When I was a young hunter gatherer at an English prep school in the 1960s, there was never enough food. If you ate quickly enough you could hold up your plate for a second helping. Being of a naturally competitive disposition, and as long as it wasn’t Banana Slop, Pig’s Liver, or Chocolate Blancmange, I’d be one of the first to be ready for seconds. Indeed, I’d be at the front of any queue that promised more calories. I’d even join the afternoon biscuit queue twice. Unfortunately I’m still the same, always the first to finish, and as I wolf down whatever is put in front of me, I must resist the urge to hold up my plate and shout out for more. I even ask for seconds on an aeroplane. Don’t ask, don’t get, I find.

Perhaps food is foremost in the mind of any small boy. At my school it was more exciting and digestible than Latin grammar, but only just. I used to keep a diary and in the absence of other excitements (daily religious services don’t get a mention) I noted down the food we were given for breakfast, lunch and tea. There were patterns to discover – Spotted Dick on Tuesday, Jam Roly-Poly on Thursday, fish on Friday, Macaroni Cheese every other Monday, baked beans on fried bread almost every other day, and always Marmite. There were few things I couldn’t eat, but Banana Slop (overripe bananas sliced into cold custard) still fills me with horror.

Food is still somewhere amongst my top five pleasures, just ahead of Wagner, and I cook and eat far more than I should. I shun light food, often to the dismay of my dinner guests, and although I have once attempted a homeopathic dinner party, it’s not something I would repeat. I still take seconds (and even thirds) if they’re offered, and I love to cajole my guests into overconsumption.

Modern life is so decadent. The problem is that hunting and gathering have moved online. It’s far too easy to buy too much. My eyes are still slightly bigger than my tummy. And supermarket marketers are far too clever, too, tempting us, just as Amazon does, with ‘other products you might like’. I try not to shop when I’m hungry, but I love to hunt on the Ocado website and let them gather the basket to my doorstep too. You need never leave home, except to work a little. And nowadays, for most of us in the Western world, it takes us only a few minutes’ work to fill the shopping trolley.

No surprise, then, to read reports over the last few days that more than half of the world is obese, and that diabetes has become one of the world’s most dangerous killers.

It’s so hard to overcome one’s instincts. Our genes say eat when you can. As a child I used to enjoy the satisfaction of a full stomach, and the feeling still trumps the psychological discomfort of a large one.

What can we do about it?

Eat less. Take control. All very well, but let’s be served less, too. I’m on a skiing holiday in Austria, on half-board terms at a lovely hotel in Solden in the Otztal valley. I know that downhill skiing is the lazier form (my brother, for example, prefers the masochistic cross-country variety), but I still kid myself that a skiing holiday is a healthy one. There’s the fresh mountain air and all that swishing and swooshing on the slopes, enough even to justify a hot chocolate or two. I spend an extra half an hour in the pool at the end of the day for good measure.

But then, come dinner time, there’s this:

I’ve rearranged the setting to get it all in shot, but this is what I found at my table on Sunday evening. It was Gala Dinner day, a banquet comprising more than five dismaying courses of hearty Austrian food. All paid for in advance, so another corner of my mind tells me I have to eat it all. But I overcame my instincts, and ate just three courses. I even pushed most of the carbohydrates to the side of the plate, ignoring, with great difficulty, the prep school rule that the plate must always be scraped clean.

There needs to be a law that forbids a restaurant from serving anyone more than 1,000 calories. I’m all for the nanny state if it can make me thinner and healthier.