Fasting diets could increase the risk of diabetes and cause damaging side effects, new research suggests.
A group of scientists speaking at the European Society of Endocrinology’s annual meeting this weekend revealed that while fasting can help shed weight it can also impair the action of insulin – the sugar-regulating hormone – and lead to an increased risk of diabetes.
As a result, the researchers are urging people to take care before starting a weight loss programme such as the 5:2.
“This is the first study to show that, despite weight loss, intermittent fasting diets may actually damage the pancreas and affect insulin function in normal healthy individuals, which could lead to diabetes and serious health issues,” said Ana Bonassa, study author from the University of Sao Paulo in Brazil.
In order to investigate the consequences of diets like the 5:2, researchers examined the effects of fasting every other day on the body weight, free radical levels and insulin function of normal, adult rats, over a three-month period.
It found that although the rats’ body weight and food intake decreased as expected over the study period, the amount of fat tissue in their abdomen actually increased.
Furthermore, the cells of the pancreas that release insulin showed damage and there was also a presence of increased levels of free radicals and markers of insulin resistance.
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“We should consider that overweight or obese people who opt for intermittent fasting diets may already have insulin resistance, so although this diet may lead to early, rapid weight loss, in the long-term there could be potentially serious damaging effects to their health, such as the development of type-2 diabetes,” Bonassa added.
Although this new data was obtained in normal weight rats with positive effects on weight gain and food intake, the results also suggest that in the long-term harm may be caused.
As such, more investigation is needed to assess how people may be affected, particularly those with existing metabolic issues.
As a result of their findings, the researchers now plan to investigate how this kind of diet impairs pancreas and insulin function.