Patients who reverse their diabetes and then keep their weight down can remain free of the condition, British research has found.
The study found even people who have had type 2 diabetes for up to 10 years can reverse their condition after adopting a very low kilojoule diet.
Professor Roy Taylor, a world expert on the condition, published his latest findings in the journal Diabetes Care.
The professor of medicine and metabolism at Newcastle University has previously shown patients with type 2 diabetes who successfully lose weight can reverse their condition because fat is removed from their pancreas, returning insulin production to normal.
A study led by Prof Taylor five years ago showed diabetes could be reversed by a very low kilojoule diet.
International interest was sparked but the study lasted only eight weeks and the question remained whether the diabetes would stay away.
In this new study, 30 volunteers with type 2 diabetes embarked on the same diet of 2500 to 2900 kilojoules a day.
Participants lost on average 14 kilograms. They did not regain any weight during the next six months.
The group included many people with longer duration diabetes, defined as more than eight years and ranging up to 23 years.
Overall, 12 patients who had had diabetes for less than 10 years reversed their condition and six months later they remained diabetes-free.
In fact, after six months a 13th patient had reversed their diabetes.
Though the volunteers lost weight, they remained overweight or obese but they had lost enough weight to remove the fat out of the pancreas and allow normal insulin production.
"What we have shown is that it is possible to reverse your diabetes, even if you have had the condition for a long time, up to around 10 years," Prof Taylor said.
"If you have had the diagnosis for longer than that, then don't give up hope - major improvement in blood sugar control is possible.
"The study also answered the question that people often ask me - if I lose the weight and keep the weight off, will I stay free of diabetes? The simple answer is yes.
"Interestingly, even though all our volunteers remained obese or overweight, the fat did not drift back to clog up the pancreas.
"This supports our theory of a Personal Fat Threshold.
"If a person gains more weight than they personally can tolerate, then diabetes is triggered, but if they then lose that amount of weight then they go back to normal."
A larger trial involving 280 patients has started to see how successfully people can reverse their diabetes through weight loss under the care of their family doctor and nurse.
