A small study suggests that men are better able to resist food cravings than women, which researchers say could partially explain why more women than men are obese, and why women are more prone to overeating when they’re under emotional stress. In a new brain-scan study, researchers flashed tasty food in front of men and women who hadn’t eaten anything in at least 17 hours. Both were told to fight their hunger, but only men showed a drop in activity in brain regions involved in emotion and motivation [CNN]. However, some researchers say that it’s risky to generalize based on a study with just 23 test subjects.
In the study, which will be published in Proceedings of the National Academy of Sciences, researchers engaged their volunteers in a somewhat torturous experiment. They first surveyed the volunteers about their favorite foods: Did they favor pizza, chocolate cake, burgers, or fried chicken? Then they were asked to fast overnight. When they returned to the lab the next day, the subjects got PET brain scans while being subjected to a barrage of craving-inducing stimuli. They looked at pictures of their favorite food, smelled its aroma wafting in from the next room, and even tasted it with cotton swabs placed on their tongues.
The volunteers were given three brain scans: One without the food stimuli, one with the food but no instructions, and a third when they smelled and stared at the food but were told to suppress their desire for it. After the men were told to resist their cravings, there was far less activity in regions of the brain called the amygdala, hippocampus, orbitofrontal cortex and striatum. All of these have been linked by other studies to “emotional regulation” and memory activation – suggesting that the men were retrieving their memories of the desired food less – perhaps making them less affected by the thought of it [BBC News]. The women’s brain activity was about the same as when they weren’t trying to suppress their cravings.
Lead researcher Gene-Jack Wang says the findings may partially explain different dieting outcomes: “The decreased inhibitory control in women could underlie their lower success in losing weight while dieting when compared with men…. We have seen in clinical studies that men following a diet are able to lose about 10 per cent of their weight on average over a three-month period, whereas women manage a decrease of only about 5 per cent” [Telegraph], he says. Other researchers suggest that female dieters looking for a lesson in this study should try to minimize their exposure to temptation, by avoiding junk food aisles in the grocery store, for example, and not walking past the Dunkin’ Donuts shop.
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