Got cravings? New research suggests our snacking habits and Body Mass Index aren’t just related to hunger. Instead, they have a lot to do with our brain activity and self-control Nucleus accumbens response to food cues predicts subsequent snack consumption in women and increased body mass index in those with reduced self-control. Lawrence, N.S., Hinton, E.C., Parkinson, J.A., et al. Schools of Psychology, Cardiff University, Park Place, Cardiff CF10 3AT, UK; Schools of Psychology, University of Exeter. Perry Road, EX4 4QG, UK. Neuroimage, 2012 Jul 6..
The study, which will appear in the October issue of the journal NeuroImage, involved 25 young, healthy females with BMIs ranging from 17 to 30. (Researchers chose to test women because they’re generally more responsive than men are to food-related cues.) Processing of food pictures: influence of hunger, gender and calorie content. Frank, S., Laharnar, N., Kullmann, S., et al. MEG-Center, University of Tübingen, Tübingen, Germany. Brain Research, 2010 Sep 2;1350:159-66. Gender and weight shape brain dynamics during food viewing. Toepel, U., Knebel, J.F., Hudry, J., et al. The Functional Electrical Neuroimaging Laboratory, Department of Clinical Neurosciences, Vaudois University Hospital Center and University of Lausanne, Lausanne, Switzerland. PLoS One, 2012;7(5):e36778.. After not eating for six hours, women viewed images of household objects and different food items (licking the computer screen was not allowed) while MRI scans recorded their brain activity. Researchers asked women to rate how much they wanted the food they saw and how hungry they were, then presented participants with big bowls of potato chips and counted how many they popped into their mouths.
Results showed that activity in the nucleus accumbens, a part of the brain associated with motivation and reward, could predict the amount of chips the women ate. In other words, the more activity there was in this part of the brain, the more chips women consumed.
And perhaps the biggest surprise: The number of chips women ate wasn’t at all related to their reported feelings of hunger or snack cravings. Instead, self-control (as measured by a pre-experiment questionnaire) had a lot to do with how much crunching women did. Among the ladies whose brains lit up in response to images of food, those with high self-control tended to have low BMIs and those with low self-control generally had high BMIs.
Dr. John Parkinson, a senior lecturer in psychology at the University of Bangor and one of the study authors, said the results mimicked what often happens in real life. "In some ways this is the classic buffet party phenomenon where you tell yourself you shouldn't binge on the yummy snacks, but you "can't help yourself" and end up feeling guilty," he wrote in an email.
The results from the study support other research that suggests certain people are more sensitive to the sight of food and therefore more likely to be overweight (though it’s still not clear whether our brain response to images of food is learned or innate) Gender and weight shape brain dynamics during food viewing. Toepel, U., Knebel, J.F., Hudry, J., et al. The Functional Electrical Neuroimaging Laboratory, Department of Clinical Neurosciences, Vaudois University Hospital Center and University of Lausanne, Lausanne, Switzerland. PLoS One, 2012;7(5):e36778.. Now the researchers are working on computer programs that will help train our brains to respond to food differently. So, ideally, Snickers bars will look less tempting and it’ll be easier for users to maintain a healthy weight.
To find out more about the way our brains influence our eating habits, scientists also need to consider other people besides young, healthy women. Lead researcher Dr. Natalia Lawrence, a senior lecturer in psychology at the University of Exeter, mentioned some opportunities for future research. “It would be interesting to study a group of bulimics with low BMI and low self-control; presumably they engage other (e.g. compensatory) mechanisms such as working out a lot or avoiding temptation in the first place,” she wrote in an email.
There’s a lot left to learn about the relationship between the brain and eating behavior. Right now researchers are still unsure how different brain training techniques will affect our self-control and food cravings. Who knows? Maybe soon we’ll use our Tetris skills to help keep our weight down.
Would you try playing a computer program to control your weight? Let us know in the comments below.
Photo by Caitlin Covington