Insulin resistance primarily occurs at the mitochondrial level, impairing ATP production.

“Insulin does not cause insulin resistance. This is a huge misconception. Mitochondrial dysfunction causes insulin resistance.”

“so insulin resistance some people think about insulin resistance as resulting in a fuel shortage inside the cell even though there are high levels of glucose right outside the cell and we have pretty good experimental data to suggest that's true that seems to be true um that the cells are producing less ATP than they should they have higher levels of reactive oxygen species which is a bad sign”

“those reactive oxygen species send a signal to the insulin receptor to become insulin resistant”

“if you don't have enough ATP because your mitochondria are not making enough ATP from the food you're eating you're metabolically unwell that is essentially what insulin resistance is it's a backup of energy and so what happens is when the cell doesn't make enough energy from the foods you're eating you get an energy backup and the cell signals hey we have enough energy because it's not going through the mondri electron transport chain because it's kind of broken and that's where you get insulin resistance from”

“metabolic dysfunction, insulin resistance, this primarily happens at the level of the mitochondria. If you cannot take substrate from food which is glucose or fatty acids and process them into NADH and FADH2 and move those electrons through the electron transport chain to make ATP, you are going to become insulin resistant.”