M&Ms and Evolution
For most of history, our ancestors have resorted to gluttony
as a means of survival if they sensed hard times ahead. As a result, our modern
day instincts are still hardwired to tell us to consume more calories in
preparation for times of scarcity, even despite an abundance of food. There are
pressures of life surrounding the laboratory. These stresses can follow you
home from work or vice versa, affecting you externally due to things like
seasonal changes or financial strain. A recent NPR
article noted people who are down in the winter or stressed out because of
their economic situation can experience periods of weight gain due to a higher
calorie diet.
Of course, it makes sense to put away something extra,
especially if the outlook is bleak for future meals. According to the article, “That
response, while perfectly suited for prehistoric times, is maladaptive today, when
more people in wealthy countries such as the United States are dying from
diseases related to obesity rather than starvation.”
The article chronicled researchers in a study as they
surveyed 121 college student using M&Ms and well-phrased sentences. Volunteers
were given a bag of M&Ms -- pretty much a dream-come-true if you share my
addiction to the little candies. Researchers first informed the volunteers that
some of the M&Ms were “high calorie” and some were “low calorie,” and “then
exposed the volunteers to unconscious signals -- words that indicated harsh
environmental conditions such as ‘survival,’ ‘withstand,’ ‘persistence,’ ‘shortfall,’
‘struggle’ and ‘adversity.’” It was soon discovered that, when subjected to the
cautious or otherwise foreboding language, the “high calorie” M&M-eating
volunteers “ate nearly twice as many” as their “low calorie” counterparts.
“High calorie foods, which are useful when resources are
scarce, are consumed in larger quantities when an environment is perceived to
be harsh, whereas low-calorie foods are consumed in smaller quantities” (Sic.) said
University of Miami researchers, Juliano Laran and Anthony Salerno. Which
explains why, when prompted in a second survey to feel the additional pressure
of limited resources, the volunteers ate even more of the “high calorie” candy.
Have you noticed some extra unwanted pounds lately? Do your
laboratory co-workers tend to change their diet with the seasons? The good news
is that it might not be our fault -- at least, not entirely -- but rather the impact of evolution that
hasn’t quite caught up with modern society yet. As researchers wrote, “The key
is to understand that the choice of unhealthy food is not always the result of
a willingness to indulge but can sometimes be the result of exposure to
information suggesting environmental harshness.”