Just the thing. With glucose-lipid toxicity in a petri dish, you can just decide which free fatty acids the cells will be exposed to, and whether or not glucose will be high. In a type II diabetic or somebody who's insulin resistant/insensitive? It's a little harder. Low fat enthusiasts will point out that a high carb, low fat diet can result in increased glucose tolerance and insulin sensitivity. It can push down free fatty acids, so cells aren't exposed to the toxic mix of elevated glucose along with elevated free fatty acids. This is fine and good and may be in operation in healthy populations around the world that do or did eat lower fat, higher carbohydrate diets.

But we carry quite a lot of fat on our bodies. Even those of us who are fairly lean still carry fat stores that dwarf what we're likely to eat in a day. If we can't do that trick of lowering systemic free fatty acids by just not eating much fat, and many of us can't, at least not to the extent that would be best for that insulin sensitizing effect, then the opposite approach of instead avoiding carbs and concentrating on fat for dietary energy sources makes more sense. I think it's good that both options exist, although I think it would be wrong to insist that both options exist for everybody.

Part of the problem with high triglycerides might be just that they don't occur unless the liver is exposed to both large amounts of glucose and high levels of free fatty acids--and that when that's happening, the liver is unlikely to be the only organ in the body for which this is the case.