Ketogenic diets are those with a very low amount of carbohydrates. They can be a strategy for treating people who have seizures, however, and today they have been used for weight loss and diseases such as diabetes.
But is this diet really beneficial? A review published in the journal Frontiers in Nutrition evaluates the pros and cons of ketogenic diets for some health conditions, as well as the impact on food quality.
Understand more about the ketogenic diet
As I said, the ketogenic diet refers to a diet that is very low in carbohydrates (generally less than 50 g, which is very little considering that the guidelines for an adult are to consume, on average, 130 g of this nutrient), modest in protein and rich in fat.
This combination aims to induce the production of ketone bodies or ketones. Ketone bodies are products of the conversion of fats to glucose that serve as an alternative source of energy.
When glucose levels are low, the body produces ketone bodies so it can use fat as an energy source.
This mechanism can happen in people with uncontrolled diabetes, but also in everyone, when we go without food for some time.
A certain amount of ketone bodies circulating in the body is normal, but very high levels can generate toxicity, increasing the risk of ketoacidosis.
What is the impact of the ketogenic diet on food quality?
Now let’s go to the published review. One of its goals was to analyze the effects of the ketogenic diet on food quality.
Among the findings, the researchers point out that extreme carbohydrate restriction can profoundly affect the quality of food, by reducing or eliminating fruits, vegetables, cereals and legumes, food groups that have vitamins, minerals, fiber and phytochemicals (such as flavonoids, which are natural antioxidants).
Thus, these diets can lead to nutritional deficiencies, as they are generally low in vitamins B1, B6, A, E and folic acid, calcium, magnesium, iron and potassium.
As for the fact that the ketogenic diet is low in fiber, it is worth remembering that they are not only necessary for the proper functioning of the intestine, but also serve as food for the intestinal microbiota, which can produce effects such as: increased absorption of nutrients, stimulation release of satiety hormones, improved immune function and anti-inflammatory and anticancer actions.
One of the studies reviewed even shows that the relative abundance of certain bacteria in the gut microbiota is reduced in children who consume a ketogenic diet in order to treat seizures. In addition, because they have a large proportion of foods of animal origin, ketogenic diets often contain excess saturated fat.
Effects of Ketogenic Diets on Some Health Conditions
As for the effects of ketogenic diets, the researchers found that they may not be safe for pregnant women, as they are associated with a higher risk of the baby having neural tube defects, even if the woman receives folic acid supplementation, as recommended during the gestation.
One of the evaluated studies, the National Birth Defects Prevention Study, showed that women who reported consuming low-carb diets in the year before conception were more likely to have a child with neural tube defects. As for unplanned pregnancy, this risk was even greater.
In patients with diabetes, the results are controversial. An improvement in glycemia in the short term seems to be possible, but in the long term benefits of the ketogenic diet have not been elucidated.
Because it is high in protein, this diet can also accelerate the development of kidney failure in patients with kidney problems. For people without chronic kidney disease, one of the biggest risks is the development of kidney stones.
Another risk would be to increase “bad” cholesterol (LDL cholesterol) in some patients, which can contribute to the development of cardiovascular disease.
Researchers also point out that carbohydrate restriction leads to consumption of foods that may be associated with an increased risk of developing heart disease, cancer, diabetes and Alzheimer’s.
The review also shows that the ketogenic diet is not about losing weight. In the short term there may even be a loss of weight, but in the long term it is not more effective than other strategies. Also, they are not sustainable in the long term, as it is difficult to go without carbohydrates for a long time, our bodies need them.
Finally, ketogenic diets have been linked to an increased risk of mortality from all causes, although the data suggest that they may be associated with a greater or lesser risk of mortality depending on the types of carbohydrate, protein (animal or vegetable) and fat (saturated or unsaturated).
Ketogenic diet? just to treat epilepsy
The researchers concluded that the only well-founded use for ketogenic diets is to reduce seizure frequency in some people with drug-resistant epilepsy. But even so, not without effects, because in these cases ketogenic diets can cause fatigue, headaches, nausea, constipation, hypoglycemia, ketoacidosis.
In addition, a study of 300 volunteers who adhered to ketogenic diets of their own volition showed that they can be temporarily accompanied by flu-like symptoms, such as headache, fatigue, nausea, dizziness, intestinal discomfort, lack of energy, feeling faint and changes in heart rate.
It is not surprising that ketogenic diets can cause so many adverse effects, since it is a restrictive diet. And as we know, the body and brain hate diets!
Instead of looking for a miracle diet such as ketogenic, which is advertised around the world as a true panacea, look for a healthy lifestyle: practice a pleasurable physical activity, sleep well, learn to deal with stress and adopt healthy eating habits. As portrayed in the book “The 7 Pillars of Food Health”, good food health involves much more than just eating.
By that, I mean that you should eat everything (no restrictions!), with pleasure, listening to your body, honoring your hunger and building a peaceful relationship with food!