If I wanted to find out if I could reverse the progressive development of type 2 diabetes with energy restriction, I would conduct a clinical trial.
I would need a group that reduced their energy intake, but if I wanted to make sure an effect wasn’t caused by the reduction in a specific macronutrient (and if I had the recourses) I would need more groups; one who reduced fat intake while keeping calories stable, one reduced proteins and one who reduced carbohydrates. I still couldn’t be sure if an effect was due to a specific macronutrient – it could just as well be because of the relationship between nutrients – but I would be more sure.
Now, recourses are usually sparse but a study could be done with only one group also. I would just have to make very sure to write in the discussion that an effect could be due to the specific lowering of one nutrient as opposed to lowering of total calories.
A group of researchers at Newcastle University did the above mentioned study. They hypothesized that
“…both beta cell failure and insulin resistance can be reversed by dietary restriction of energy intake.”
To test the hypothesis, eleven people with type 2 diabetes ( mean BMI 33.6, nine male and two female) were studied before and after 1, 4 and 8 weeks of a 600 kcal)/day diet.
600 kcal is not much and as Peter at Hyperlipid noted, one of the participants found the diet difficult to handle:
«It was very tough. I was hungry all the time. It was a starvation diet and food was on your mind all the time,»
said Gordon, the retired lorry driver.
This was actually a study that looked at beta cell function, and it came to be because one of the authors had read about the miraculous healing of T2D that occurs with bariatric surgery.
Writes Lim et al
“However, type 2 diabetes is clearly reversible following bariatric surgery. The normalisation of plasma glucose concentration follows within days of surgery, long before major weight loss has occurred…”
Which means the pathology of T2D is not caused by overweight itself, because the normalization of glucose is vital in losing the T2D diagnosis.
The experimental diet was a liquid diet formula (46.4% carbohydrate, 32.5% protein and 20.1% fat, 510 kcal/day) sponsored by Nestlé Nutrition. This was supplemented with three portions of non-starchy vegetables so that total energy intake was about 600 kcal/day.
I won’t dwell on the details; it’s an open access article so anyone can read.
Anyway, the diet caused a significant reduction in plasma glucose (9.2 to 5.9 mmol/l) and insulin (151 to 73 pmol/l after 1 week and to 65 pmol/l by 8 weeks.
These remarkable changes happened after just one week, before much fat was lost (2,4kg), confirming that T2D is not caused by overweight.
|From Lim et al 2011
“In the first 7 days of the reduced energy intake, fasting blood glucose and hepatic insulin sensitivity fell to normal, and intrahepatic lipid decreased by 30%.”
“…supports the accumulating information on the inhibitory effect of fatty acids on insulin secretion in vitro and in vivo and is the first direct evidence in humans that the beta cell defect of type 2 diabetes is reversible by sustained negative energy balance. Prolonged elevation of plasma fatty acids in humans decreases insulin secretion, and it has previously been shown that there is an association between pancreatic fat content and type 2 diabetes. Prior to the onset of spontaneous diabetes in rodents, both total pancreatic fat and islet triacylglycerol content increase sharply. In vitro, chronic saturated fatty acid exposure of beta cells inhibits the acute insulin response to glucose, and removal of fatty acids allows recovery of this response.”
They may be right, in that fatty acids all over the place are to blame, but I still don’t see the need for starvation. What about just reducing carbs? It has been done before, and it has also been found to cure diabetes, despite ad libitum eating. No need for starvation.
The discussion chapter includes the necessary limitations section, where the authors are supposed to say something about the role the different macronutrients has on the pathology discussed and whether the effects can be attributed to the reduction in one of these. But there is no such discussion. Starvation cures diabetes.
Writes Lim et al
“This study demonstrates for the first time the time course of a return of normal beta cell function and hepatic glucose output by acute restriction of dietary energy intake in individuals with type 2 diabetes.”
“This new insight allows an understanding of the causality of type 2 diabetes in individuals as well as in populations.”
In other words; diabetes is caused by eating to damn much. Because eating less cures it.
Lim EL, Hollingsworth KG, Aribisala BS, Chen MJ, Mathers JC, Taylor R: Reversal of type 2 diabetes: normalisation of beta cell function in association with decreased pancreas and liver triacylglycerol. Diabetologia 2011.