What was called the Mars bar standard was notionally used to judge the health of the economy, the smaller it got the more the pinch on our pockets. We now introduce the potato chip standard, a measure of our physical health, the bigger the serving – and portions are getting much larger – so too the expansion of our waistlines and general increase in our ill health.

Obesity is a new epidemic in this country, causing diabetes, heart problems and death, along with a swelling of demand on our clinical services. And it is the poorest among us who are bearing the brunt of it, because fast foods – like those extra chips – are cheaper than healthier alternatives.

So it isn't just a question of eating less, it is about both eating better and insisting that the food we consume is not stuffed with sugars, salts and questionable and cheap additives. This is where our governments, the UK and Scottish, must act, not just to regulate the food industry for the better, but to make sure that fast food vans and the like are not parked outside our schools and the food served inside is healthy and nutritious. It may lead to a bad day fo chip shops, but a better one for the rest of us.