London: When it comes to politics, bananas can cause a whole bunch of trouble. David Miliband never fully recovered his status as a serious politician after waving one in front of TV cameras during his botched leadership coup in 2008. And if he's not careful, Gordon Brown could also fall foul of the fruit. On Monday it was revealed that, in an effort to keep healthy, the Prime Minister is eating up to nine bananas a day.

But that, say experts, could cause some seriously unwanted side-effects — the least of which might include flatulence.

Brown's wife Sarah is said to be responsible for the new dietary fad, having persuaded the 58-year-old to ditch his favourite KitKats. The PM is reported to have ordered staff to leave a giant bowl of bananas in his study and eats them during meetings. He has also taken up jogging to boost his fitness.

Brown's spokesman said: "The Prime Minister has always taken the view that a balanced diet is very important. Portions of fruit and veg taken on a daily basis can only lead to good health and radiance."

Bananas are high in carbohydrates and fibre. However, experts warn that eating nine a day is "excessive" and could lead to indigestion as well as frequent trips to the toilet.

Sian Porter, from the British Dietetic Association, urged Brown to curb his intake and to replace them with other fruits for a more balanced diet.

She said: "There is a lot of fibre in bananas. A lot of volume in means a lot of volume out.

"If people decide to increase their fibre intake, we recommend that they do it gradually. Too much fibre can lead to gastrointestinal problems. We would applaud him for replacing KitKats with bananas, but we encourage people to eat a rainbow of different fruits and vegetables." Porter added that Brown needed to watch his calorie intake as a large banana contains as many as 180 calories.