The state of the nation's health should not be confused with the state of its national health service. Labour ministers will win applause from future social historians for the advances they achieved in the NHS, but condemnation for the degree to which they delayed government action to stop the nation's health degenerating. Once again the impressive Commons select committee on health has sounded a wake-up call with a devastating report on obesity: up fivefold in the last 25 years with 22% of the adult population already obese and 50% overweight. Unless current trends - the fastest growing obesity in Europe - are reversed, half of all British children could be obese by 2020.

The financial cost is already estimated to be £3.5bn a year and if the problems of overweight people are added, that figure could be doubled. The physical reduction in quality of life, with strong links between obesity and diabetes, heart disease and cancer is even more daunting. Obesity will soon supersede tobacco as the greatest cause of premature death in this country. It is already threatening the positive trend which the decline in smoking has had in combating heart disease. For the first time in generations, Britain now faces a decline in life expectancy with obesity sufferers losing nine years of life. Yesterday's report could not have been better timed, with a government consultation period prior to the publication of a public health white paper now drawing to a close.

Seven separate government departments are severely criticised for not having a more joined-up approach to public health. Among the villains are education (allowing food manufacturers to link the provision of free school sports equipment to the consumption of crisps and chocolate) and transport (which allowed pedestrians and cyclists to be swept aside in the reshaping of cities to meet the demands of the car). The MPs rightly condemn Tessa Jowell, in her role as a former public health minister, for echoing the food industry's mantra that there is no such thing as unhealthy food, only unhealthy diets. The big disappointment is the readiness of the MPs - pushed by Tory members of the committee - to give the food industry three more years to clean up its act on junk food. Just how unrealistic this is was demonstrated by the British Soft Drinks Association's immediate rejection of the committee's suggested "traffic light" warning system on unhealthy food - too much sugar, salt or fat. The simple truth, which parliament must face, is that the food industry will not reform unless it is forced to.