You have just spent two hours preparing a varied and tasty meal for your guests, and now, despite it being dinner time, your appetite is gone. Could the food have overcome your hunger?
Hunger, a signal that plays on several levels
In reality, hunger is a complex signal. It reflects the energy needs of our body, but also the context in which we find ourselves. This signal results from a constant dialogue between the stomach, the intestine and the brain, via several hormones: ghrelin, which stimulates the appetite, and leptin or cholecystokinin, which promote satiety.
We thus distinguish two forms of hunger:
- “Physiological” hunger, linked to a real need for energy;
- “Pleasure” hunger, triggered by the sight, smell or even the simple idea of an appetizing dish.
These two hungers intersect in the brain, particularly in the cortex and the hypothalamus. Their intensity varies depending on our state of stress, our sleep, our physical activity or our emotions. This is why the same dish can seem irresistible one day… and much less tempting the next.
Satiety does not only depend on the number of calories swallowed: the texture of the food, its protein and fiber content, the pace of the meal and the atmosphere around the table also play a key role.
When the brain thinks we have already eaten
But in the kitchen things get a little trickier. “If I schematize, in fact our brain does not really differentiate true from false, explains Alexandra Murcier. So, when we cook, for him, it’s a bit like eating: he already anticipates satiety, digestion, etc.”
In other words, the simple act of cooking activates the hunger circuits as if the meal had already started. The smells, textures, and colors of food stimulate our senses, which send signals to the hypothalamus, the area of the brain that regulates hunger and satiety. This stimulation tricks the brain, which interprets these sensory signals as actual food intake. Result: the desire for the dish we are preparing gradually diminishes.
“But this illusion is not just a psychological phenomenon. It is also accompanied by a real physiological response” :
- Salivation increases;
- The digestive system starts up;
- And leptin, the satiety hormone, may even begin to be secreted.
All of these signals combined naturally reduce the feeling of hunger.
A mixture of senses, fatigue… and attention
In addition to this sensory and hormonal stimulation, the body also reacts to the kitchen environment: heat, smells, movement. The nose ends up getting used to the scents, this is what we call olfactory fatigue, and the excitement of the senses dulls.
“We also talk about “specific sensory satiety”: by smelling and tasting the same dish, our desire for this specific taste diminishes.”
And then there is concentration. Cooking means focusing your attention, moving, tasting, monitoring… This mental and physical load can, in the short term, suppress your appetite. We sometimes feel “full in advance”. As if we had already eaten just by preparing.
But rest assured: this feeling is temporary. Once the table is set and the pressure has subsided, the appetite often returns…while eating. Especially when it comes to savoring the fruits of our efforts!