What actually causes type 2 diabetes

As discussed above: the body is a machine. It is made of parts, and it runs on fuel. The parts are protein. The fuel is carbs and fats. Type 2 diabetes is what happens when the fuel tank overflows.

About 90–95% of all diabetes is type 2. Of that, 80–90% can pretty much be explained by the “personal fat threshold” as the cause. After years of gradual overfueling, the tank finally gets too full, overflowing into the organs that help regulate blood sugar.

Everyone has a personal limit — highly individual — for how much fat the body can store safely under the skin. Genetics largely determine this capacity: some people can generate new fat cells when full and can keep expanding subcutaneous storage, avoiding insulin resistance even as they gain substantial weight (in rare cases reaching extremes like those seen on TV weighing 1,000 pounds), while others overflow after only a modest extra 10 pounds or so.

Most of us eventually max out at some point. Once that limit is passed, excess fuel spills into visceral fat around the organs. Keep filling up beyond that and fat accumulates in and around the liver and pancreas. The liver, overflowing with fat and glucose, essentially starts leaking fuel; the pancreas grows sluggish and can no longer keep up with the body’s insulin demands. Blood sugar stays elevated, hemoglobin A1c climbs, and type 2 diabetes is the result. Yes, this is a gross oversimplification, but it is essentially what is happening and has been shown in multiple studies to be the case.

My biggest pet peeve is that most patients are never told how reversible type 2 diabetes is. If you can understand the process by which you became diabetic, if we reverse your steps, we can largely revert you back to the way you were before. There are aspects that never quite return back to 100% normal, but you can get pretty close. Still, people get handed a lifetime prescription and a shrug, and I feel that we can do better.

Now just to clarify, this is NOT type 1 diabetes. Type 1 is an entirely different beast — an autoimmune failure to make insulin — and a whole other discussion.