Take a glance at most magazines and blogs and you're more likely to see tips on how to staunch your appetite rather than how to make yourself want to eat more. Granted, weight loss tips (erroneous or not) tend to attract more clicks (and sales) given the thin ideal's continued reign over our psyches and beauty standards. But for some populations, the greater concern isn't eating less; it's making food (especially whole foods, like fruits and vegetables) more appealing so that you eat enough.
A population for whom the task of eating enough (or more) is most relevant is the elderly — particularly those in this community who live alone. Research shows that individuals who are over the age of 50 and consume most of their meals alone have poorer quality diets. One study found that older folks who were single and lived alone ate 2.3 fewer servings of vegetables on a daily basis. This wasn't the case for folks in the study who were partnered up.
Psychologists believe this decline in quality food consumption comes in large part from the lack of social influence on what and how much we eat — a phenomenon called the "social-facilitation effect." This phenomenon tends to work for better and for worse in terms of overall health. Social facilitation can make you eat more fruits and vegetables (and fewer helpings of dessert) if the majority of your friends (or family members) opt for a healthier eating regimen. Social facilitation can also make you eat more junk food if high-sugar, high-fat options are the go-to edibles consumed by your social groups.
If, however, you've got no one to eat with the social-facilitation effect cannot occur . . . or can it? A team of psychologists from Nagoya University decided to test some interventions that elicited the same effects of social facilitation without requiring anyone else (apart from the solo eater) to be present.
"We wanted to find out what the minimum requirement is for the social facilitation of eating," lead author Ryuzaburo Nakata said in a recent press release. "Does another person have to actually be physically present, or is information suggesting the presence of others sufficient?"
They asked 16 elderly adult volunteers between the ages of 65 and 74 to eat samples of popcorn alone. Some volunteers ate these samples alone in front of a mirror; others merely ate alone. Both groups were given the same amount of food and allowed to eat for the same amount of time (90 seconds). All volunteers were then asked to rate the tastiness of the popcorn via a variety of different measures (i.e., "How good is this popcorn?” “How do you feel about the quality of the popcorn?” “How much do you like this popcorn?” “How filling is the popcorn?” “How salty is this popcorn?” “How sweet is this popcorn?”). Despite having the same snack in front of them, the elderly adults who ate alone while looking at their own reflection rated the popcorn as tasting better — and also ate more of it — than the elderly adults who ate alone without gazing at their own reflection.
The researchers believed that the image of oneself eating served as its own social facilitation effect, encouraging the older adults to eat more simply by having their own selves eating to watch. To test whether this effect was unique to elderly populations, the researchers conducted the same experiment on two groups of younger volunteers. They found the same effect — irrespective of age, people who ate in front of a mirror liked the food they ate more and consumed greater quantities of it than those who did not have a mirror to look at.
And in one more study, the researchers invited 12 elderly adults to snack on soy beans. This time around, some were placed not in front of a mirror, but in front of images of themselves (taken during the study) eating the same food. These images also seemed to elicit a social facilitation effect, causing those who viewed them while eating to consume more food and rate it as tasting better than a control group who ate alone without any images to look at.
"Studies have shown that for older adults, enjoying food is associated with quality of life, and frequently eating alone is associated with depression and loss of appetite," Nobuyuki Kawai, another study author added in the press release. "Our findings therefore suggest a possible approach to improving the appeal of food, and quality of life, for older people who do not have company when they eat — for example, those who have suffered loss or are far away from their loved ones."
Intriguingly, eating in front of a mirror has also been found to achieve the opposite effects in previous studies. In 2015, for instance, Ata Jami of the University of Central Florida found that watching oneself eat junk food in a mirror reduces the amount of junk food consumed, as well as the perceived tastiness of that junk food. Nakata and Kawai note that the difference between previous studies and their own boils down to the types of food deployed in the studies: Prior research has looked at ways to reduce intake of unhealthy items (ice cream, cookies, pizza, etc.). Nakata and Kawai used popcorn (relatively healthy) and soy beans (healthy). So it seems that the desirability and "healthfulness" associations with food may play a strong role in whether watching yourself (or others) eat facilitates or reduces how good that food tastes and how much of it folks want to eat.
One could also argue that a mirror (or static) image of oneself eating simply draws more awareness to the self as we eat. As a result, we may be prompted by images of ourselves to be more mindful of what, exactly, we're doing. This wouldn't necessarily be attributable to social facilitation; rather, it would arise from prompts in our environment that drew our attention to our own behavior, enabling us to slow down and pay attention to what we're doing (eating). When we pay more attention to what we're putting in our mouths we're naturally inclined to appreciate its taste more, notice just how much we're eating, and also attend to whether what we're eating is truly good for us or not. This enhanced mindfulness may be a better explanation, then, for why in some cases watching oneself eat can increase the tastiness and volume of food consumed and, in other cases, reduce the tastiness and volume of food consumed.