While the government is worried by childhood obesity, thousands of girls want to lose more than a stone, according a survey by Bliss magazine.

Studies commissioned by the government suggest one in three 11- to 15-year-old girls is overweight.

Bliss surveyed 2,000 girls aged 10 to 19, and found nine in 10 were unhappy with their bodies. Two-thirds of the sample, average age 14, thought they needed to lose weight, and 64% under 13 said they had been on a diet. Eight in 10 wanted to lose more than half a stone, and 46% a full stone.

More than a quarter of 14-year-olds said they had considered plastic surgery. Two in 10 said they had an eating disorder.

Of those unhappy with their bodies, nine in 10 thought their mother had "an insecure body image".

Britney Spears was thought to have the best body among celebrities, followed by Beyoncé and Christine Aguilera.

Helen Johnston, the editor of Bliss, said: "It's tragic even girls of normal weight want to be skinny. They are driving themselves mad trying to achieve unrealistic bodies that even supermodels won't lay claim to."