A forthcoming article by University of Delaware associate professor Meryl Gardner finds there is more to stress eating than simply emotion, and in fact, thinking about the future may help people make better food choices.
"We were interested in the 'why,'" said Gardner. "Why when someone is in a bad mood will they choose to eat junk food and why when someone is in a good mood will they make healthier food choices?"
Gardner, a faculty member in UD's Lerner College of Business and Economics, with co-authors Brian Wansink of Cornell University, Junyong Kim of Hanyang University ERICA and Se-Bum Park of Yonsei University, found that a lot depends on one's perspective of time.
"In an evolutionary sense, it makes sense that when we feel uncomfortable or are in a bad mood, we know something is wrong and focus on what is close to us physically and what is close in time, in the here and now," said Gardner. "We're seeing the trees and not the forest, or how to do things and not why to do things."
To get at the "why," the researchers married the theories of affective regulation (how people react to their moods and emotions) and temporal construal (the perspective of time) to explain food choice.
They conducted four laboratory experiments to examine whether people in a positive mood would prefer healthy food to indulgent food for long-term health and well-being benefits and those in a negative mood would prefer indulgent foods to healthy foods for immediate, hedonistic mood management benefits.
In the first study, the researchers investigated the effect of a positive mood on evaluations of indulgent and health foods by examining 211 individuals from local parent-teacher associations (PTAs).
The findings indicated individuals in a positive mood, compared to control group participants in a relatively neutral mood, evaluated healthy foods more favorably than indulgent foods.
"We expect this is possibly because they put more weight on abstract, higher-level benefits like health and future well-being," said Gardner. "The remaining question was whether individuals in a negative mood would act differently."
Testing that question in a second study using 315 undergraduate students recruited from a large Midwestern university, the researchers found further support for their hypothesis that individuals in a negative mood liked indulgent foods more than healthy foods.
According to Gardner, the finding that people in a positive mood liked the more nutritious options and also liked the idea of staying healthy in their old age is consistent with the hypothesis that time construal is important.
"It suggests that positive mood makes people think about the future, and thinking about the future makes us think more abstractly," said Gardner.
The researchers were then left to eliminate goal achievement as an alternative explanation.
"Our manipulations of mood in the first two studies involved having participants read positive, negative or neutral articles," said Gardner. "As it turned out, the positive articles involved someone who had a great life and achieved lots of goals, and the negative articles involved someone who had a sad life and did not achieve goals. So the reviewers wondered whether the findings were due to the manipulation having involved goal achievement or the manipulation having led to different moods."
In order to prove the findings were not caused by differences in thinking about goal achievement, the researchers conducted a third study with an unrelated manipulation to show that mood not only affects evaluations of nutritious versus indulgent foods but also affects actual consumption.
Using raisins as health food and M&M's as indulgent food, Gardner said they altered participants' focus on the present versus the future along with their mood and measured how much of each food they consumed.
To get more insight into the underlying process, the fourth study focused specifically on the thoughts related to food choice, and differentiated concrete (taste/enjoyment-oriented) versus abstract (nutrition/health-oriented) benefits.
Ultimately, the findings of all the studies combined contribute to current research by demonstrating that individuals can select healthy or indulgent foods depending on their moods, an area previously under-represented in past clinical research on the role of healthy foods.
The findings also indicate the integral aspect of the time horizon, showing that individuals in positive moods who make healthier food choices are often thinking more about future health benefits than those in negative moods, who focus more on the immediate taste and sensory experience.
Finally, Gardner and her partners found that individuals in negative moods will still make food choices influenced by temporal construal which supports the idea that trying to focus on something other than the present can reduce the consumption of indulgent foods.
"If people in a bad mood typically choose to eat foods that have an immediate, indulgent reward, it might be more effective to encourage what we call mood repair motivation, or calling their attention to more innocuous ways to enhance their mood," said Gardner. "Instead of looking at nutrition and warning labels, try talking to friends or listening to music."