There’s a huge disconnect between what scientists know about diet and what ordinary people are being taught about diet. Most people seem to think that people get diabetes from eating too much sugar or starch. However, the scientists who wrote this article seem to think that it’s common knowledge, at least among scientists, that people get type 2 diabetes from eating too much fat.
Note: To learn how fatty diets cause blood sugar problems, read my book Thin Diabetes, Fat Diabetes: Prevent Type 1, Cure Type 2.
Animal-based foods are probably worse than plant-based foods in promoting insulin resistance, not just because of the kinds of fat in them but also because of the overload of branched-chain amino acids.
http://www.sciencedaily.com/releases/2009/04/090407130905.htm
Nearly all studies of nutrition have some sort of methodological flaw or limitation. However, these problems are often addressed by other studies. If you want to understand nutrition, you have to look at the scientific evidence as a whole. For a good explanation of what happened when people refused to look at all of the evidence about dietary fat, see the book The Cholesterol Wars: The Skeptics Vs. The Preponderance of the Evidence, by Daniel Steinberg. http://books.google.com/books?id=MQp2AB9QnoMC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false
I took some economics courses in school and I’ve been involved in medical publishing for more than 20 years, so I’m not naive. Nevertheless, I think it’s silly to imagine that “who paid for the study” is “the most important piece of data.” Financing makes a huge difference in what research gets done, how it gets done, and whether the results get published, but there’s no reason to suspect that all those scientists whose work keeps showing that fatty diets are bad for human health are involved in a vast conspiracy to commit scientific misconduct, even if you don’t like their results!