An increase in the number of builders' bums on show is all down to low calorie bread brand Nimble - according to its recent TV ad campaign, anyway. The brand targeted a male audience for the first time and showed builders tucking into sandwiches at lunchtime, unaware that they were made with Nimble bread. The net effect was that their jeans no longer fitted properly and kept falling down at work. According to the company, the campaign showed how Nimble had moved with the times.