One of the most popular types of weight-loss diets today is the Ketogenic diet — a diet that’s high in fat and low in carbohydrates. Such diets are in vogue today but they may increase the risk of diabetes, research suggests. The findings are reported in the Journal of Physiology.
The study revealed that –
- A ketogenic diet is known to lead to weight loss and is considered metabolically healthy; however, there are conflicting reports on its effect on hepatic insulin sensitivity.
- KD fed animals appear metabolically healthy in the fasted state after 3 days of the dietary challenge, whereas obesogenic high-fat diet (HFD) fed animals show elevated insulin levels.
- A glucose challenge reveals that both KD and HFD fed animals are glucose intolerant.
- Glucose intolerance correlates with increased lipid oxidation and lower respiratory exchange ratio (RER); however, all animals respond to glucose injection with an increase in RER.
- Hyperinsulinaemic–euglycaemic clamps with double tracer show that the effect of KD is a result of hepatic insulin resistance and increased glucose output but not impaired glucose clearance or tissue glucose uptake in other tissues
Ketogenic diets date back to the 1920s but have soared in popularity in the last few years. The hypothesis is that such a diet will force the body to burn fat as fuel, leading to rapid weight loss. Part of their attraction is that they allow the dieter to eat large quantities of fat-rich food such as meat, butter and cheese. n addition to weight loss, ketogenic diets are also supposed to keep blood sugar levels stable.But new research suggests this claim at least could be misconceived.
In the study, the researchers fed mice a ketogenic diet for several days and found that the liver began resisting insulin almost immediately and the mice were unable to regulate their blood sugar levels after only three days on the diet. In fact, insulin resistance is a stepping stone to Type 2 diabetes.
Lead researcher Prof Christian Wolfrum, from ETH Zurich University in Switzerland, 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 metabolised, their products might have important signalling roles to play in the brain.”
The ketogenic diet was first developed as a treatment for resistant epilepsy initially when doctors discovered that a low-carb diet appeared to help reduce seizures, possibly by altering the supply of energy to the brain. A ketogenic diet mimics what happens when the body is starved of carbs. The liver is forced to use fat for fuel, converting it to “ketone bodies”, molecules that provide an emergency glucose substitute based on acetone.
Most ketogenic diets provide 70 per cent or more calories from fat, 15-20 per cent from protein, and 10 per cent or less from carbohydrates. Experts feel that more research is needed to confirm the effects in humans as present study has been done in mice but the work suggests that the diet could have health risks for humans.
For further readng log on to : DOI: 10.1113/JP275173