Keto Diets and Diabetes, Michael Greger MD, 14 December 2023,

Intolerance to carbohydrates skyrocketed on a high-fat diet.

After one week on an 80 percent fat diet, you can quintuple your blood sugar spike in reaction to the same carb load compared to a week on a low-fat diet. (See below.)

Even a single day of excessive dietary fat intake can do it, as you can see in the graph below.

Clearly, if you stick to eating mostly fat, your blood sugars will stay low, but you may be actually making the underlying disease worse at the same time.