Just one in 13 teenage girls are getting their recommended five portions of fruit and vegetables a day, official Government data shows.
But boys in the 11 to 18 age group did little better, with just one in eight eating the right amount, the National Diet and Nutrition Survey of 2,000 adults found.
Adults ate more on average, with a third getting their five-a-day.
The average consumption of fruit and vegetables for girls aged 11 to 18 was 2.7 portions with just 7 getting five-a-day.
Chief Medical Officer Professor Dame Sally Davies said:
"It is really important that teenagers eat a balanced diet – including eating five portions of fruit and veg a day. Eating well and being active can help prevent serious illnesses such as cancer and heart disease later in life.
"For tips on what makes up your 5-a-day and how to be more active, visit the Change4Life website."
The survey drew on findings from interviews, diaries and blood and urine samples taken during 2008 and 2010. It marks the start of an ongoing programme of research which will inform Government policy.
As such, direct comparisons with previous studies are difficult - although similar research was carried out in the 1990s which showed on most counts eating habits were improving slightly.
But Dr Alison Lennox, one of the nutrition experts involved in the research, said there was still a "long way to go".
"We are seeing small but encouraging signs of healthy eating in the UK – more fruit and vegetables and less soft drinks and confectionery, especially by children – but we have a long way to go. Our saturated fat intakes are still too high."
However, she did highlight the progress being made with younger children who seemed to be eating fewer sweets, fizzy drinks and chocolate.
Health minister Paul Burstow said the Government was planning to run a new campaign in the summer to encourage families to eat more fruit and vegetables.
He added: "We want people to know that they can change what they do and make a difference to their health. Over the last ten years, we have not seen the improvements we should have. That is why the Government is using new ways to achieve better results including bringing together key partners in charity and businesses to help people to make healthier choices. This will help us to move further and faster on issues like obesity."
Mum-of-three teens Jacquie Jones, 46, from Stoke Newington, North London, said: 'It can be hard checking my teenagers are eating fruit and veg. I make sure the fruit bowl is always well stocked, try and give them vegetables at every meal and feed my daughter's current obsession with blueberries. But I know away from home, they will always go for a burger or a doughnut over a healthy banana.'
Do you worry your teens don't eat their five a day? Any cunning ploys?