The study, questioning over 68,000 10-to 15-year-olds last year, found nearly two-thirds (63 per cent) of girls in Year 10 (aged 14 and 15) say they would like to lose weight, along with more than half (54 per cent) of those in Year 8 (aged 12 and 13).
Over a third (37 per cent) of 10 and 11-year-old girls -- those in the final year of primary school (Year 6) -- said they would like to be slimmer.
The research, though, found boys were less concerned about how much they weigh.
The report also questioned pupils about their eating habits.
