Ketogenic diets – diets that are low carbohydrate high fat eating plans and that are known to lead to weight loss – may cause an increased risk of Type 2 diabetes in the early stage of the diet.
Findings from the study published in the Journal of Physiology raise concerns about whether or not ketogenic diets are actually healthy.
The study, which was conducted by ETH Zurich in conjunction with University Children’s Hospital Zurich, involved feeding mice two different types of diet (a ketogenic diet and a high fat diet, which causes the liver to become resistant to insulin) and then performing standard metabolic tests on them. Using specialized procedures the researchers were able to determine the effects of internal sugar production from the animal (mostly the liver), and sugar uptake into tissues (mostly the muscle), during insulin action.
Insulin is released in the blood and used to control blood sugar levels including signaling the liver to stop producing sugar. If this system is impaired and the body does not use insulin properly, which is called insulin resistance, individuals are likely to develop high blood sugar levels. In this study the researchers showed that for ketogenic diets this process for controlling blood sugar levels does not work properly and there was insulin resistance in the liver. When the liver is unable to respond to normal levels of insulin to control blood sugar levels this may lead to an increased risk of Type 2 diabetes.
It is important to note that the research did not analyse whether the diet employed causes obesity, if given long term. The mechanism behind the whole process was undetermined; therefore, the existence of a shared physiological response between low carb and regular carb high fat diets that cause insulin resistance in the liver requires further exploration.
Christian Wolfrum, one of the corresponding authors on the paper said: “Diabetes is one of the biggest health issues we face. Although ketogenic diets are known to be healthy, our findings indicate that there may be an increased risk of insulin resistance with this type of diet that may lead to Type 2 diabetes. The next step is to try to identify the mechanism for this effect and to address whether this is a physiological adaptation. Our hypothesis is that when fatty acids are metabolized, their products might have important signalling roles to play in the brain.”