Gender Differences in Brain Activation by Food Stimulation

The increasing prevalence of obesity worldwide and associated morbidity and mortality highlights the need to understand the neurobiological and functional mechanisms underlying eating behaviors. Gender is a relevant factor since women are reported to have higher rates of obesity than men. To tap into the neurobiological underpinnings of eating behavior, we developed a food stimulation paradigm to be used for imaging and showed that the presentation of food that could not be consumed in normal weight subjects was associated with increased metabolic activity in the orbitofrontal cortex, which is a brain region involved with conditioning, salience attribution, and motivation. Women had greater activation in the anterior prefrontal and the orbitofrontal cortex than men during food stimulation. Using the same food stimulation paradigm, we found blunted activation of brain regions involved with inhibitory control in women when compared with men, which suggests a possible neurobiological mechanism for the gender differences in this behavior. Understanding the mechanism(s) contributing to gender differences in overeating behaviors may provide a scientific basis for pharmacological and behavioral approaches to its prevention and treatment.