Last week's Calorie Balance Conundrum blog sparked some discussion on whether we have complete control of our calorie intake. Some readers disagreed with the presented study's claim that the combination of our environment and our biology makes balancing calories almost impossible.  Well, here's another recent study that suggests a biological inability to control eating behaviors.

The study, published in The Proceedings of the National Academies of Sciences,¹ asked 23 men and women about their favorite foods. These men and women then underwent a 20 hour fast. After the fast, they were presented with their favorite foods and allowed to smell or taste, but not eat them. The study subjects were then told to inhibit, or restrain, their desire to eat the food while a PET scan examined their brain activity.

The researchers found that in the men, but not the women, food stimulation with inhibition significantly decreased activation in the parts of the brain involved in emotional regulation and motivation. Decreased activation in these parts of the brain, with inhibition, in men was also associated with decreased self-reported hunger. Thus, researchers suggest that certain regions of the brain do process the conscious awareness of the drive to eat and that women have a lower ability to suppress hunger/desire for food because of lack of decreased brain activation with inhibition. Furthermore, the researchers suggest that women's inability to inhibit themselves might be a contributing factor to gender differences in obesity.  

Still convinced that we do have control? Post your thoughts.

¹ Wang , G.J. (2009).Evidence of gender differences in the ability to inhibit brain activation elicited by food stimulation. Proceedings of the National Academies of Sciences of the United States of America doi:10.1073/pnas.0807423106.