The neurological benefits of being fat
Although there has been a push toward body-positive images in recent years, the labels of being “skinny” or “fat” still remain a large part of our lives. These body-positive images appear to be good for adolescents since they enable them to feel comfortable and happy in their bodies, no matter their size. However, recent neuroscience research suggests that having either high body mass index (BMI) or high visceral fat levels could lead to neurologically measurable increases in happiness and positive emotionality. Additionally, visceral fat is correlated to increased cortical mass, which is again correlated to increased intelligence and decreased stress. Although obesity may have its medical downsides, perhaps it lacks neurological ones.
In a recent study sponsored by the University of Minnesota, it was found that volumes in different regions of the brain can be related to adolescent BMI after controlling for age and other factors. In particular, overweight and obese adolescents had higher gray and white matter volume, which suggests poor control and increased motivation to eat. They also had increased personality trait differences in emotional reactivity and positive motivational drive.
Other personality measures have been shown to have associations with BMI as well. For example, having personality traits related to reward seeking was positively correlated with a higher BMI (r = −0.384, p < 0.001), illustrating that people with higher BMIs could potentially be happier when reaching rewards. Another systematic review of personality traits and obesity investigated the personality traits related to risk and reward, and found that traits such as “impulsivity,” “extraversion,” “conscientiousness,” “novelty seeking,” “persistence,” and “self-directedness” are positively correlated to overweightness, obesity, and eating behavior.
These traits in real life are generally regarded as positive and beneficial for an individual, and the positive emotionality associated with it may tell of happiness in general in their lives.
A study conducted in North Carolina showed that body appreciation and body image flexibility, defined as “openly engaging (versus avoiding) negative thoughts and emotions about the body in order to live life more fully,” were highly correlated, and lower BMI most strongly predicted positive body image. However, the study did not prove the converse. A higher BMI did not increase the difference between body dissatisfaction and positive body image. Consequently, although BMI perhaps influences personality traits and how one feels, a higher BMI and the thought of being “fat” does not actually decrease happiness.
However, although BMI is a telling metric for obesity, it is better used as a metric for determining risk of other diseases rather than for telling if a person is “fat.” A look at another metric, visceral fat, may help characterize the neurological effects of adolescents’ feelings about their body image.
Visceral fat, or body fat that is stored around the abdomen, was associated with increased brain cortical thickness.
A study conducted by the World Obesity Federation concluded that visceral fat, or body fat that is stored around the abdomen, was associated with increased brain cortical thickness. Increased cortical thickness has been linked to less stress and fewer stress related disorders as well as increased mindfulness, higher cognitive abilities, and intelligence. Visceral fat, like BMI, illustrated no negative neurological impacts of obesity.
So is being “fat” a bad thing at all, if it leads to being smarter and less stressed, with no reasonable negative impact on happiness? Perhaps not neurologically, though being obese definitely increases the risk for heart disease, diabetes, stroke, arthritis, and some cancers. However, as long as the media keeps telling us to be skinny, being fat will still be stigmatized.