"Thirty years of research show that exercising and eating lower fat, fiber-rich foods can at least delay diabetes. "If you delay it long enough," adds Dr. Knowler, "It's almost as good as preventing it...
[NIH doctors] also discovered that high levels of insulin in the blood, or hyper-insulinemia, is another strong risk factor.
Studying this clue, researchers working with patients found that high levels of insulin were linked to insulin resistance. Normally, the pancreas releases insulin to regulate the amount of sugar or glucose in the blood. People who have non-insulin-dependent or Type II diabetes (hereafter referred to simply as "diabetes") produce insulin, but their bodies don't respond to it effectively. NIH researchers have made it clear that people with insulin resistance are those most likely to get diabetes...
The second strategy is to encourage those who are at high risk to change behaviors that can lead to diabetes, such as eating a high fat diet, being physically inactive, and being overweight.
The NIH has begun a major nation-wide program to prevent diabetes in people who increase exercise and eat lower fat foods." [emphasis mine]
Now let me explain something to you that even a five year old should be able to understand. We have three basic nutrients, fat, carbohydrates and protein. Carbohydrates break down in the blood into sugar. This causes you to secrete insulin, sometimes it makes people insulin resistant, some think quite possibly because of exposure to sugar and/or refined carbohydrates.
Once you are insulin resistant, simply cutting out the sugar and simple carbohydrates doesn't stop you from being insulin resistant. If you continue to eat carbohydrates, depending on genetics, you may become type 2 diabetic. If you don't eat carbohydrates, and restrict them severely, you will not. It's not possible (to my knowledge) to become diabetic if you are not eating carbs, because you don't have an increase in blood sugar if you're not consuming carbohydrates and therefore very little insulin is secreted. Some people can eat more carbs than others and be okay. Some have to cut out all carbohydrates, as in the case Taubes mentions in his book about the du Pont executive who couldn't even eat an apple. Some have said their insulin resistance improves after months of being on a low carb diet, and they can then have some carbs without having problems.
So you tell me why in the hell they are advocating that people who are already insulin resistant eat more carbohydrates? Because that's what they're doing. By lowering fat you raise carbohydrate consumption. Protein intake cannot increase very much, you can't tolerate too much of it (unless you're body building and breaking down muscle).
Why do they blame fat? I think it's because of the mistaken notion that since the Pima were agriculturalists that meant they didn't eat meat and that they only ate carbs. There isn't a single documented case of a native society being completely vegetarian, that I know of anyway. They usually tend to eat whatever they can get their hands on.
"A dietary change common to all these cases [of Native American cultures] has been the increased consumption of sugar and refined carbohydrates ... Since the key diagnostic feature of diabetes is high blood sugar, often accompanied by sugar in the urine, diabetes is frequently spoken of as "sugar diabetes" and "I've got sugar" or "I've got high sugar"... All carbohydrates cause a rise in blood glucose, and the glycemic index, a meaure of the impact of food or a meal on the rise in blood glucose, has a significant but transitory effect on both insulin production and glucose homeostasis." --from the Encyclopedia of medical anthropology by Carol R Ember, p 342
Since the Pima didn't grow sugar or refine grain to within an inch of it's life, I'm going to go with door number 1. And that is, the Pima are overweight or obese and diabetic because they consume carbohydrates typically found in the western diet. They may have consumed carbohydrates before contact with Europeans, but they were not the same kind of carbohydrates. Also, because they live in a rather inhospitable place, they may have not gotten enough calories, and this functions in much the same way as carbohydrate restriction if Ancel Key's studies on starvation are worth anything.
It's sad that all of the Native Americans' ancestors were screwed over by the Europeans. But what's even sadder, is that they are continuing to be screwed over even today, just like every other overweight or obese person in this country who has been told that they're fat because they eat too much. They will continue to get type 2 diabetes, will continue to have legs amputated and will continue to die prematurely as long as the lie that fat is the problem is perpetuated.