With commentary by Roy Taylor, MD, MBChB, professor of medicine and metabolism, Newcastle University, U.K.
Reversing type 2 diabetes, at least for some, might be possible by following a very low-calorie diet and then keeping that weight off, even if they're still overweight or obese, says a U.K. doctor who has been researching the idea for several years.
Roy Taylor, MD, MBChB, professor of medicine and metabolism at the Newcastle University, knows he has some convincing to do. "Old ideas die hard," he says. While several studies have now found that bariatric surgery and the resulting weight loss can reverse type 2 diabetes, Dr. Taylor's regimen involves no surgery.
In his most recent report, published in Diabetes Care earlier this year, he found that 12 of 30 volunteers with type 2 diabetes reversed their diabetes and remained free of the condition six months later. At the six-month mark, the 13th participant had a reversal.1
The 12 responders had fasting blood glucose levels below 7 mmol/L (or 126 mg/dl), defined as the start of diabetes, after returning to a normal diet, he found. Those who responded tended to have had the diagnosis a shorter period of time and had higher insulin levels at the study start. Now, Dr. Taylor is in the middle of yet another study, hoping to eventually enroll 280 to follow the plan.
For the recently published study, Dr. Taylor and his team enrolled 30 men and women who had been diagnosed with type 2 diabetes 6 months to 23 years earlier. They all stopped their diabetes medicine at the beginning of the study. They ate a daily diet of 600 to 700 calories. They lost, on average, about 30 pounds (14 kilograms). Even with the weight loss, they stayed overweight or obese.
The secret? Dr. Taylor says it's all about a concept called a personal fat threshold. "When a person has more fat than they can safely store under the skin, then it spills over into the important organs," he says. "With substantial weight loss (around 15% of body weight) this harmful fat in the liver and pancreas is removed and the function of these organs goes back to normal."
That personal fat threshold, in Dr. Taylor's view, can also explain why some people with body mass indexes or BMIs in the ''healthy'' weight range develop type 2 diabetes. In an earlier study, published in 2011 in Diabetologia, Dr. Taylor found similar results. 2
In a new study, Dr. Taylor is continuing to look at how diet can reverse diabetes. The two-year study is funded by Diabetes UK. Participants will follow a very low-calorie plan for 8 weeks, drinking 3 diet shakes a day, along with 240 grams (about 8 ounces, half a pound) of non-starchy vegetables, totaling 600 to 700 calories.3
Next, the volunteers slowly return to a normal eating pattern over a two-week transition period, getting individualized advice about how much to eat to maintain their loss over the next six months. The participants are seen once a month over the study period. When they get off the shake regimen, in general, they eat about a third less than they did before starting the study.
"Within the next two months, we shall complete recruitment," Dr. Taylor says. "The study is being done entirely in primary care. A far higher percent of people with type 2 diabetes are willing and able to lose weight than most doctors would guess."
First-year results are due by summer of 2017, Dr. Taylor says, and the team will publish preliminary results after that.
U.S. Doctor Weighs In
The concept that diabetes may be ''reversible'' is not new, says Jill Crandall, MD, director of the Diabetes Clinical Trials Unit at Albert Einstein School of Medicine, the Bronx, who reviewed the findings of the latest U.K. study.
"It's been observed many times that some overweight people who lose weight can have normalization of blood sugar levels and can stop taking diabetes medicine. This has been shown repeatedly from studies of patients having bariatric surgery or form other short-term diet studies," Dr. Crandall says.
The rub? "Losing weight—and keeping it off—is a major challenge and relatively few patients succeed."
She calls the newest study results interesting, but not surprising. "As you might expect, the people who 'responded' were younger, had lower blood sugar and a shorter duration of diabetes at baseline—all factors that indicated they had less severe diabetes to begin with. And so their metabolic defect was more reversible," she says.
What remains to be shown, she says, is if the blood sugar levels will remain normal over a longer time period.