My apologies to anyone who received this in their RSS feed on Thursday as a teaser. I have now revised and extended it to include several studies showing that diet-induced obesity can be achieved in rats and mice without using any sugar at all, and have included a clearer conclusion.
Ancel Keys is best known in the assorted real food communities, or at least the assortment of real food communities friendly to dietary fat, for his infamous cherry picking.
Keys had presented data from six countries, purporting to show a clear linear relationship between the amount of fat consumed in a country and its incidence of heart disease. This graph is shown on the left below. The one problem was that data was available for 22 countries at the time, and including that data demolished the relationship. The "true" graph is shown below on the right.
December 22, 2011 Update: It would be more appropriate to say that including the data "greatly diminished" the relationship than that it "demolished" the relationship because the positive relationship still exists. See this excellent analysis by Denise Minger.
If we are going to criticize Keys for cherry picking, it behooves us to root out cherry picking from our own communities as well. This requires constant self-criticism, because bias is human nature, and anyone who isn't engaged in a devoted battle to overcome their own bias will be its prisoner. I myself cannot claim to always be victorious in this battle, but I do try.
I consider Dr. Robert Lustig an ally in the fight for real food. He makes as his primary enemies junk foods rich in refined sugar and high fructose corn syrup, and I agree these should be targeted as likely the most important causes of chronic disease. Dr. Lustig and many in the blogosphere, however, are circulating the claim that high-fat diets only induce obesity in laboratory animals if they are also high in sucrose. This simply isn't true.