I have to agree on the saturated fat causing insulin resistance part. Although slightly different being T1, if I eat too much saturated fat I always develop temporary insulin resistance. The evidence is blinding through my CGM trends, if I have a high fat meal in the evening, my BG climbs and climbs during the night. If I don't, it remains fairly steady (minus my DP and waking rise issues). The same phenomenon is apparent if I eat a high fat lunch, although I'm very active so the impact isn't as severe.
For those who deny claims that excessive fat causes insulin resistance and follow a carb deficient diet; I'd like to ask them how they can be so sure? If their carb intake in extremely low, how is the element of insulin resistance supposed to be gauged? Fasting BG is only part of the story, and along with HbA1c is not a definitive marker - as the absence of carbs absolutely sways the results. Unless OGTT results demonstrate better insulin sensitivity, or special tests show improvement in the body's ability to store converted glucose efficiently - it's purely speculative opinion.
There is a very good documentary called Forks Over Knives, which can be streamed on Netflix for those interested. It explores the alleged link between animal fat, diabetes and insulin resistance. I can't vouch for the credibility of the Doctors/medical professionals therein - but there seems to be plenty of them singing the same song...