An about-face on fat in the diet

Last updated on April 12th, 2017

The Academy of Nutrition and Dietetics, which calls itself the “world’s largest organization of food and nutrition professionals” and probably is, recently broke ranks with the anti-fat brigade, urging that the 2015 Dietary Guidelines for Americans “deemphasize saturated fat from nutrients of concern, given the lack of evidence connecting it with cardiovascular disease” (Press Release).

The wording is awkward. I think what the Academy means to say is that we should stop bad-mouthing saturated fat, at least until the evidence provides a clear reason for the bad-mouthing. The Academy wants the same position to be taken on dietary saturated fat as on dietary cholesterol. Basically, make a case against fat and cholesterol in the diet, or shut up about them.

Of course, most Americans believe the case against fat in general and saturated fat in particular has long since been made, and who can blame them? Their government has been preaching an anti-fat message for 40 years. Would it do that without conclusive evidence against fat?

Sure it would — if the available evidence had been seriously misinterpreted.

Facts are meaningless by themselves. They require interpretation. Somebody needs to fit the facts together into a meaningful pattern. Who does the fitting — the interpreting — and why, has a major impact on the meaning that gets made. We need to guard against bias in interpretation, the bias of others and of ourselves.

One type of bias is the tendency to cling to a position once taken. In short, we are reluctant to admit mistakes. The Academy acknowledges that errors have been made in interpreting the evidence against dietary fat and cholesterol, and asks others to do the same.

In its interpretation, the Academy argues that “the evidence does not lead to the conclusion that saturated fats should be replaced with polyunsaturated” in our diets. Instead, the evidence shows that “carbohydrate contributes a greater amount to the risk for cardiovascular disease than saturated fat, so the replacement of carbohydrate will necessarily result in a greater improvement in risk.” It goes onto offer a “simplified recommendation” that dietary carbohydrate be reduced and replaced with polyunsaturated fats.

While not an endorsement of saturated fat in the diet, this is a long way from the usual attack. More important, the world’s largest organization of food and nutrition professionals — 75,000  strong — has identified a different culprit — carbs. It’s calling for more fat in the diet (albeit polyunsaturated) and less carbohydrate. That’s short of telling everyone to eat LCHF, but I’ll take it.

(Update: For a forceful take on the “about-face,” see “Sorry seems to be the hardest word” by Dr. Malcolm Kendrick. I recommend his blog and books in general.)