Why our brain just can not resist the mixture of fat and carbohydrates

Why do people prefer foods with fats and carbohydrates?

Certain foods, such as fast foods, which combine fats and carbohydrates, particularly affect the reward system in our brains. As a result, we eat much more, which can lead to overweight and obesity.

Researchers at the internationally acclaimed Yale University found in their current research that a combination of fats and carbohydrates in food leads to excessive food intake. The physicians published the results of their study in the English language journal "Cell Metabolism".

Fast food affects the brain, so we prefer high-fat and carbohydrate foods, and often eat too much of it. (Image: Alexander Raths / fotolia.com)

Which foods contain many fats and carbohydrates?

In natural form, there are actually no foods that combine a high proportion of fats and carbohydrates in itself. Either foods contain many fats, such as nuts or they contain many carbohydrates, such as potatoes or cereals, explain the experts.

The reward system is outwitted by fast food

The brain develops a stronger craving for nutritious foods. So-called highly processed foods often consist of carbohydrates cooked in fat and coated or flavored with sugar. Such foods confuse the regulatory mechanism and the reward system in our heads. This in turn affects our food intake. Such foods actually have a greater impact on the reward system of the brain, which leads us to prefer fast foods over healthier snacks, the researchers say. For example, if you want to eat a banana instead of potato chips in front of the TV, but your brain is more used to fast food, it will prefer the greasy but nutrient-poor potato chips.

Subjects had problems with the calorie assessment

The fat-carbohydrate combination affects striatal neuronal circuits in the brain's prefrontal cortex more than a sweeter or more energetic diet or a larger portion of food. Participants were very good at estimating how much calories they could get from fat, but they had problems estimating the amount of very unhealthy carbohydrate calories, study author Dr. Dana Small from Yale University. At the same time, food that is rich in fats and carbohydrates automatically contains more calories.

Assessment of nutritional value should lead to adaptive decisions

The study shows that when the two nutrients are combined, the brain appears to overestimate the energetic value of the food, the expert adds. If foods contain such a combination, according to Dr. Small manipulated by eating innate signals of the body. The biological process, which regulates the association of food with its nutritional value, has evolved in the course of evolution to accurately estimate the value of a food so that organisms can make adaptive decisions. For example, a mouse with low-energy food should not risk running outside and exposing itself to a predator, the researchers explain.

Over 200 participants were examined for the study

The current study looked at more than 200 adult volunteers with a normal BMI. Subjects were brain-scanned while displaying photos of known snacks containing mostly fat, sugar or a combination thereof. They received a limited amount of money they could provide for the different foods. The subjects offered the most money for the fat and carbohydrate rich food. This suggests that this type of food was the most attractive to the participants. The measurements of brain activity showed that a combination of fats and carbohydrates activates the brain areas of the reward system more intensively compared to other foods, the researchers say.

Wrong diet leads to obesity

In nature, foods rich in fats and carbohydrates are very rare and they tend to contain fiber, which slows down the metabolism, the experts explain. In contrast, processed foods very often show a high fat and carbohydrate content. This has also been reflected in the bids of the subjects. Apparently, the so-called reward signals superimpose our satiety, which has the consequence that sufferers often develop obesity.

The typical western diet is very unhealthy

A so-called Western diet is virtually full of fatty and sugary foods, such as burgers, French fries and sodas. The health effects of such a diet range from obesity, high blood pressure and diabetes, to heart disease, colon cancer and dementia. (As)