"You don't leave the table until you've eaten everything." The sentence that an entire generation growing up in the '60s, '70s and '80s heard. A teaching message, a habit, a routine. It turns out that sentence is one of the reasons why in their late thirties and forties more than half of adults have problems with eating and weight.

Nutritionist Iolanda Masa from the "Blua de Sanitas" medical centre in Spain has explained the story behind what in the professional world is called "clean-plate culture". The point: we are trained to look at the empty bottom of the plate as the sign that we're done - not what the body is saying.

"The problem appears when an external norm gets imposed over the body's natural signals," Masa says. Even more importantly, her message isn't to find someone to blame. Parents did it out of care - they wanted us to be full, for food not to be left over, for us to learn "to value" a serious meal. Back then that was healthy parenting. Today nutritional advice is completely different: don't force children to eat to the end. Respect when the body says "enough".

What happens physiologically? The signal of satiety doesn't come in a single moment - it builds. The hormones ghrelin (sending the "I'm hungry" signal) and leptin ("I'm full") talk to the brain. But it takes around 15 minutes for the signal to reach the brain. Which means: if you eat fast - often on the phone, in front of a computer or with the TV on - you'll eat much more than you need before the brain even registers that you're full.

For a Balkan context this is especially relevant. Grandma's kitchen, Sundays full of guests, "you have to eat more" - all of it is a real and beautiful cultural tradition. But when every meal lasts 15 minutes and ends with an empty plate, the body never learns when to say "enough". Masa recommends: serve smaller portions, pull the distractions away when eating, take a break in the middle of the plate - check whether you're still hungry. And by all means: drop the complex around leftovers. They can become dinner tomorrow. It's not a sin not to eat everything.