Apparently, in war, two things happened regarding food:
Because it was scarce and expensive and rationed it was not wasted, and whatever people could home-grow, they did:
Also, the standards of the population's health shot up, not least because the dietary needs were calculated, published, and there on the ration books for all to see, every day.
Effectively, there has been a mass mis-education brainwashing of the population, by commercial interests. If for two or three generations, people have been presented with huge portions and huge calorie-count foods and drinks, how on earth would they have any idea they are taking in far too much, let alone that the intake is nutritionally unbalanced? (There are t.v. shows displaying people's food intake, and invariably the people seem astonished they are overconsuming. They are also amazed at how cheap, easily made and enjoyable the healthy alternatives are.)
Post war, and for a long time, sugar was not freely available, nor the other useless and unhealthy mass marketed processed foods which are constantly on offer to profit from ill-health. Tobacco was promoted, mainly to men but also to women. Alcohol was not so relatively cheap and universally available, and was also considered mainly suitable for men, thus inadvertently saving women from not only the liver damage but also the calorific load.
Could the junk food and sugar and alcohol sellers be taxed, by alcohol units and by calorie content, and by sugar and salt content, and whatever else is agreed to be bad for people to consume in large amounts, and could there be an advertising ban on the main offenders, all with the intention of discouraging consumption just as tobacco, eventually, was? The I.H.T. (Ill-Health Tax) could be hypothecated, ringfenced, and circled back to the N.H.S frontline services (excluding their managers and desk-jockeys), to avoid N.H.S. resources for obesity, diabetes and alcohol related harm being an unintended government/tax-purse subsidy to the health destruction industries.