"saturated fat significantly worsen insulin-resistance, while monounsaturated and polyunsaturated fatty acids improve it through modifications in the composition of cell membranes which reflect at least in part dietary fat composition"[0]
"Fat in the bloodstream can build up inside the muscle cell and create toxic fatty breakdown products and free radicals that can block the insulin signaling process. When that happens, no matter how much insulin we have in our blood, it won’t be able to open the glucose gates." [1]
So it's interesting to me, then, that the crux of what Tim Ferris says is accurate in a different light- the fat seems to clog the insulin response from the cells (including fat cells) which would lead me to believe that's beneficial in some way to stop the addition of sugar to fat cells. IANADr tho.
[0] http://www.ncbi.nlm.nih.gov/pubmed/15297079
[1] http://www.forksoverknives.com/fat-insulin-resistance-blood-...
Edit: Just found this one too... very interesting
"In conclusion, the present study shows that a high-fat KD causes hepatic insulin resistance in mice, which can be attributed to an increase in hepatic DAG content, leading to PKCε activation and subsequent impaired insulin signaling. Moreover, this study found that a KD increases energy expenditure, which results in weight loss. Given the widespread use of KD in the treatment of obesity and the role of NAFLD and hepatic insulin resistance in promoting type 2 diabetes, these results may have important clinical implications, as obese patients on such diets could lose weight but develop NAFLD and hepatic insulin resistance."