Truth: Eating sugar, in and of itself, does not cause type 2 diabetes, says David Grotto, a registered dietitian in Illinois and author of 101 Optimal Life Foods. The real diet culprit is excess calories, experts believe. Too many calories equals too much fat in the body, particularly around the stomach, and that fat prevents insulin from transporting glucose to cells, where it’s needed for energy, Grotto explains. In response, the pancreas pumps out more insulin. Over time, the pancreas can’t produce enough insulin, and what it does produce is no longer as effective. It is this insulin resistance that is a precursor to diabetes. Of course, excess calories aren’t the only trigger for the disease (type 1 is caused by genetics and unknown factors, not diet). Type 2 diabetes is also associated with lack of adequate exercise and older age. There’s also a genetic component: Certain ethnic groups (blacks, Latinos, Native Americans, Asian Americans and Pacific Islanders) and people with a strong family history are at risk -- even if they’re not overweight.