Eating less means you live longer, but where's the fun?

If you eat less you will live longer, according to the latest scientific research. But would you really enjoy those extra few years if you had to avoid all gastronomic excesses?

An unfortunate team of mice at the University of Wisconsin, Madison, struggled through a reduced calorie diet which trimmed 24 per cent off their normal daily food intake. The trade-off was a dramatic slowing of the ageing process.

The reduced-calorie mice seemed to be "biologically younger" over time than animals given a normal diet, according to Prof Tomas Prolla and Prof Richard Weindruch. So not only did the mice live longer, it must have felt that way, too.

It has been known for some time that laboratory animals living on reduced rations seem to live longer than their better-fed peers, but scientists did not understand why this might be so.

In an elegant piece of research, the Madison team used powerful new "gene chip" technology to chart the action of 6,347 individual genes in two sets of mice, one given a standard diet and the other a reduced diet.

The team monitored gene action over the life of the mice and found that only 2 per cent of the genes studied changed their activity markedly with age. These were the genes which governed key biological tasks including metabolism, energy production and DNA repair.

When we eat food, toxic by-products are produced. Our bodies are very efficient at cleaning them up and then repairing any damage they might have caused, particularly to sensitive DNA.

A declining ability to carry out the DNA repairs that keep cells healthy is a key feature of ageing, whether in mice or humans. Anything that can forestall this decline should, in turn, extend life and delay the onset of life-threatening illnesses. This is, in fact, what happened with the hungry mice.

The findings support the idea that reducing calories slows the metabolism. This reduces the production of toxic by-products but also causes a shift in resources to upgrade cell repair.

So would it work on humans? Dr Brian Merry, a leading Liverpool University expert on the ageing process, believes it might.

"All these proteins and processes have existed throughout evolutionary history," he said. "If calorie reduction is affecting these basic molecular processes, there is no reason why it shouldn't work in humans."

At what price, however? Would life be worth living without the occasional cream-bun binge? Life would be long indeed without that extra helping of new potatoes smothered in butter. And what of Mississippi Mud Pie or even apple tart and cream? Take those out of the equation and decide whether you need to get that presidential cheque in the post on your 100th birthday.

Additional reporting by PA