Singer Lily Allen has said she has been diagnosed with a heart murmur that means she will have to take better care of herself.

Concerns were raised about the star's health after she dropped four dress sizes in six weeks but the Smile star rejected speculation she was dieting, saying her new figure was due to a fresh exercise routine.

Speaking to Grazia magazine, Allen said: "I really want to stress that I haven't done this because I want to become some skinny minnie – I will never be like that.

"I just like being more toned, it has made me really happy and I know I will never be super skinny because I would never be happy.

"I don't understand people who are crazy thin and deprive themselves, they must be miserable," she added.

The singer told the magazine she was now working out three times a week - a big change from her exercise-free life in the past.

Allen said she found out about her health condition, which could be harmless or an indicator of heart valve problems, three months ago during a routine check-up.

She said the news had frightened her and forced her into her new 90-minute workout sessions.

Allen told Grazia: "I had switched doctors and just went for a routine check up, which is when they discovered I had this irregular murmur.

"I have been asthmatic all my life, but this was really quite scary. When they asked me how much exercise I did, I had to be honest and say hardly any."

"I used to love nothing more than sitting in front of the telly with two packets of Ginger Nuts and two bags of milk bottle sweets – and I’d devour the lot.

"But this heart thing has made me cut back on all that kind of crap," she said.

27/11/2007 07:08:07