and evaluate factors influencing attitudes to food and eating behaviour, for example cultural influences, mood, health concerns.’ (24 marks)

1. Outline 2 factors (choose from culture, mood or health) that influence attitudes to food.  Provide examples.

-mood: overeating or under eating when depressed/distressed

-culture: eating what our parents do when we’re younger

        2. Explain the psychological theory behind these factors, e.g. Health models (TRB/TPB); Social Learning Theory; conditioning; biological responses; etc.

-overeating or under eating when depressed: this is a biological response.

-eating what our parents do: this tends to happen more when we are younger. Then, as we grow up and start making our own decisions, our attitudes towards food change from that of our parents. This is because of the Social Learning Theory (Bandura). This suggests we learn behaviours through ‘modelling’: observing other people and learning how the behaviour is performed. This is also due to conditioning. Children eat what their parents eat because they see them do it, therefore learn to associate what they eat with being a good thing.

3. Outline supporting studies – at least one in detail.

Social Learning Theory- Bandura, The Bobo Doll experiment

This experiment used children between the ages of 3 and 6 from Stanford University Nursery School. 36 boys and 36 girls took part in the experiment, and one male adult and one female adult were the role models.

Under controlled conditions, Bandura arranged for 24 boys and girls to watch a male or female model behaving aggressively towards a toy called a ‘Bobo doll’. The adults attacked the Bobo doll in a distinctive manner – they used a hammer in some cases, and in others threw the doll in the air and shouted “Pow, Boom”.

Another 24 children were exposed to a non-aggressive model and the final 24 child were used as a control group and not exposed to any model at all.

The researchers pre-tested the children for how aggressive they were by observing the children in the nursery and judged their aggressive behavior on four 5-point rating scales. It was then possible to match the children in each group so that they had similar levels of aggression in their everyday behavior. The experiment is therefore an example of a matched pairs design.

Over eating/under eating

Garg et al (2007) got participants to watch a funny film (Sweet Home Alabama) or a tear jerker (Love Story) whilst the researchers watched the participants choice of snacks; either popcorn or grapes.  Those watching Love Story consumed a third more popcorn than the other group whilst those watching Sweet Home Alabama ate more grapes. 

Low mood seems also to influence binge eating behaviour. Davis et al (1988) showed that low mood often preceded binge eating in bulimics.  The same seems to apply in those with no known eating disorder.  Students were asked to record their mood and eating habits over a two week period.  Days that included binge eating tended also to be days of low mood, but significantly, binge eating did nothing to improve mood afterwards.  So although we may binge when down it seems to do little to make us feel better.

4. Outline challenging studies

Mood- over eating or under eating

Objective:

To investigate whether negative mood and unbalanced nutrition style (fat rich/carbohydrate low) synergistically trigger binge eating in overweight and obese binge eating disorder (BED) patients.

Methods:

After  following an unbalanced or a balanced nutrition plan for three days, participants’ food intake in a taste test was measured. During the taste test, participants were either in a negative or a neutral mood that was induced through a guided imagery task.

Participants:

Sixty-nine overweight and obese women with BED (mean age: 36.7 years, mean body mass index: 32.8 kg/m2).

Measurements:

Eating behaviour was assessed by measuring the amount of eaten food during the taste test. Visual analogue scales were used to assess negative effect, tension, urge to eat, and hunger before and after the mood induction and after the taste test.

Results:

Negative mood and unbalanced nutrition had neither a combined synergistic effect nor separate additive effects on the amount of food intake. Negative affect and tension decreased after the taste test in the negative mood group.

Conclusion:

Negative mood does not always enhance the risk of binge-eating behaviour. Fat-rich, carbohydrate-low nutrition style did not influence food intake during a taste test. This finding questions the role of this specific nutrition style as a crucial factor in promoting binge eating. If replicated, these findings are important, since they could guide development of treatment protocols.