> I don't know that you can attribute bad eating habits to the recommendations of public health organisations.

Americans have actually followed the recommendations of the USDA for years. They replaced saturated fat with “heart healthy” seed oils, and they diligently consumed low fat diets.

Keep in mind that official recommendations will affect what foods are available for sale too.

> My understanding is that processed foods and sugary drinks are consumed in great numbers, but that is certainly not in accordance with the recommendation of any public health organisations that I know of.

In the United States nutrition labels have a maximum daily amount of most nutrients, except sugar. The official line has been that saturated fat causes heart disease, and that replacing fat in packaged goods with sugar was ok. This is why we have candy in the United States proudly labeling itself as a “fat free food”, and we used to have marketing campaigns touting the weight loss benefit of sugar.

This is finally starting to turn around, but the public health agencies have been laggards when it comes to the realization of how bad sugar is, not at the forefront.

And that’s not even getting into the whole bailiwick about how they process foods, which has changed in accordance with public health recommendations. They used to at least use natural fats in the few processed foods we used to eat, such as lard, but all of those were changed years ago to seed oils that were nominally less bad.

> Also, as far as I know, public vaccination programmes have greatly reduced, and almost eliminated many diseases like measles, tetanus and typhoid, not just in the US but the world over, although of course measles is making a comeback.

As I clearly stated, all public health programs should be judged by their outcomes, and the results of public vaccination have been an unqualified success.

But just because the official recommendations on vaccinations have worked, it doesn’t follow that the official recommendations on diet will too.

> Are you perhaps drawing a conclusion about public health bodies in western countries in general, from an experience with health services in the US?

Yes, that’s a fair criticism.

> I live in the UK and I wouldn't say that the national health service (the NHS) has collapsed.

That’s not what I said. I said that our health has collapsed, i.e. we’re fat and sick.