What is the ketogenic diet
The ketogenic diet is characterized by being very low in carbohydrates, between 20 g and 50 g per day . Less than 10% of the energy we consume daily would come from them, when under normal conditions they represent at least 50% of our diet.
“In general, the ketogenic diet includes many meats, eggs, processed meats, sausages, cheeses, fish, nuts, butter, oils, seeds, and fibrous vegetables,” says Pablo Ojeda, a dietitian specializing in eating disorders and obesity.
On January 20, a study was published in Nature Metabolism in which the effect of a very strict ketogenic diet was seen in a group of mice. The diet consisted of 99% fat and 1% carbohydrates.
What was observed is that, at the beginning of following this diet, the risk of diabetes and inflammation was reduced and your metabolism improved . After a week, the mice showed a reduction in blood sugar levels and inflammation. However, what the researchers found was that when the body is in this mode of ingesting 99% fat and 1% carbohydrates, in addition to the breakdown of fat, fat storage also takes place. When the mice continued the high-fat, low-carbohydrate diet beyond a week, they consumed more fat than they could burn, and they developed diabetes and obesity.
The food technologist and dietician-nutritionist, Beatriz Robles, points out that studies like this, based on animals and not on humans, cannot be used to make recommendations to the population. They can serve as a starting point, but up to there. In their opinion, the quality of the evidence from this study is very low.
Side effects of the ketogenic diet
“One of the main criticisms of this diet is that many people tend to eat too much protein and low-quality fat from processed foods, with too little fruits and vegetables . Patients with kidney disease should be cautious because this diet could make their condition worse. Also, some patients may feel a little tired at first, while others may have bad breath, nausea, vomiting, constipation and trouble sleeping, ”says Pablo Ojeda.
Robles, for his part, points to the lack of fiber that generally occurs if you follow a ketogenic diet. Furthermore, “all the compounds that have some physiological activity and come from foods such as fruits and legumes, we are not going to obtain it,” he points out. An example would be antioxidants, present in fruits.
The benefits of the ketogenic diet under review
Two of the benefits attributed to the ketogenic diet are weight loss and reduced cardiovascular risk. For Beatriz Robles there are no significant differences between adopting this diet or another one focused on the same objectives , that is, if it were possible to follow a ketogenic diet for a year, something quite complicated due to the fact that its enormous carbohydrate restriction makes most people give it up, the weight lost would be similar.
Another benefit attributed to the ketogenic diet is that it allows control of blood glucose in type 2 diabetes. “It could improve glycemic control but the quality of the evidence is so low that it cannot be generally recommended .”
There has also been talk that this diet can benefit cancer patients. Again Robles points out: “ There is no scientific evidence in cancer patients . Yes there are indications that some cases might be helpful, but there is no robust evidence. Randomized controlled trials would be needed to generate higher quality evidence ”.
In this sense, Pablo Ojeda tells us that more and more studies are being done to see if the ketogenic diet can help cancer patients . “Without a doubt, there are more and more studies in this line. Early research published in the journal Cell Reports suggests that restricting blood sugar could also help fight certain cancerous tumor growths . “
“Researchers at the University of Texas at Dallas restricted blood sugar levels in mice (not humans) by feeding them a ketogenic, high-fat, moderate-protein, low-carbohydrate diet and giving them a drug to diabetes that prevents the kidneys from reabsorbing glucose into the blood. The combination of the diet and the diabetes drug did not reduce lung and esophagus cancers in the mice, but it did prevent them from progressing . Both the ketogenic diet and the pharmacological restriction of blood glucose inhibited the growth of squamous cell carcinoma tumors in mice with lung cancer. Both elements also showed promise independent of each other, the key finding of this study in mice is that a ketogenic diet alone has some inhibitory effect on tumor growth in squamous cell cancer. When we combined this with the diabetes medicine and chemotherapy, it was even more effective, “Ojeda tells us.
“I don’t think we should reject the keto diet outright. It is possible that the scientific evidence with the passage of time is more robust and that in some pathologies it can be proposed as a therapy or as a therapeutic approach, but at this time and in a general way of course not ”, points out Robles.
So ketogenic diet yes or no?
The world of nutrition is by no means alien to fads and the ketogenic diet is, in most cases, one more example of this. As Pablo Ojeda points out, better than joining the diet of the moment, which lasts a few weeks or months, “we must try to adopt a change that is sustainable in the long term. A balanced and unprocessed diet, rich in very colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds and olive oil ” . In addition, the expert reminds us that yo-yo diets, in which you lose weight quickly, are associated with higher mortality.
Knowing the side effects that a ketogenic diet can have, which cannot be recommended to the general population, as well as the lack of strong scientific evidence to support it, our advice is that if you want to follow it, put yourself in the hands of a expert.
