Could a good mood make you eat more food?

‘Research has found emotional eaters tend to eat more when happy’, reports the Mail Online website.

The news is based on a small study looking at whether experimentally altering mood has an effect on the amount of calories a person eats.

The researchers examined the effects on what they describe as ‘emotional eaters’ – people who reported using food as a coping mechanism for emotions.

A group of 86 students, who said they were either emotional or non-emotional eaters, were shown TV and movie clips to evoke either a positive, negative or neutral mood. The researchers then assessed how much the students ate when provided with bowls of crisps and chocolate, as well as assessing their change in mood.

Emotional eaters who were shown the positive mood-inducing scenes significantly increased their food intake compared to emotional eaters shown the neutral mood-inducing scenes. However, the negative mood-inducing scenes had no effect on food intake of emotional or non-emotional students.

The common assumption is that emotional eaters eat more when in a negative mood, but this study provides very limited evidence to suggest that this may not always be the case.

However, because this experiment was based in a laboratory and researchers did not measure how hungry people were, even this finding should be viewed with caution. As ever, more and better research is needed if people with eating disorders or weight problems are to be helped effectively.

Where did the story come from?

The study was carried out by researchers from Maastricht University in The Netherlands and was funded by the Netherlands Organisation for Scientific Research. It was published in the peer-reviewed journal, Appetite.

The story was picked up by the Mail Online website and it was covered appropriately, although the limitations of the study could have been described in more detail.

What kind of research was this?

This was a laboratory study looking at the effect of experimentally influencing mood changes in a group of students reported to be emotional or non-emotional eaters, and then looking at the effect on their food and calorie intake.

The researchers say emotional eaters are thought to increase their food intake in response to negative emotions, but little is known about the effect of positive emotions on their food intake. Meanwhile, non-emotional eaters are not believed to change their intake levels in response to emotions, and they might even restrict food intake in response.

The main limitation of this research is that a study of a small, select population sample under experimental conditions can only provide very limited indications about the possible influence emotions may have upon the eating patterns of different people in daily life.

For example, if you thought that researchers could be measuring how much you were eating it could make you, perhaps unconsciously, reluctant to eat as much as you normally would. Alternatively, being in this type of study could make you nervous, leading you to eat more than you normally would.

What did the research involve?

The researchers recruited 86 psychology students in their second year at Maastricht University in the Netherlands who received credit points for their participation. The students were predominantly female (75%) and had an average age of 21.6 years (range 19 to 43).

The students answered a series of questionnaires to assess their mental health and eating behaviours. Emotional eating was assessed using a questionnaire called the Dutch Eating Behaviour Questionnaire (DEBQ). Students were asked, ‘Do you have a desire to eat when you’re feeling lonely?’ and provided answers on a five-point Likert scale that ranged from ‘never’ to ‘very often’.

The researchers then carried out a series of experiments in a laboratory setting that aimed to change the student’s mood. Students were randomly allocated to view clips from television or films that aimed to evoke either a positive, negative or neutral mood:

28 students were shown two clips to evoke a positive mood. Firstly, they were shown a scene from the television series Mr Bean (which showed Mr Bean struggling to copy answers from his neighbour during an exam). The second clip was taken from the movie ‘When Harry Met Sally’ which showed the famous scene where Meg Ryan’s character simulates an orgasm in front of other diners in a restaurant.
28 students were shown one negative clip from the film ‘The Green Mile’, which showed an innocent man being executed.
30 students were shown part of a documentary about fishing to evoke a neutral mood.

The students were told to give in to the emotions the clips evoked, and were presented with bowls containing 191g of chocolate (white, milk and dark, equivalent to 1,000 kcal), 225g of salted crisps (1,229 kcal) and 225g of ketchup crisps (1,217 kcal). The bowls were weighed before and after the experiment to determine the amount of food eaten and calorie intake.

The students were asked to assess their mood using a visual analogue scale (this is essentially a straight line – where the far left of the line represents poor mood and the far right represents very good mood) at five points during the experiment:

before the experiment began
immediately after watching the television or movie scenes
5 minutes after the experiment
10 minutes after the experiment
15 minutes after the experiment

The students were told when entering the laboratory that they were taking part in an experiment on the effect of movie clips on taste perception.

The researchers analysed their results using validated methods and adjusted the results for gender, body mass index (BMI), external eating and dietary restraint as assessed by the DEBQ, and negative mood as assessed by the Positive and Negative Affect Schedule (PANAS).

What were the basic results?

Overall, there was no significant difference between emotional eaters eating more than non-emotional eaters who were shown positive, negative or neutral clips.

When looking specifically at only the emotional eaters:

those shown the positive mood-inducing scenes significantly increased their intake of food compared to those shown the neutral mood-inducing scenes
there was no difference in food intake between students shown negative mood-inducing scenes and those shown neutral or positive mood-inducing scenes

How did the researchers interpret the results?

The researchers concluded that self-reported emotional eaters respond in a different way to emotions than non-emotional eaters. They say that emotional eaters ate more in a positive mood compared to a neutral mood, whereas non-emotional eaters ate about the same amount in both conditions.

In discussing the results, the researchers say the findings could be of value for the treatment of obesity.

Conclusion

Overall, this small study provides very limited evidence to suggest emotional eaters eat more when feeling in a positive mood. There are several limitations to this study, some of which are noted by the researchers. These include the facts that:

the laboratory setting may not be an appropriate setting to test emotional eating with different mood feelings. It is possible that students felt uncomfortable in this setting and limited their food intake as they were being watched
the students were told they were partaking in an experiment of taste perceptions, so may have been inclined to eat more than they normally would have because of what they were told the study was looking at
no hunger measurements were taken during the study and how hungry each student was could have greatly affected the results
there was no group included in the study that did not eat, so it is not possible to say from the findings that the changes in mood were due to food intake
all of the participants were students, so findings may not be the same as if the same experiments were carried out in different groups who report being emotional eaters

To draw firmer conclusions about the effects of mood on emotional eating, larger studies of different groups are required that carry out experiments in more natural environments.