We all know that morning. The night was short, the sleep poor, and somewhere around noon the hand reaches on its own for something sweet or fatty - chocolate, a croissant, crisps. Then comes the feeling of guilt: „I don't have enough willpower”. Science says the guilt is misaddressed. The problem is not in your character, but in your hormones and in a brain that has not slept enough.

Psychologist Esther Boada, a specialist in eating disorders, explains the mechanism simply. When the body does not sleep enough, it reads this as an imbalance and reacts with a hormonal shift: leptin, the hormone that signals fullness, falls, while ghrelin, the hunger hormone, rises. The result is a body that demands more food, and precisely the most calorific kind - rich in sugar and fat. Boada refers to the research of Karine Spiegel, which showed exactly this effect years ago.

But the story does not end with hormones. A sleep-deprived brain loses part of its ability to regulate emotions and control impulses. Concentration, memory and self-control decline, while irritability and intolerance to stress rise. At the same time, the reward centres in the brain light up more strongly when they catch sight of high-calorie food, while the zones for self-control work more weakly. In other words - the craving becomes louder, and the brake weaker.

This is where the work of neuroscientist Matthew Walker comes in, who calls sleep „one of the great regulators” of the balance between biological needs and conscious decisions. When that regulator is missing, decisions about food are no longer made with reason, but with a tired brain seeking quick energy. And that is not a weakness - it is biology.

What to do? Boada suggests something that sounds almost unromantic: instead of diets and self-criticism, let rest be the priority. Don't skip meals, prepare healthy and filling options in advance, and stop blaming yourself for something that is physiology, not a moral weakness. Sometimes the best thing we can do for our diet does not happen in the kitchen or at the gym - but in bed, with a few more hours of sleep.