According to Peter Whoriskey’s Washington Post report this morning, the latest conventional wisdom to reverse in the nutrition world is on whole versus low-fat milk:

U.S. dietary guidelines have long recommended that people steer clear of whole milk, and for decades, Americans have obeyed. Whole milk sales shrunk. It was banned from school lunch programs. Purchases of low-fat dairy climbed.

…[But] research published in recent years indicates that the opposite might be true: millions might have been better off had they stuck with whole milk.

Scientists who tallied diet and health records for several thousand patients over ten years found, for example, that contrary to the government advice, people who consumed more milk fat had lower incidence of heart disease.

Readers of this space will be familiar with the pattern. Previous advice from Washington about the supposed hazards of eggs and other cholesterol-laden foods, the advantages of replacing butter and other animal fats with trans fats, and the gains to be made from switching from regular to diet soda, have all had to be re-evaluated and sometimes reversed in later years. And yet some in the public health establishment — including a few who are quoted in today’s Post article— still aspire to use the power of government to coerce changes in citizens’ diet. They seem to imagine that with people like themselves in charge, next time will be different.