If you want to know if you are, as Rubin calls it, in a state of hyper-insulinemia or hypo-metabolic, you can measure your blood glucose throughout the day, before and after eating. You should see strong highs and deep lows: an example might be, a high of 150 and a low of 100. Or a high of 120 and a low of 80. It's the relative variance that matters more than the absolute numbers.
With a little simple self-experimentation you'll prove to yourself that fructose and extremely low fat improve this variance, as does coffee with food, aspirin and niacinamide/thiamine.
In contrast, starch and more than a very little fat reduce the variance in the glucose readings. [With the exception of MCTs that are converted to short short chain fatty acids.]
Biophysically, because most people are reliant on lipolysis for energy, a diet of starch or more than a little fat only perpetuates the lipolysis, interfering with insulin uptake inside the cells, which in turn creates high insulin gradients outside the cells.