Why do we eat junk food during the Christmas holiday period?

Most of us eat junk foods such as donuts, french fries, and soda. Consuming these types of food is associated with adverse health problems such as obesity, diabetes and cardiovascular diseases. So, what motivates us to eat junk food?

The answer, of course, is that our reasons for eating any food vary. For example, we might sometimes eat a chocolate cake for pure pleasure. Yet, at other times we might eat it just to please our friend who is celebrating their birthday.

The many types of motivations for unhealthy eating
According to self-determination theory, our reasons or motivations for engaging in any behavior differ along a continuum. At one end of the continuum, we find the self-determined motivations, which refer to behaviors motivated by inherent pleasure (e.g., enjoying the taste), important values and lifestyle (e.g., a lifestyle of low physical activity) as well as personal goals (e.g., eating to help social connection). At the other end, we have the non-self-determined motivations indicating behaviors pursued because of an internal sense of pressure (e.g., eating comfort food to reduce stress), external pressures (e.g., pressure to eat birthday cake) or unclear and ambiguous reasons (e.g., no clear reason).

Our reasons for eating junk food change during the holidays
In our study, we examined these types of motivations in relation to eating unhealthy and junk food. Understanding these motivations for unhealthy eating is important, because when individuals feel self-determined to engage in a behavior, they are more likely to persist in it.  
Since eating junk food is common and normalized during the Christmas holiday period, this time of the year was chosen for the study. Participants from the United States were followed across time and filled out our questionnaires one month before, during, and one month after the Christmas holidays.

Interestingly, we found that some types of motivations for unhealthy eating fluctuated over time, while others stayed stable. During the holiday period, individuals ate unhealthy food because they thought it was important, they wanted to avoid feeling guilty, and they felt pressured by other eating partners. They were also less confused about what motivates them to eat unhealthy food compared to before and after Christmas. So it seems like unhealthy eating was highly salient during the holiday season, and external pressures were playing a strong role. These results show that the social context in which we eat has a strong impact on our reasons for eating unhealthy food.

Unhealthy eating is more persistent when it is part of our habits
We also looked at how each type of motivation predicted the amount of unhealthy food individuals consumed. We found that four types of motivations (i.e., values and lifestyle, internal sense of pressure, external pressures and ambiguous reasons) were linked to higher levels of unhealthy food consumption. However, only important values and lifestyle consistent with junk food consumption predicted more unhealthy eating at all times (i.e., before, during and after the holiday period). So, although both self-determined and non-self-determined motivations are associated with eating more junk food, it is when unhealthy eating is part of a person’s important values and lifestyle, that junk food consumption is consistently higher.

How do we feel about our motivations for unhealthy eating?
These motivations refer to internal thoughts and feelings. So what’s their relationship with psychological well-being?

We found that when individuals ate unhealthy food because they found it personally relevant and necessary in a given context, they felt good psychologically. However, if they ate junk food for an unpleasant reason such as a pressure they put on themselves, or if they really couldn’t find a good reason for doing so, they experienced lower psychological well-being. That is consistent with the self-determination approach.  But intriguingly, even when feeling that unhealthy eating was part of one’s habits and values increased junk food consumption, eating junk food for this reason was associated with lower well-being.

• In sum, this study challenges the narratives of individual blame for unhealthy eating.  It shows that the social context in which we eat influences our reasons for unhealthy eating. In turn, our motivations for unhealthy eating are differently associated with how much junk food we consume and how we feel psychologically. The diversity of motives associated with healthy eating, and seasonal changes in those motives, invite people and practitioners who are interested in promoting healthy eating to explore the self-determined or non-self-determined motives for the actions at the time.

   -  By Nada Kadhim

Full reference: Kadhim, N., Amiot, C. E., & Louis, W. R. (2020). Applying the self‐determination theory continuum to unhealthy eating: Consequences on well‐being and behavioral frequency. Journal of Applied Social Psychology, 50, 381-393. https://doi.org/10.1111/jasp.12667