Every bite is a memory and the most powerful memories are the first ones.

Wherever you start, the first step to eating better is to recognise that our tastes and habits are not fixed but changeable.

When the flavour of white bread and processed meat are linked in your memory with the warmth and authority of a parent and the camaraderie of siblings, it can feel like a betrayal to stop eating them.

If we want to relearn how to eat, we need to become children again. Bad food habits can only change by making ‘healthy food’ something pleasure-giving. If we experience healthy food as a coercion - something requiring willpower - it can never taste delicious.

It’s seldom easy to change habits, particularly those so bound up with memories of family and childhood, but, whatever our age, it looks as if eating well is surprisingly teachable skill.

Parents and children resemble each other no more in the foods they like than couples do, suggesting that nurture - who you eat with - is more powerful than nature in determining our food habits. Whatever our innate dispositions, our experience with food can override them.

Appetite is a profoundly social impulse.

Anything eaten just before a bout of stomach bug may be hated for life.

Likes and dislikes cannot be reduced to molecules and genes. It means that our food habits are not final and fixed but adaptable and open, if only we will give ourselves half a chance. We did not come into the world disliking bitter greens; we were taught to dislike them by our environment. Taste may be identity but it is not destiny. The hope is that while we are stuck with our genes, the environment is something that can change.