What are the SAD hypothesis? Perhaps we could form a complete list...
Saturated fat raises LDL which results in atherosclerotic plaque, which kills you dead, the end. Actually dietary cholesterol was first, then LDL raised by li[ids. Now I think it is that saturated fat increases LDL which increases the risk for atherosclerotic plaque but it depends somewhat on LDL receptor, HDL, and propensity to oxidize, and when it does oxidize it may or may not cause a heart attack because thrombosis is needed, via a dysfunctional eicosanoid system. Still I don't think it's air-tight but getting better. A lot of it seems to be damage to the arteries causing a need for a lot of cholesterol. There is also calcification which is a big deal.
Fiber prevents colon cancer because it shuttles poop out the poop-chute quickly and it doesn't do bad poopy things? I don't really know what to make of that one, maybe it's partially true. I think certain types of fiber prevent colon cancer because they get fermented in the get to butyrate which destroys cancer cells and reduces GI inflammation. The best fiber comes from roots, not grains, though.
Type 2 Diabetes is caused by being fat, and being fat is caused by gluttony and sloth born of poor character. In actual fact, diabetes is exacerbated by visceral fat due to the secretion of pro-inflammatory cytokines which downregulate insulin receptors, however there really is a whole lot more going on than just being fat. Inflammation from other sources and deficiencies are a huge source of insulin receptor dysfunction. They try to substantiate their fat-guy hypothesis by showing studies where people drastically cut their calories and lose some weight and their glucose numbers improve, but everyone knows that caloric restriction is a good band-aide for metabolic syndrome just because you are consuming less energy that has to be cleared from the blood. It stops poking the angry bear.
And the sloth and gluttony thing...well those things are probably the result of dysfunctional endocrine and food reward systems.
Oh and salt causes hypertension because it is used to raise blood pressure and some studies show a massive dose of salt having some impact.
I think CW is getting better and the tide will turn. The first wave tended to be a lot of half-explanations or observing the effect of the true cause and saying correlation=causation.
Super-science folks, is that all accurate? Corrections below.