Almost half of secondary age pupils think school dinners are unhealthy, a survey suggests.
Are children eating too much junk food at school?
The research group Mori found 49% of 11 to 15 year olds feared the meals provided could increase problems such as poor nutrition and weight gain.
Meanwhile, 60% were confused over what a healthy diet was and 43% said schools lacked enough space for proper sport and exercise.
Mori interviewed 414 children across Britain for the survey.
'Not doing enough'
The health charity Developing Patient Partnerships (DPP) is asking schools to give more "sound advice" on eating habits.
Official figures for 2002 show that 8.5% of six-year-olds, and 15% of 15 year olds are obese.
DPP chairman Dr Simon Fradd said: "Action on improving nutrition in schools is clearly essential.
"But we are not doing enough to equip our young people with the knowledge and skills to be able to make healthy decisions themselves."
The Mori poll also found 27% of the 414 11 to 15 year olds interviewed thought losing weight was a health priority.
Some 36% were concerned about gaining too many pounds over the Christmas and New Year holidays.
DPP has launched a Get Sussed website, offering young people information on nutrition.
Dr Fradd said: "The possibilities for schools to have a sense of control and make healthy decisions about their lifestyles are limitless.
"The role of the education system in addressing the obesity epidemic cannot be ignored."