Q: Can Type 2 diabetes be reversed? My son was recently diagnosed with it, but I'm not sure he's taking it seriously enough.

A: I understand your concern: Clearly, your son -- and everyone with diabetes -- should do whatever they can to combat the disease.

Chronically elevated blood sugar leads to atherosclerosis, increasing the risk of heart attacks, strokes and vascular disease in the legs. It also damages the nerves and kidneys, leading to a loss of sensation and kidney failure. Controlling the disease, though difficult, is not impossible and should be paramount.

Even reversing the disease is doable. As proof, consider the effects of bariatric (weight loss) surgery among people with Type 2 diabetes. They quickly go into remission.

If surgery seems too dramatic, consider the nonsurgical evidence from a 2015 study in which 29 patients consumed a liquid diet of 624 to 700 calories per day for eight weeks. In the United States, the reported average caloric intake for a man is 2,600 and in women it is about 1,800; for people with Type 2 diabetes, it's often much higher. After eight weeks of calorie restriction, the average study participant lost about 32 pounds.

Among those who had diabetes for less than four years, 87 percent reversed their fasting blood sugars to non-diabetic levels. Among those who had diabetes for more than eight years, 50 percent were able to reverse blood sugars to non-diabetic levels. Blood pressure and cholesterol numbers also improved and the participants were able to tolerate the calorie restriction well.

A 2016 study looked at what happened to these patients after they returned to a normal-calorie diet. All participants received dietary counseling and, six months after the initial start of the study, they had regained -- on average -- only 2 pounds of the 32 pounds they lost during fasting.

Those who had reversed their diabetes were able to maintain their blood sugar at the same level even after returning to a normal-calorie diet. Even those who were not able to reverse their diabetes had lower blood sugar levels than before the study.

A current study that won't have complete data until 2018 has followed 140 patients who adhered to 12 weeks of an 825-to-853 calorie diet; it will follow them as they then try to maintain a balanced diet for the next 92 weeks. The results are expected to give Type 2 diabetics hope of reversing diabetes with initial calorie restriction, followed by a balanced diet.

These are tightly controlled university studies and may be difficult to replicate outside of a well-conducted clinical trial. However, newly diagnosed Type 2 diabetic patients eventually may be given directions for a low-calorie diet, followed by a diet overseen by a nutritionist.

In the meantime, to reverse his diabetes, your son needs to start by eliminating foods with added sugar. This seems obvious, but it takes self-control. Cookies, candies, cakes, doughnuts, ice cream, sodas and juices should have no place in his diet.

He should also stay clear of low-fiber carbohydrates, especially snack foods.

If he's diligent with his diet, he can reverse a disease that has become an epidemic within our country.

So the answer is: Yes, Type 2 diabetes can be reversed, as can the obesity that leads to it. But reality itself isn't that simple.

• Robert Ashley, M.D., is an internist and assistant professor of medicine at the University of California, Los Angeles.Send your questions to askthedoctors@mednet.ucla.edu.