I just read that one's number of fat cells is set
in your teens, and you don't grow any more after that. As one gains weight, the fat cells just fill up more and more. The book showed a microscopic picture of full fat cells swollen up like ticks.
Apparently, when one's fat cells fill up finally and there is no more room- they send out a signal that causes insulin resistance in the body.
Now, insulin is the "fat building" hormone, as well as the key to getting glucose into cells. When one's insulin levels are up after a meal, that is the signal for extra fat in the bloodstream to be packed away into fat cells.
There comes a time when the limited number of fat cells can hold no more.
They are FULL. In self defense, the fat cells cause the whole body to become insulin resistant. They can't take any more fat- so that's how it has to be. They have to become insulin resistant.
Unfortunately, this also closes the door to glucose as well, and as the other cells start to starve the body starts increasing insulin production in order to get that glucose into the cells. Which increases the fat cell's efforts to be insulin resistant. Which blocks the glucose from entering the other cells and raises blood sugar.
Which is why type II diabetics HAVE to lose weight and empty those fat cells in order to decrease the insulin resistance. Because if you just keep going- producing more and more insulin- your pancreas will eventually burn out and you'll be a type I insulin dependant diabetic as well.
What was VERY interesting, though, was what my husband said when I told him this. He immediately figured out why he's diabetic when he's only 15 lbs overweight, something that has puzzled me for a while now. (OK, he was 30 lbs over when he first hit critical- but that's really not a lot. Certainly not obese in a 6' 2" heavily muscled guy!)
He was an athlete in high school and college. A swimmer to be precise. When I first met him, he had an extremely low body fat percentage of around 3-4%. He could not float in a pool, he was that lean. He stayed that way into his early 20's.
So, his fat cell population was set at an extremely
low level. It didn't take much weight for him to reach his limit and for the fat cells to start putting out the "FULL" signal of insulin resistance.
That's why he's becoming a type II diabetic without being obese, or even very overweight. He doesn't have many fat cells, as the formative years were spent as a very, very lean person.
The book I'm reading right now is called, "Why Zebras don't get Ulcers" and despite the title and the dancing zebras on the cover- it is no light read. It's all about the biochemical changes your body undergoes during stress and how that contributes to disease. Fascinating and well written. It was in this book, rather than the diabetes specific books, that I finally understood the relationship between fat and diabetes. There are also details about how stress increases certain chemicals and makes the above reactions even worse- but I need to re-read that bit before I really understand it. It's a good blend of humor and technical detail and insightful comments. An excellent book.
Anyway, I thought it was interesting, how when your fat cells fill up- you start getting ill. Those of us with more fat cells have more leeway before an actual system malfunction happens. Those who were skinny teens and young adults can start to get seriously sick much sooner, weight-wise.