Mood and Eating Behaviour

Hunger is associated with increased arousal, vigilance and irritability. Studies have shown that people who are stressed or depressed increase the carbohydrate and fat content of their meals. This is associated with better mood and more energy. 

The Serotonin hypothesis: Carbohydrates such as chocolate contain the amino acid tryptophan. This is used by the brain in the manufacture of the neurotransmitter serotonin. Low levels of serotonin are associated with depression and it has been proposed that people with stress or depression take in more carbohydrates because this increases serotonin. 

However, the presence of a small amount of protein prevents the tryptophan from entering the brain and so serotonin will not increase. This means the serotonin hypothesis is unlikely to explain the effects of high carbohydrate diets.

The Opiate hypothesis: Examples are enkephalin and beta-endorphin. They are released from neurons and act at synapses with opiate receptors. Opiates are similar to the opiate drug heroin. This is highly addictive which can also produce pleasurable feelings, therefore it seems likely that the brain's opiate pathways are part of our reward system, a network of pathways that control out feelings of pleasure and reward. Opiate drugs increase food intake and the perceived tastiness of food. 

Binge Eating

- Research has shown that individuals with bulimia nervosa complain of anxiety prior to binge.
- Studies show that before a binge, bulimic individuals have more negative mood states than one hour before a normal snack or meal.
- In studies, binge days were associated with low moods.
- Low moods may make binge-eating more likely.
- Many people tend to comfort eat - supported by Garg et al (2007)

Reinforcement

- Although binge-eating can offer gratification, reinforcement is feeling and studies report a drop in mood immediately after the binge.
- Chocolate has been seen as the ultimate comfort food. Attitudes towards chocolate are influenced by  claims that it can lift our mood - supported by Parker et al (2006)

Binge-Eating Disorder - Supported by Wolff et al (2000)  

Mood and Eating Behaviour - Studies

Garg et al (2007) 

Procedure

- Observed the food choices of 38 participants who watched either a funny movie or sad one.
- Participants were offered buttered popcorn and seedless grapes.

Findings

- Those watching the sad film consumed 36% more popcorn than those watching the funny film.
- People watching the funny film ate far more grapes than the other group.
- People who feel sad want to 'jolt themselves out of the dumps' and are more likely to want a anck that will give them a sudden rush of euphoria.
- Happy people choose healthy foods.

When people were presented with the nutritional value beforehand, consumption of unhealthy foods dropped dramatically. 

Parker et al (2006)

Found that, although chocolate has a slight antidepressant effect, when consumed as an emotional eating strategy, it is more likely to prolong rather than alleviate the negative mood. 

Wolff et al (2000)

Procedure

- Investigated differences between 20 female bing eaters and 20 female normal eaters.
- Daily measures of mood, coping and eating behaviour were self-recorded for three weeks.

Findings

- Binge group reported more stress and negative moods but stress levels were similar on their binge and non-binge days.
- Negative mood states are related to abnormal eating practices such as binge eating.