One way the glitazone drugs like Avandia and Actos work is by stimulating more stem cells to differentiate into fat cells. This can make patients gain weight. But the new baby fat cells are much less insulin resistant than the old stuffed fat cells, and they take up more glucose and keep blood glucose levels down.
One problem with this is that because the stem cells are producing more fat cells, they're producing fewer bone cells, and these drugs can increase your risk of osteoporosis. As with so many drugs, it's a trade-off of a benefit here and a loss there.
There's another way this competition for stem cell differentiation can affect us. Reporting in the Proceedings of the National Academy of Sciences, researchers say that when blood glucose (BG) levels are high, more stem cells differentiate into fat cells and fewer differentiate into muscle or beta cells.
This makes sense. If an organism senses that food is plentiful (lots of food makes BG levels go up), it figures it may need more fat cells to store this windfall of calories. This strategy makes sense in a world where most people don't have enough to eat and it's important to store energy when you can.
But in our world, this means that if you eat too much, especially carbohydrates, and your BG level goes up, you're going to produce more fat cells, which will make you fatter and more insulin resistant, which will make your BG levels go up even more, and you're caught in a terrible vicious circle.
It's yet-another reason it makes sense to control your BG levels. One way to do this is to avoid eating a lot of carbohydrates. If you simply can't bring yourself to give up your favorite foods, then do whatever it takes to keep your BG levels close to normal levels.
But if that requires 5 or 6 different powerful drugs, keep the results of the ACCORD study in mind. In that study, elderly patients with many heart disease risk factors actually did worse (had more fatal heart attacks) when they were aggressively treated to keep their BG levels down. Another study (ADVANCE) contradicted those results, but we don't yet know why and won't until the details of both studies are published.
Until then, it makes more sense to keep your BG levels down by limiting your carbohydrate intake (be sure to consult your doctor about this first). By doing so, you should reduce your risk of many complications, and now we know you'll reduce the production of more fat cells as well.