The way we reward children with food is based on folk memories of a food supply that has not existed in the West for decades, when white sugar was so rare it seemed to sparkle like snow.

A treat cannot possibly have the same meaning in an era where white-flour cakes are everywhere and candy canes are sold by the dozen for less than the price of a loaf of bread.

We urgently need to invent new models of generosity. We need to find a way for a small portion to feel as much like love as a large one.

The true objective is independence: for a child to reach the point where they can regulate their own intake of food and to choose the things that will do them good while giving them pleasure. Weaning them off milk is one thing. But the real task for a parent is to wean children off needing you.

Each bite that you see the other person take reinforces your liking. Or not: it is hard to sit calmly by and carry on eating if you share a table with someone who is grumbling that peas are ‘gross’ and pinging them at you with a knife.

The social pressure to eat according to your sex matters more than it seems. For one thing, it undermines our pleasure in eating, which is seldom a good idea. women often deny themselves the dish they might really want pn the menu because they feel it isn’t “appropriate”.

What is so damaging about our gendered approach to food is that it encourages both boys and girls to feed themselves in ways that go against what their bodies require. We have got things the wrong way round. It is girls more than boys who need the most haemoglobin-boosting foods. And boys more than girls are lacking in salad and vegetables. Girl food and boy food are dangerous nonsense that prevents us from seeing the real problems of feeding boys and girls.

Contrary to the impression given by the health pages of newspapers, the greatest single nutritional shortfall in our diets right now is not our failure to eat enough ‘superfoods’, whatever those might be. It is the iron deficiency of girls.

Being able to regulate the amount of food we eat according to our needs is perhaps the single most important skill when it comes to eating, and the one that we leat often master.