Millennials are set to be the fattest generation on record - with three quarters overweight or obese by the time they approach 40, new projections show.

Analysis by Cancer Research UK shows that the six million Britons who came of age around the millennium are far more likely to have a weight problem than the baby boomers who “never had it so good”.

The research suggests 74 per cent of millennials will be obese or overweight by the time they reach middle age - compared with a figure of 54 per cent among the post-war generation.

Experts said the figures were “horrifying,” as they warned that obesity is now the second leading cause of cancer, second only to smoking.

The figures mean millennials are the most overweight generation since records began.