Obesity has become “the new smoking” and is set to fuel double the number of weight-related cancers within two decades, the head of the NHS today warns.

Simon Stevens raised fears that the UK is apeing the United States, as medics warned that today’s deadly lifestyles could set back decades of medical advances.

The NHS forecasts show that by 2035, the health service is set to be treating more than 40,000 cases of cancer linked to excess weight - a rise from around 22,800 in 2015.

By 2030, there will be around 36,800 such cases annually - around 100 a day - the statistics suggest.

And by 2043, obesity is set to overtake smoking as being the leading preventable cause of cancer in women.

Mr Stevens warned that obesity has become “the new smoking,” as 40,000 medics today met for the world’s largest cancer conference.

The chief executive of the NHS, said: “While cancer survival is at a record high, many people don’t yet realise that obesity causes cancer. On current trends by 2030 we could see 100 new patients every day being diagnosed with obesity-related cancer.

“So obesity is the new smoking, and if we continue to pile on the pounds, we’re heading for thousands more avoidable cancer deaths every year.”