Can Your BMI Affect Your IQ?
Common sense tells us that a healthy diet and regular exercise are important in maintaining a high level of physical ability. But do these factors have an effect on intellectual ability as well? According to some scientists, an individual’s Body Mass Index (BMI) can have a significant influence on cognitive function.
A study in the journal Obesity investigated the relationship between BMI and activity in various regions of the brain. The researchers found that those with high BMIs (obese individuals) showed less activity in the prefrontal cortex and the cingulate gyrus. The level of activity was higher in those with lower BMIs, which contributed to better performance on memory and executive function tests(1).
The superior performance wasn’t too much of a surprise, as the prefrontal cortex controls executive functions, judges the consequences of actions, and is involved in decision-making and other complex cognitive actions. The cingulate gyrus, meanwhile, is related to emotions, learning and memory. As a result, lowered activity levels in these areas caused by obesity can lead to intellectual impairments.
Most disturbing, though, is the fact that this phenomenon can begin while an individual is still young. An earlier study from the same journal noted that overweight children displayed "decreased visuospatial organization and general mental ability(2)."
Indeed, the researchers in the first study noted the gravity of the findings, saying, "these results further highlight the urgency to institute public health interventions to prevent obesity."
So while staying in shape may not be guaranteed make you smarter, it can only help.
The good news, though, is that maintaining a healthy BMI can be easy. Incorporating at least 30 minutes of physical activity into your daily routine and making intelligent nutritional choices are simple, painless steps that can go a long way toward bettering your body and mind.
Even making the switch from taking the stairs instead of the elevator and opting for a baked potato instead of french fries at dinner bring you one step closer to a healthier lifestyle and a sound body and mind.
SOURCES:
1. Nora D. Volkow, et al. Inverse Association Between BMI and Prefrontal Metabolic Activity in Healthy Adults. Obesity, 2008. (17)1, 60-65.
2. Yanfeng Li, et al. Overweight Is Associated With Decreased Cognitive Functioning Among School-age Children and Adolescents. Obesity, 2008. (16)8, 1809–1815
Post by: BrianWillett
February 23, 2009 - 7:56 am MDT at 7:56 am
Interesting!
February 23, 2009 - 8:07 am MDT at 8:07 am
I don’t know if BMI affects intellect, but other studies have shoved that obesity is more common among people with less education and of lower social "classes". I was pretty fat when I was younger, but I don’t think it affected my grades or my intellect. I was fortuntate to grow up in common middleclass familiy that valued education.
I think obesity is more linked to social and cultural aspects. And that makes it not surprising from a statistical standpoint that "stupid people" have higher BMI than "smart people".
Very interesting discussion though…but I don’t think this article says anything about reasons…just correlation between the two.
February 23, 2009 - 8:26 am MDT at 8:26 am
It effect the brains because the brains wont have alot of oxygen to develop better. But that is only one factor of the equation.
If you are obese you blood doesnt flow well around the body
February 23, 2009 - 9:24 am MDT at 9:24 am
Obviously, there will be other causes of lower intelligence, and obesity isn’t going to make someone completely ignorant. The study merely showed that those with higher BMIs had less brain activity in certain areas and that could hamper intelligence. In addition, it would be impossible to tell how smart someone could have been with a lower BMI.
April 26, 2009 - 6:30 pm MDT at 6:30 pm
This didn’t answer if BMI effects intelligence of if intelligence effects BMI.