Scientists have found that eating tasty food decreases the activity of brain cells that control hunger and thirst. In other words, the more you eat, the more you want to eat. That’s why it can be so hard to say no to a second slice of cake with tea, even after a hearty lunch, scientists say.
The journal Nature reports the results of a study conducted by a group of scientists led by Scott Sternson of the Janelia Research Campus in Ashburn, Virginia. In experiments on mice, they identified an area of the brain that contains cells (neurons) responsible for food and water consumption. Activating the neural network in this area suppresses hunger and thirst. And vice versa: blocking it causes mice to continue eating and drinking even when they are fully satiated.
The researchers offered mice different drinks while monitoring the activity of “abstinence neurons. A slight decrease in activity was recorded when the mice drank water or bitter drinks, and a much greater decrease occurred when the mice were given tasty liquids – vanilla-flavored, for example. Scientists believe that a neural network is designed so that a pleasant taste makes the brain want more. In 2019, the journal Science reported the results of a similar study. The authors, who also worked with experimental mice, discovered that the brain can be programmed to overeat: this is exactly what happens when you eat foods high in fat and sugar.
A group of scientists at the University of North Carolina at Chapel Hill, led by neurobiologist Garrett Stuber, studied the changes that occur in the brain during obesity. They compared the behavior of neural networks in the brains of living normal-weight and overweight mice immediately after a meal: the animals were given calorie-rich sweet water. The brains of non-obese mice responded to sugar by increasing the activity of neural networks: the cells seemed to send a “stop” signal, forbidding the demand to continue the feast. But as the mice got more and more sugar, they began to gain weight – and the neural networks in their brains became less and less active, the researchers found. By the 12th week, the cells were about 80% less active in responding to the sweet drink. However, this study does not specify which exact changes led to the loss of neural network activity: a sweeter diet or direct weight gain, notes neurologist Randy Silie of the University of Michigan, who was not involved in Stuber’s work. Siliv does not rule out the possibility that the food itself was an important factor in the mice’s behavior. “You probably don’t know what rodent food tastes like,” says the scientist. “I’ve tasted it, it’s just disgusting. It’s dry, salty, tasteless garbage.”
At the same time, the fatty food fed to the mice tastes like cookie dough,” explains the expert, who admits that “neural activity may also have been an important factor. Hoping to help people suffering from obesity, scientists have been studying the mechanisms that regulate feelings of fullness and hunger for many years. According to the popular science website The Conversation, the human brain has a “food reward” system that encourages us to consume high-calorie foods. Such a reward is capable of overriding the satiation signals that enter the brain, making it much harder for us to resist the temptation to continue feasting. Since eating delicious food gives us immense pleasure, the anticipation of such pleasurable sensations becomes the most important factor in determining our diet. At the same time, scientists have shown that people find it particularly difficult to resist fast foods that are high in fat and sugar, such as chocolate, ice cream, chips, or cookies.
The mechanisms of food consumption have been formed in humans since primitive times. We explain quickly, simply, and clearly what happened, why it matters, and what will happen next. Episodes End of story: Podcast Advertising. Some people have brain centers that stimulate food consumption much more actively than others. For example, as The Conversation writes, scientists have shown that for those who love chocolate, the sight and smell of sweets elicit a more active response in the brain regions responsible for “food reward. Such mechanisms lead us to form strong associations between a place and a type of food: when we go to the beach, we buy fish and seafood; when we go to the movies, we eat popcorn. The “food reward” system helps us find the food we need and encourages consumption. Its emergence is associated with the distant past of humanity, when people were hunter-gatherers. To survive, they needed to find high-calorie food quickly – and eat as much as possible. In those conditions, overeating helped people survive times when there was no food at all. In modern society, however, the evolutionary drive for fatty and sugary foods leads to the risk of obesity. In addition, it is much cheaper to produce non-nutritious but nutritious products than it is to produce dietary products.