While studies have shown that consuming saturated fat can slightly increase insulin levels, which can be a risk factor for type-2 diabetes, the studies did not reflect real-world diets, and did not reflect the fatty acid profiles consumed in normal diets.
In addition, recommendations to avoid saturated fats generally result in people consuming more trans fats, which are definitely dangerous.
Trans fats have a detrimental effect on the incidence and treatment of type-2 diabetes, while saturated fats have been shown to have no effect when appropriate comparisons are made. Trans fats interfere with insulin receptors, while saturated fats do not.
Type-2 diabetes did not exist 100 years ago, when the human diet was very rich in saturated fats; it appeared when trans fats came into the diet. As people eat more and more foods containing trans fats, it has become an epidemic.