People are satisfied with small portions when they are matched with an additional reward.
Researchers from the University of Arizona and the University of Southern California (USC) carried out functional magnetic resonance imaging (fMRI) studies to find out whether the brain responds to the "Happy Meal" concept of a small toy, gift card or lottery ticket in the same way it does to a mouthwatering burger or pizza laden with cheese.
The findings offer clues to why people overeat and how they can be just as happy not eating.
In a series of experiments, participants identified choices with various foods and incentives while researchers collected neuroimaging data with fMRIs.
Prize reward is as tempting as food
The researchers found that most children and adults chose a half-sized portion paired with a toy or monetary prize over a full-sized portion without a toy or monetary prize. The price of the two options was the same.
The results showed that the combination of a half-sized portion and a non-food premium activates similar areas of the brain as the full-sized portion alone. The area affected is the striatum, which is associated with reward, desire and motivation.
They also found that people were strongly motivated to choose half a burger or pizza even if they were hungry, and they did not compensate by eating more calories later.
Moreover, not only can a small prize motivate the healthier meal choice, but the very thought of getting the prize is more motivating than the prize itself. People were more likely to choose a smaller meal for the chance to win a $10 lottery than to gain a guaranteed reward. The premiums in the study were the chance to win $10, $50 or $100.
The authors write:
"Clearly, eating less is not fun for many people, and may even be a source of short-term unhappiness, as portion size restriction requires discipline and self-control. Yet, by combining one shorter-term desire (to eat) with another shorter-term desire (to play) that in combination also address a longer-term desire (to be healthy), different sources of happiness become commensurable."
How desirable the prize is also appears to affect motivation. Uncertain prizes seem to be highly motivating. A vague possibility of winning frequent flyer miles, as in "You could win" type offers, seems to be more effective than a probable contest where the odds are listed, such as "You have a 1 in 5 chance of winning."
This could be because possible premiums are more emotionally evocative than those offering certainty. This is seen in gambling or sports contexts, where the uncertainty of winning provides the added attraction of an emotional thrill.
The possibility of receiving a premium also evokes a state of hope while anticipating receiving the premium; this, in itself, is psychologically rewarding.
Offer non-food rewards for achievements
The findings imply that individuals can reward themselves for eating less food with non-food items. In other words, substitute rewards can be just as satisfying.
In light of these findings, the authors urge people to celebrate other achievements, like a job promotion, with something other than food. They also call on parents to reinforce children's achievements with non-food incentives.
Such strategies would help to decrease the linkage of good behavior with food intake, which can ultimately lead to overeating.
Antoine Bechara, professor of psychology at USC, believes this research suggests a win-win solution for both consumers and firms. More often than not, he says, restaurants and food manufacturers are interested in selling more food, not less.
The current findings provide "a simple but powerful solution to unite these two seemingly contradictory goals of selling more versus eating less."
An infographic that appears alongside the article suggests other examples of "new thinking" in avoiding overeating, including:
- avoiding describing an item as "healthy," as it encourages people to eat more of it
- using smaller, plainer plates, maybe even paper plates
- avoiding negative messages such as "don't eat cookies," as this can cause people to eat more of the item they want to avoid
- install mirrors in the kitchen: apparently, this discourages unhealthy eating.
Medical News Today recently reported that the concept of healthy food can lead to overeating.