A new programme aimed at getting the nation back in shape through a better diet and more exercise is to be rolled out across the country.
The latest figures, in a report from the European Commission, show that the obesity rate in the UK has increased over the past decade, making it the second highest in the EU.
But NHS England chief executive Simon Stevens said "if we get our act together" the country can prove obesity is not inevitable.
As part of the programme, thousands of people at risk of diabetes will be offered support to improve their health.
From next month NHS England will work with Diabetes UK, Public Health England and local politicians to develop the first national programme to prevent the growth of the disease.
More than three million people in the UK have diabetes.
Mr Stevens said: "The ghost of Christmases past reminds us that 20 years ago we didn't have these problems as a nation. The ghost of Christmases future tells us that if we get our act together - as the NHS, as parents, as schools, the food industry - we can get back in shape."
Criticising as "daft" recent judgments by the European Court of Justice, one of which said people who are obese could also be considered disabled, Mr Stevens said obesity was not something to be accepted.
He said: "Rather than recent daft judgments by the European court practically pretending that obesity is inevitable, in England in 2015 we're going to start proving that it isn't.
"That's why the NHS is going to be funding a new national programme, proven to work, that will offer tens of thousands of people at risk of diabetes proper support to get healthier, eat better and exercise more."
The NHS England leader said those at risk of diabetes can cut their chances of getting the disease by 60% if they lose between five and 7% of their body weight.
"If this was a pill we'd be popping it - instead its a well designed programme of exercise, eating well and making smart health choices, and we're going to start making it available free on the NHS."
Obesity costs the British taxpayer more than police, prisons and fire service combined, independent research earlier this year found.