I posted in May about how I got scary glucose and insulin results in a blood test. This was a sign of growing insulin resistance, which would lead to Type II diabetes if allowed to progress. I suspected two factors might be to blame: (1) the high quantities of zero-calorie soft drinks I was ingesting, and (2) despite my strict diet and general fitness, a lack of aerobic exercise.
For the following 3 months, I addressed both suspected causes. I eliminated most artificial sweeteners from my diet, and I started to exercise heavily. I believed exercise would work because: (1) studies show that regular aerobic exercise mitigates the risk of Type II diabetes; (2) all pregnant women develop insulin resistance, yet 99% get better afterward, so the condition must be reversible; (3) it would be compatible with my hypothesis about the workings of the underlying mechanism.
My hypothesis is naive, but it's compatible with my experience, and it might help someone, so here it goes. When your muscles have full energy stores, they move insulin receptors away from the cell surface. By doing so, they stop extracting glucose from the blood stream, because they have nowhere to store it. When all the muscles in your body have full energy stores, glucose stays in the blood stream. The pancreas detects this, and starts pumping out more insulin to clear the glucose. Your muscles react by hiding their insulin receptors even more, so the pancreas starts to crank out even more insulin. In effect, the pancreas is saying "come on, this glucose has to be cleared from the blood stream", but every muscle in your body is saying "I'm full, someone else take it". If you don't do something about this, eventually the pancreas burns out, and then you have Type II diabetes. But if you do regular aerobic exercise, the insulin receptors in your muscles move back to the cell surface; the pancreas doesn't have to crank out as much insulin, and your glucose and insulin levels stabilize.
In May, I put my hypothesis to the test by immediately starting a heavy-duty exercise regime. The first month, I did 40 minutes of aerobic exercise nearly every day of the week, burning about 480 kCal per day. After the first month, I reduced this to 30 minutes, or about 360 kCal. As soon as I started this, all subsequent blood tests came back clear. But not only that; I also noticed a major improvement in an embarrassing symptom that's been going on for years. Suddenly, I no longer had to pee every 90 minutes.
For years, my urination problem has been getting worse. Like many people, I ignored it. Only after the blood test, I became aware that frequent urination is a sign of insulin resistance, and a herald of Type II diabetes.
What's happening is, because of the insulin resistance, your body has continuous high levels of glucose and insulin, which are toxic in high concentrations. Your kidneys have a threshold at which they will start expelling glucose into urine. When this is happening, you notice that you're often thirsty; you have to urinate often; your pee is relatively clear; and the pee is sweet. (This last one might be awkward to verify; I didn't.)
At the peak of this problem, I would have to take a bottle of water with me wherever I went. I wasn't able to sleep through the night without getting up and peeing before going back to bed. When I went to the movies, I urinated immediately before the movie, and by the time the movie ended, my bladder was hurting again and ready to burst. But after a few weeks of heavy aerobic exercise, the problem was gone completely. I was now able to go to dinner, followed by a movie, and didn't have to pee the entire time, until after I got home.
After about 3-4 months of exercise, during which my symptoms went away, there were personal events which plunged me into several months of depression. I was in emotional agony, which was worse when I didn't have something with which to occupy my mind. This made it difficult for me to exercise, because my mind would wander and think about things that were very painful. For the 3 months from September to November, my aerobic activity dropped to near zero. It took until December for me to start noticing the insulin resistance creeping back. One morning, I had to get up an hour before I intended, because my bladder was about to burst. I finally started exercising again, and the symptoms again improved quickly.
I'm now using an exercise bike for 30 minutes at a time, burning about 340 kCal every other day. This seems to be sufficient to keep the symptoms of insulin resistance at bay. I'm still avoiding artificial sweeteners, but not as religiously as in the first few months: my diet includes Greek yoghurt and protein bars. I've also started eating chocolate again, while staying within the bounds of my controlled calorie intake, high-protein diet. So far, as long as I exercise, what I'm eating doesn't seem to be hurting.
A study published in 2014 found zero-calorie sweeteners cause diabetes through changes in gut flora.