Good news for anyone who has never been able to walk by a basket of piping hot french fries and not been able to resist taking one — it's because your brain is programmed that way!
A new study published in the scientific journal Cell Metabolism has shown that foods that contain both carbs and fats, like those very tasty french fries, are almost irresistible to most people. Basically the reward center of the brain — the striatum — sees more dopamine released to it when you consume fats and carbs together. Dopamine is the neurotransmitter that controls rewards and pleasure.
The study, conducted by researchers in the U.S., Germany, Switzerland, and Canada, said that it all dates back to when people began to farm and raise their own food. They would always choose the foods that were the most carb and fat heavy, because that helped ensure a longer survival and peak energy.
206 people received brain scans as they were shown pictures of foods that were either high in fat, high in sugar or high in a combination of fat and carbs. They were even given a limited amount of money to bid on the foods they'd most like to eat. Not surprising, the subjects who were studied were willing to pay more for foods that were high in carbs and fats, often labeling them as their "favorite" foods.
"The biological process that regulates the association of foods with their nutritional value evolved to carefully define the value of a food so that organisms can make adaptive decisions," says senior author Dana Small, director of Yale University's Modern Diet and Physiology Research Center. "For example, a mouse should not risk running into the open and exposing itself to a predator if a food provides little energy."
"Foods containing fats and carbohydrates appear to signal their potential caloric loads to the brain via distinct mechanisms," she said. "Our study shows that when both nutrients are combined, the brain seems to overestimate the energetic value of the food."
So while it may make you feel better to know the reason why it's so easy to reach for the hot fries, doughnuts and pizza is because our brains are programmed that way, we know that foods that combine carbs and fats are not the healthy choice.
The researchers are hoping this study will help them understand the causes of obesity and food addictions, and why people eat even when they aren't hungry. They're also hopeful the study will also help them better understand issues with weight loss. At least we all know that we have our brains to blame when we give in to our cravings!