EXERCISE is a fat lot of use, according to new research.

Tell me something I don't know already.

Several times in print, I've revealed exclusively that exercising for many years lost me no weight whatsoever.

This included taking up new or renewed hobbies such as five-a-side football and waddling down to the gym. Amount of weight lost: nil. Not an ounce. And, no, I didn't put on muscle to counteract weight lost. I'm incapable of adding muscle. I'd quail were Madonna to challenge me to an arm-wrestling contest. I'd stand a better chance at twerking.

My more regular exercise is good for both heart and morale, but it hasn't lost me any weight. To clarify opaquely: I didn't need to lose a huge amount of weight. I was 14 stones when I should have been maybe 11.5.

Now I'm 11.25 and it's all down to eating. That is to say, not eating. I'm not going to lecture you with my particular diet: down on potatoes and bread, up with greens, yada and a second helping of yada.

Instead, I cite a study published in the British Journal of Sports Medicine, which proclaims that excess sugar and carbohydrates - not physical inactivity - caused the recent surge in obesity.

As Dr Aseem Malhotra, a cardiologist at Frimley Park Hospital in Surrey, put it: "You cannot outrun a bad diet." Give that man a deep-fried coconut. Spot-on.

Even so, his wise words will leave many confused. It's as if we're standing at American traffic lights. The sign saying "Exercise" changes to "Don't exercise". Then it says "Eat". Then "Don't eat". We end up standing in the middle of the road bewildered, before being knocked down by life.

Every meal is a punishment or sin. We're at sixes and sevens over what we ate. "Nein!" says a German reader. "I vill never give up elevenses!"

I feel your pain, Herr Blenkinsop. But this news just in: eating less is good for you. And just to clarify: the good doctor isn't saying don't exercise. He's just saying it ain't going to make you slim.

Someone mentioned print above and, some years ago, I created a great sin therein, wherein I queried the experts' claim that we were being crushed by an epidemic of obesity. "But nobody in our street is fat," I wailed scientifically.

I admit now that I was wrong. Not that anybody in our street is fat. But the masses are. I base every quest for truth on observation and impressions, not on facts and statistics, which rarely chime with reality.

Take, therefore, a wax impression of this and stick it on your piechart: recently, in a shopping centre, I thought I'd landed on another planet. I'd fallen through a black hole and ended up in the Wobble nebula. In reality, I'd just taken a bus across Edinburgh. And, in this strange new land, everyone was fat. Everyone (nearly). It was extraordinary.

The scientists had been right all along. Until the police intervened, I inspected the wobbling bottoms in the mall and felt sorry for their owners. Clearly, they'd become addicted to sugary drinks, chocolate bars, pizzas and chips, key foodstuffs designed to be delicious by a sadistic deity.

What could I tell these people? As I mounted my Irn Bru crate to orate, all I could think of was: "It is down to you. No one else is going to make you thin. Give up the sugary stuff."

The area, I may say, was proletarian, the sort of place where I feel at home. It lacked the undignified joggers and cyclists who despoil bourgeois streets and green spaces with their garish outfits and grim faces. Running and cycling won't make you slim, merely unpopular.

The worst of it is that we're bombarded by marketing designed to make us eat rubbish. Lovely, delicious, mouth-watering rubbish. Some days I could kill for a yumyum.

Cunning capitalists even associate their sugary drinks with sport, suggesting that both are wholesome and will make you look like the gods and superheroes depicted in the adverts.

Well, loosen your waistband as I drop in this nugget: their drinks will make you look like the Incredible Bulk with a one-way ticket to Hades. Eat less, brothers and sisters. And exercise if you will. Put on your best three-piece suit and walk about rapidly in the privacy of your own home. Never did me any harm.