Many weight-conscious teenage girls are not eating enough calories for their age group, a survey out today says.
Just over a third of 13 to 18-year-old girls are on diets or have dieted recently, the poll for Sainsbury's found.
And 45 per cent eat less than 1,200 calories per day, which is below the recommended intake for their age range.
Only 14 per cent of the teenage boys surveyed admitted to dieting but a quarter consumed fewer than 800 calories per day - as little as one third of their recommended daily amount.
On average, 60 per cent of the respondents wrongly estimated how many calories an adult woman and man should eat daily, which is 2,000 and 2,500 respectively.
Sainsbury's nutritionist Charlotte Parker said: "These results show that teenagers struggle to understand what constitutes a balanced diet."
According to the Food Standards Agency's "eatwell" website, young men aged 15 to 18 need about 2,755 calories a day while young women in the same age range need about 2,110 calories per day.
Boys aged 11 to 14 need about 2,220 calories a day, compared to 1,845 for girls of that age, the website says.
The Sainsbury's youth diet survey was carried out by researchers at BMRB Omnibus last month using a sample of 540 teenagers.
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