Britain faces 'losing a generation' of children to obesity-related disease, the Duchess of York has warned.
The Duchess of York is one of five guest editors of Today
Speaking as guest editor of BBC Radio 4's flagship Today programme, Sarah Ferguson called on the government to take action and tackle the problem.
She said her own problems with food helped her understand the difficulties faced by "compulsive eaters".
On air, she also voiced support for the monarchy, calling the Queen "one of the most remarkable ladies" she knew.
'Pressure on children'
The 45-year-old divorcee is spokeswoman for WeightWatchers in the US.
She said: "It's time now for everyone to wake up to the fact that this obesity situation is not a diet, it's not about whether you are fitting into a pair of blue jeans.
"The government is going to have major healthcare problems if they don't realise they could even have a lost generation because of the different diseases stemming from overweight leading to obesity."
She went on to criticise the pressure put on children to be thin.
Children today were under great pressure to "look like Britney Spears or Leonardo di Caprio," she added.
"We have got to instil much more understanding of why perhaps people are different shapes and it's OK to be as you are."
Speaking about her own difficulties with food, she said: "If you are a compulsive eater from the age of 12, then food is your only friend and you squash your emotions through food.
"It's a monster waiting to happen because you are not really being yourself...then you get to a point when you self-sabotage.
"That's why I understand how depressing and difficult having a weight problem can be. I have it now and I'll always have it."
The Duchess is one of five guests taking over the Today programme for a day each between Christmas and New Year.
Speaking about the Royal Family, she said: "Her Majesty is one of the finest and most remarkable ladies that I have ever met in my life and I'm deeply, deeply honoured to even be able to say that.
"I uphold 100% what the monarchy stands for and I think Charles is a very, very fine man."