Ministers a drawing up long term action plans to tackle obesity, amidst reports that a government study will conclude that half the population could be obese within 25 years.

The study showed there had to be "further and faster" efforts beyond existing anti-obesity measures to encourage exercise and healthy eating, Mr Johnson said.

Prime Minister Gordon Brown is backing long-term action plan to fight obesity.  The government is due to ask the Food Standards Agency to investigate the use of unhealthy "trans-fats", which have been linked to coronary heart disease.  Trans fats are industrially created by partially hydrogenating plant oils, and unlike other dietary fats are neither required nor beneficial healthwise.

But Mr Johnson said individuals also had to take responsibility for their own health as part of a "cultural and societal shift".

He said: "There is no single solution to tackle obesity and it cannot be tackled by government action alone.

"We will only succeed if the problem is recognised, owned and addressed at every level and every part of society."

Excess body fat is blamed for 58 percent of type 2 diabetes, 21 percent of heart disease and between 8 percent and 42 percent of certain cancers, such as endometrial, breast and colon.

Dr Colin Waine - who chairs the National Obesity Forum - said recently, "We are now in a situation where levels of childhood obesity will lead to the first cut in life expectancy for 200 years. These children are likely to die before their parents."