Professor David Hunter, a leading public health expert, warned that the NHS could become “unaffordable” within decades because of the cost of treating conditions linked to obesity, such as heart disease and diabetes.

Ministers should force manufacturers to place warnings similar to those on cigarette packets on foods which contain high amounts of fat, sugar or salt, he said.

The call comes just a week after it was revealed that the NHS now spends £750 million a year on drugs to treat conditions related to unhealthy lifestyles.

More than one in four adults in Britain are currently obese.

Prof Hunter, from Durham University, said that while some responsibility lay with the individual, obesity was becoming such a serious public health problem that “strong” Government action was necessary.

Warning labels could lead to the eventual withdrawal of extremely unhealthy foods from the supermarket shelf, he added.

“The problem of obesity needs to be tackled by strong action from the Government,” he said.

“There are many products which contain such high levels of fat and other ingredients that they are contributing to health problems.

“Rather than banning foods it would be a system of food labelling and working with the food industry to phase these products out.

“(Removing unhealthy foods from sale) would be in the interests of industry as well,” he added, “after all consumers can’t keep buying their products if they are unwell or even dead.”

An official body such as the Food Standards Agency should decide which foods should be forced to carry the warning, he said.

Prof Hunter, who has written a book analysing the challenges facing the NHS, called The Health Debate, also called for more emphasis on prevention of illness in the health service.

If ministers do nothing the increasing cost of lifestyle-related diseases “will prove financially unsustainable making the NHS unaffordable”, he warned.

Experts believe that if trends continue half of British adults will be obese by 2050.