"Cut down on the beer? No sweat"

The call for a slimmer Ken Clarke has come from a cabal of so-called "friends" who think the one-time front bench Tory MP needs to lose his beer belly if he is to have a hope of winning the contest and taking on the leaner, meaner Tony Blair at the next election.

"We have told him for his own good that he ought to lose weight," one anonymous friend told a Sunday newspaper.

But bearing in mind his celebrated love of real ale and curries, what is Mr Clarke to do? After all, time is not on his side.

If he does make it through the initial knockout rounds of the leadership contest, he would go forward to a vote of the Tory party membership some time in late August or early September.

Before the tummy trouble set in

That leaves him about two months to discard his calorific vices and shed a couple of inches from that generous girth.

All of which calls for a radical change of eating and drinking habits, according to dietician Carol Matta.

The average man of Ken Clarke's age - 60 - needs about 2,400 calories a day to get by healthily. The average pint of bitter has 184 calories.

While no one is suggesting Mr Clarke makes up his daily allowance on beer alone - at almost 14 pints a day he can leave that to William Hague - it's worth remembering even the finest pint of real ale scores low on essential nutrients.

Exercise counts

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"When it comes to fibre, protein, vitamins and minerals, these are only found in beer in the most negligible quantities," says Ms Matta.

Lager, cider and wine are all comparable on the high-in-calorie, low-in-goodness stakes.

Ms Matta suggests cutting down on consumption when he goes out for a drink, or just not going out as much.

Another tip is to dilute the beer with low-calorie lemonade. Somehow it's hard to imagine Mr Clarke, a fully paid-up member of the Parliamentary Beer Club, settling for a shandy over of a pint of hand-pulled Ruddles or Old Speckled Hen.

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Noted real ale enthusiast and journalist Roger Protz thinks Mr Clarke should carry on supping. Beer, he says has been mistakenly maligned.

"Even the strongest beer is 93% water. I heard from a couple of doctors recently that beer itself is not the problem, so much as the fatty snacks associated with a night down the pub," says Mr Protz.

"You see it in the pub all the time, people are enjoying a pint and just chomp away on a packet of crisps [153 calories per 28g pack] or a plate of chips [450 calories for an average 165g serving].

"It's detrimental to the image of beer drinkers," says Mr Protz, who admits to having a "bit" of a belly himself.

Celebrated slimmer and former Chancellor Lord Lawson might have some tips

Whatever the cause - beer or bar snacks - Mr Clarke will have to combine abstinence with a well-balanced diet rich in fruit, fresh vegetables and carbohydrate-heavy foods such as bread, potatoes, rice and pasta, and exercise, says Ms Matta.

And despite the late-August deadline, he is not advised to opt for a quick fix solution.

"Sensible weight loss means losing one to two pounds a week. With crash diets you end up feeling hungry and soon you're back to where you started."

For Ken Clarke, who has said he would rather return to the back benches than serve under any other leader, being back where he started is a risk he seems willing to take.