Canadian researchers had the idea to look at the correlation between the risk for developing Type 2 diabetes and the size of women's breasts. They concluded that a larger cup size at age 20 was a greater risk for developing type 2 diabetes in your 40s.
I thought, now wait a minute! Larger breasts (the real thing, that is) usually go with a larger waist circumference, a known risk for type 2 diabetes. Women with larger breasts also tend to weigh more, don't they? They also generally carry more fat tissue, making breast size a hard to single out factor.
Not surprisingly, researchers themselves would like to do more studies to be able to use cup size as an independent predictor of risk.
You can read the full study, here.
p.s. Meanwhile, I asked my endocrinologist about this and he said oh yes most of his type 2 diabetes patients were large breasted, with more fat tissue and heavier on top as a whole.