Why do you have the will to ‘taste’ even at the end of having eaten?

Ayou just had dinner and you're happy. He sits on the couch to watch a series and, even without hunger, ends up snacking one – or two – snacks. 

A new study published in Appetite reveals why this happens. According to Real Simple, research suggests that the food-related stimuli work as habits, being automatic responses learned, constructed throughout life, in which food is associated with pleasure. 

“ These usual brain responses can operate independently of our conscious decisions”, reveals Thomas Sambrook, professor of psychology. “Although you may think you are eating because you are hungry, the brain may simply be following a known path.”. 

What are food signs?

Food stimuli are signs that direct our focus to food, activating our instincts for the search for food, highlights Timothy Frie, a nutritional neuroscientist. 

These can be sensory (such as vision and smell), environmental (day time and location), social (people with whom you are) or internal (lack of energy, stress, emotions, boredom and memory). 

“The brain learns these associations through associative conditioning,” notes Frie. “Repeated associations, such as eating popcorn during a movie, link the stimulus to an expected result. When the stimulus appears, the brain generates a prediction: food, and the reward associated with its consumption, is on its way. This prediction activates reward and motivation circuits, particularly dopaminergic pathways, and prepares the body to eat.”.

It is at these times that salivation increases and concentration begins to focus on food. This happens as an anticipation to the meal and is driven by both the expectation learned and the energy needs. 

The study also found that yielding to eating stimuli is not about self-control. Even disciplined people can be harmed by automatic neural responses. 

“ Neurodivergent people, who have suffered trauma, have chronic diseases and live deep chronic stress, will probably present some degree of deregulation of appetite and cognitive dysfunction, which may make it difficult to meet their nutritional needs and the interpretation of the signs of hunger and satiety ", said Frie.

Signs of physical versus emotional hunger

Liza Baler, health coach, explains the differences between physical and emotional hunger. 

Physical hunger:

– It gradually emerges in response to the needs of the body;
– It can be satiated. When you are satisfied, you no longer eat;
– It can be postponed. Even though he realizes he's hungry, he can wait half an hour;
– It can be satisfied with a wide variety of foods;
– It doesn't coincide or end with negative feelings about what or how much you ate.

Emotional hunger: 

– It suddenly appears as a response to the needs of the mind/heart;
– Feeling of insatiability. Never feels full enough; 
– I wish for instant gratification. You need to eat soon; 
– Desire for specific foods or combinations of foods; 
– It causes feelings of guilt, shame or impotence during or after a meal. 

“ Eating for emotional reasons is a sign that we dissociate ourselves from the signs of physical hunger in our body,” Baker says. Instead, we eat because we are feeling an emotion — usually stress — or because it is a certain time of day, we are with certain people or in a certain place, etc.”

Why does the brain respond to eating stimuli even when we're full?

According to Frie, there are two types of hunger: homeostatic and hedonic. “Homeostatic hunger occurs when our brain perceives a deficiency of energy or nutrients, and hedonic hunger occurs when we seek a reward or stimulation in the absence of physiological need for energy or nutrients.”. 

Driven by the circuits of pleasure and habit of the brain, hedonic hunger is a psychological, not physical desire. That is, it's the feeling of wanting to eat, even when the stomach is full and the body has energy. 

“ Hedonic hunger is mediated by brain regions such as amygdala, hippocampus and striatum, which encode the memory and value of the reward ", stresses. “These systems can override the signs of hypothalamus satiety”. 

Thus, the brain learns to predict a reward whenever it finds a familiar food trigger, which causes one to seek a snack. Foods rich in fat or sugar accelerate this process, flooding the brain with dopamine, which makes the connection learned even more powerful.