Hunger Control Is Easier for Men and It’s All in the Brain
A new study published in the journal Proceedings of the National Academy of Sciences, showed women have more trouble resisting food than equally hungry men. Dr. Gene-Jack Wang, the lead researcher and a nuclear medicine specialist, used positron emission tomography (PET) scans to observe brain activity in 13 women and 10 men. After not eating for 17-19 hours, the volunteers underwent brain scans while they looked at images of their favorite foods. The researchers even wafted food smells throughout the room and subjects were given a taste of food with a cotton swab placed on their tongue.
The hungry volunteers had three brain scans. The first scan was after they had no instruction on how to react to food. The second was after they were told to resist their desire for food and the third was with no food in front of them. The women’s brain activity was the same even if they were suppressing their desire. They continued experiencing emotional cravings even when they were consciously able to feel less hunger and suppress the desire to eat.
The men, on the other hand, showed less activation in the amygdala, hippocampus, insula, orbitofrontal cortex and striatum regions of the brain when they tried to suppress the urge to eat. They were able to think about something else and those regions of the brain did not show activation.
These parts of the brain are involved in emotional regulation, conditioning and motivation. The Amygdala is the deepest and most primitive of brain structures and is involved with obsessive-compulsive disorders.
The marked difference between the activation in the women compared to the men shows that men may have better internal ways to control appetite. It is known that women have a harder time losing weight than men and are more likely than men to be obese. Women, more than men, also tend to overeat when presented with food or if they are under emotional stress. In this study the men showed a drop in activity in the brain when they tried to control their appetite. Women had no such drop.
In one study the men on a 3-month diet were able to lose 10% of their body weight, compared to women who only lose 5%, according to Dr. Gene-Jack Wang.
There is speculation that women have evolved to eat food when they see it to maintain body fat for healthy pregnancy. In early cultures the women had less access to food and were the last to eat (after the men) so they might have been driven to eat whatever they saw. Hormones also play a roll in women’s difficulty getting rid of extra adipose tissue and estrogen affects distribution of fat and appetite.
Since women who diet may respond more acutely to food "cues," this study shows that avoiding those cues may be helpful in staying on a diet. Unfortunately, women are usually the “food provider” of the family so they are dealing directly with the food stimulus throughout the day. That is another double whammy that dieters will need to find ways to handle.
The study was funded by the National Institute on Drug Abuse, the National Institute on Alcohol Abuse and Alcoholism, and by the General Clinical Research Center of Stony Brook University