Type 2 Diabetes Reversed by Low Calorie Diet

AIMS/HYPOTHESIS: Type 2 diabetes is regarded as inevitably progressive, with irreversible beta cell failure. The hypothesis was tested that both beta cell failure and insulin resistance can be reversed by dietary restriction of energy intake.

METHODS: Eleven people with type 2 diabetes (49.5 ± 2.5 years, BMI 33.6 ± 1.2 kg/m(2), nine male and two female) were studied before and after 1, 4 and 8 weeks of a 2.5 MJ (600 kcal)/day diet. Basal hepatic glucose output, hepatic and peripheral insulin sensitivity and beta cell function were measured. Pancreas and liver triacylglycerol content was measured using three-point Dixon magnetic resonance imaging. An age-, sex- and weight-matched group of eight non-diabetic participants was studied.

RESULTS: After 1 week of restricted energy intake, fasting plasma glucose normalised in the diabetic group (from 9.2 ± 0.4 to 5.9 ± 0.4 mmol/l; p = 0.003). Insulin suppression of hepatic glucose output improved from 43 ± 4% to 74 ± 5% (p = 0.003 vs baseline; controls 68 ± 5%). Hepatic triacylglycerol content fell from 12.8 ± 2.4% in the diabetic group to 2.9 ± 0.2% by week 8 (p = 0.003). The first-phase insulin response increased during the study period (0.19 ± 0.02 to 0.46 ± 0.07 nmol min(-1) m(-2), p < 0.001) and approached control values (0.62 ± 0.15 nmol min(-1) m(-2), p = 0.42). Maximal insulin response became supranormal at 8 weeks (1.37 ± 0.27 vs controls 1.15 ± 0.18 nmol min(-1) m(-2)). Pancreatic triacylglycerol decreased from 8.0 ± 1.6% to 6.2 ± 1.1% (p = 0.03).

CONCLUSIONS/INTERPRETATION: Normalisation of both beta cell function and hepatic insulin sensitivity in type 2 diabetes was achieved by dietary energy restriction alone. This was associated with decreased pancreatic and liver triacylglycerol stores. The abnormalities underlying type 2 diabetes are reversible by reducing dietary energy intake.

From press report in BBC news:

An extreme eight-week diet of 600 calories a day can reverse Type 2 diabetes in people newly diagnosed with the disease, says a Diabetologia study.

Newcastle University researchers found the low-calorie diet reduced fat levels in the pancreas and liver, which helped insulin production return to normal.

Seven out of 11 people studied were free of diabetes three months later, say findings published in the journal.

More research is needed to see whether the reversal is permanent, say experts.

Type 2 diabetes affects 2.5m people in the UK. It develops when not enough insulin is produced in the body or the insulin that is made by the body doesn't work properly.

When this happens, glucose - a type of sugar - builds up in the blood instead of being broken down into energy or fuel which the body needs.

The 11 participants in the study were all diagnosed with Type 2 diabetes within the previous four years.

They cut their food intake drastically for two months, eating only liquid diet drinks and non-starchy vegetables.

Fat loss

After one week of the diet, researchers found that the pre-breakfast blood sugar levels of all participants had returned to normal.

MRI scans of their pancreases also revealed that the fat levels in the organ had decreased from around 8% - an elevated level - to a more normal 6%.

Three months after the end of the diet, when participants had returned to eating normally and received advice on healthy eating and portion size, most no longer suffered from the condition.

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It offers great hope for many people with diabetes.”
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Prof Keith Frayn

University of Oxford
Professor Roy Taylor, director of Newcastle Magnetic Resonance Centre at Newcastle University and lead study author, said he was not suggesting that people should follow the diet.

"This diet was only used to test the hypothesis that if people lose substantial weight they will lose their diabetes.

"Although this study involved people diagnosed with diabetes within the last four years, there is potential for people with longer-standing diabetes to turn things around too."

Susceptibility question

Dr Ee Lin Lim, also from Newcastle University's research team, said that although dietary factors were already known to have an impact on Type 2 diabetes, the research showed that the disease did not have to be a life sentence.

"It's easy to take a pill, but harder to change lifestyle for good. Asking people to shift weight does actually work," she said.

However, not everyone in the study managed to stay free of diabetes.

"It all depends on how much individuals are susceptible to diabetes. We need to find out why some people are more susceptible than others, then target these obese people. We can't know the reasons for that in this study," Dr Lim said.

Professor Edwin Gale, a diabetes expert from the University of Bristol, said the study did not reveal anything new.

"We have known that starvation is a good cure for diabetes. If we introduced rationing tomorrow, then we could get rid of diabetes in this country.

"If you can catch people with diabetes in the early stages while beta cells are still functioning, then you can delay its onset for years, but you will get it sooner or later because it's in the system."

But Keith Frayn, professor of human metabolism at the University of Oxford, said the Newcastle study was important.

"People who lose large amounts of weight following surgery to alter their stomach size or the plumbing of their intestines often lose their diabetes and no longer need treatment.

"This study shows that a period of marked weight loss can produce the same reversal of Type 2 diabetes.

"It offers great hope for many people with diabetes, although it must be said that not everyone will find it possible to stick to the extremely low-calorie diet used in this study."

Dr Iain Frame, director of research at Diabetes UK, which funded the study, said the diet was not an easy fix.

"Such a drastic diet should only be undertaken under medical supervision. Despite being a very small trial, we look forward to future results particularly to see whether the reversal would remain in the long term."