Reward systems in the brain That's why we can hardly say no to pie, chips and co

Why we can not keep our fingers off rich and carbohydrate foods

Actually, everyone knows that you should not eat too many chips, because they are known as fattening. Cream cakes and chocolate bars are certainly not among the healthy foods. Nevertheless, we can hardly say no to such food. Researchers have now discovered why this is so: Food rich in fat and carbohydrates activates certain brain areas particularly strong.

Sweet and hearty snacks are especially popular

Delicious chocolates, a piece of cream cake or a chocolate bar: For many people, the cravings for sweets already sets in, if they only think of the various treats. Others prefer to go for salty snacks like chips or fries. Apologies for feasting are also usually fast: stress in the job, a small reward for finished or sociable get-togethers. Researchers are providing people who can not keep their fingers off the unhealthy foods, now another excuse: The urge for high-fat and carbohydrate food is influenced by the reward system of the brain.

With cake, chocolate or even chips hardly anyone can say no. Researchers have now come up with an explanation for why this is the case: Through eating rich in carbohydrates and rich foods, the reward system in the brain is activated. (Image: dream79 / fotolia.com)

Hardly anyone can keep their fingers off unhealthy food

Although everyone knows that fries, cream pie, chips, candy bars and the like are thick and unhealthy, we can not keep our hands off it.

Scientists from the Max Planck Institute (MPI) for Metabolism Research in Cologne have now provided an explanation for this.

As the researchers report in a communication, foods that are high in both fats and carbohydrates have a particularly strong impact on the reward system in our brains.

Exception breastmilk

According to the experts, both fatty and carbohydrate-rich foods activate the reward system in the brain, albeit via different signaling pathways. When carbohydrates and fats come together in the food, this effect is exacerbated.

In nature, there are no foods that contain a high proportion of fats and carbohydrates: Either they are rich in fats, as in nuts, or rich in carbohydrates, as in the case of potatoes or cereals.

An exception is breast milk. "All mammals know breast milk", explains research group leader Marc Tittgemeyer from the Max Planck Institute for Metabolism Research, who conducted the study in cooperation with researchers from Yale University in Connecticut (USA).

"Breastmilk is likely to help us focus on high carbohydrate and fat rich foods, which we find particularly rewarding because it's vital to survival."

Game about food

The researchers wanted to know if people from different calorie sources more or less prefer existing food. To answer this question, 40 volunteers played food for a computer.

It offered foods high in fat or carbohydrates, as well as food that is both greasy and high in carbohydrates. In order to earn a food, the subjects had to outbid the computer.

Here, the willingness to pay was examined. For the high-fat and carbohydrate food, most of the money was offered. For the study participants, it was apparently the most attractive.

While playing, the researchers recorded the subjects' brain activity in a magnetic resonance tomograph.

The measurements showed that a combination of fats and carbohydrates activates the brain areas of the reward system more intensively than the other foods offered. This finding is consistent with the results of the game.

Reward is stronger than satiety

A reward that has contributed to human survival in evolution is destroying us in today's world of abundance.

"We are not meant to say no all the time. That's why we usually do not stop eating, even though we're full, "stresses Tittgemeyer. Obviously, the reward signals overshadow satiety - over-saturation and obesity are the consequences.

In addition, we just calculated the nutritional value of high-fat and high-carbohydrate food can hardly estimate: If the researchers asked the study participants to estimate the calorie content of the food offered, they succeeded in the high-fat or carbohydrate food relatively accurately.

On the other hand, they were often wrong with high-fat and carbohydrate foods. At the same time, food rich in fats and carbohydrates does not automatically produce more calories.

The results of the study were published in the journal "Cell Metabolism".

According to the experts, the findings could play an important role in the treatment of overweight people. Especially when eating becomes an addictive factor, the treatment of consumer behavior is of great importance and a fundamental step out of addiction. (Ad)