Yes, the insulin model is way overblown. Most diabetics are not adviced to fast anyway but rather have 3-4 meals per day. So they actually don't even have a need to put some oils in their coffee (thinking about this actually hurts bad every time I do). And for healthy folks there is absolutely no benefit in oiling or buttering their coffee aside from adding calories. Btw: Calorie control is a lot more important in terms of overall health than insulin.