Also:

It’s a myth that a low carb high fat diet has to be expensive. The cheapest cuts o f meat in the UK are the healthiest – the fatty cuts and organ meats are dirt cheap because everybody thinks they are unhealthy. Eggs are very affordable and so is cheese and full fat milk. Veggies and fruit are also cheap. Because we need much less bulk on a low carb diet, we need less food overall… Not endless bags of crisps, bumper bottles of coke or biscuits and cakes….

I haven’t totted up the costs, but I bet one could live a supremely fit an healthy low carb lifestyle as cheaply – if not more so, than on the standard obesogenic poverty diet of today’s overweight Westerners.

Us middle classes can pay for unpasteurised milk and organic, outdoor reared produce of course, which is expensive, but the general benefits of cheap animal and plant products far outweigh the marginal benefits of a few extra vitamins and finer quality meat. Anyway, cooking up a good French provencal chicken using cheap meats and butter and cream will still taste dam good whatever.

First, it’s not universally true that poor people used to be skinny. Just one example: the Pima Indians, some of the poorest people in America, have had some of the highest obesity rates since they were pushed onto reservations decades ago and forced to live on white flour, sugar, tea, and other cheap foods instead of their traditional diets of game and fish. This may seem like a minor point, but if we don’t recognize that poor people have been fat for a long time (not just recently), we will not get very far in understanding causes.

Second, because of things like farm subsidies, giant agribusinesses, monoculture, and the like, many of the cheapest foods are high-carbohydrate grain products - those that provoke a large insulin response. Heck, even candy and soda are grain products now, loaded as they are with high-fructose corn syrup. And as you know, Mark, insulin is the hormone that not only causes fat storage but prevents stored fat from being used.

Third, I just ran across this on Regina Wilshire’s excellent blog, Weight of the Evidence. http://weightoftheevidence.blogspot.com/2007/12/obesity-is-it-form-of-malnutrition.html. It suggests that obesity might indeed be a variety of malnutrition. I wrote my thoughts on a comment there, but since her comments are moderated, it might take a while to show up.

Finally, government nutrition policy, which as you know is totally **ed up, probably affects poor people disproportionately. If a middle-class family wishes to buck the conventional wisdom and eat full-fat foods and red meats instead of fat-free dairy products, soy, and whole grains, they are perfectly free to do so. If a poor family wishes to do so, tough luck, they have to buy what’s allowed by WIC.