Government targets on obesity are "over optimistic", and the NHS will struggle to tackle the problem despite billions of pounds being pumped into the service, an influential report claims.
Sir Derek Wanless also questioned several of the government's key aims for health, such as moving care closer to the community, which is only supported by patchy evidence.
He said: "Between 1995 and 2005, the proportion of adult males classified as obese rose by half to 23% of the male population, while the proportion of obese women rose by 42% to around 25% of the female population.
"Childhood (two to 15 years) obesity increased by a similar extent over this period, with the proportion of obese boys and girls rising by 65% and 51% respectively; nearly one in five children are classified as obese.
"A continuing rising trend in obesity to 2010 is predicted, when some 33% of men, 28% of women, one-fifth of boys and more than one-fifth of girls will be obese."
His study for the King's Fund said evidence on obesity is "therefore of great concern", and while it is wrong to blame the NHS for the trend, achievements in combating the problem are few.
Sir Derek also criticised new contracts for nurses and consultants, adding that although they may have reduced three-month vacancy rates, "there is very little robust evidence so far to demonstrate significant benefits arising from the new pay deals".