Articles like this one are being posted all across the internet atm.  Since breast size is also determined by many factors unrelated to diet and metabolic rate such as genetic and environmental factors many doctors believe that examining bra size is a clinical waste of time.

“Breast size is determined by a number of genetic and environmental factors. Because it is related to age at [first menstruation] and pre-pubertal growth rates that are also important determinates of obesity, breast size is probably a surrogate for the presence of obesity or the predilection to become obese.” 

“Women might get very worked up about the relation of their breast size to diabetes risk when we don’t have a substantial body of evidence to show that link.  In reality, obesity is a major determinant of risk for diabetes,” said Dr. Lewis Kuller, professor and chair in the department of epidemiology at the University of Pittsburgh.

We want women need to understand that having bigger breasts at puberty does not always mean a bigger risk for diabetes later in life.