There remains much controversy about just how much diabetics should cut back on dietary fat, with some advocating an all-out vegan approach, while others recommend a Mediterranean diet rich in “good fats.” However, many experts believe shifting to a plant-based diet is a critical first step. One 2009 study found that blood sugar levels of Type 2 diabetics following a vegan diet of 10 percent of calories from fat, 15 percent protein, and 75 percent unrefined carbs (with no calorie limit) for 74 weeks improved considerably more than those following American Diabetes Association (ADA) guidelines that cut calories by 500 to 1,000 and more strictly limited carbohydrates. Another study of 60,000 men and women in the United States and Canada found diabetes prevalence among vegans to be just 3 percent.

A longtime vegan, Barnard recommends avoiding animal products and going easy on most vegetable oils, which often contain saturated fat along with “good fats” (for instance, olive oil is 13 percent saturated fat). On the other hand, some in the medical field have expressed concern that cutting out animal products can rob people of omega-3 fatty acids, abundant in fish, grass-fed beef, and eggs. Omega-3s actually may enhance insulin sensitivity and protect against heart disease. Another concern: “A vegan diet may be beneficial, but it’s just so hard to follow in the long-term,” says Jortberg.

A good basic guideline, she says: Stick to a plant-based meal plan that goes easy on animal products. Limit oils and fat to 30 percent of your diet (7 percent saturated), and choose healthier fats such as omega-3s, and coconut and olive oils.

What about carbohydrates? Eating too many refined carbs can certainly overtax the pancreas to the point it has trouble producing insulin. But a diet very low in carbs tends to lead people to eat excessive dietary fat. The ideal compromise, experts say: Opt for low-glycemic index carbohydrates like whole grains (such as oats, brown rice, and quinoa) and fibrous vegetables such as beans, lentils, and sweet potatoes. These convert to glucose more slowly, giving the pancreas a chance to slowly catch up on insulin production.