The ketogenic diet is a low-carbohydrate, high-fat diet commonly used for rapid weight loss.
Restricting carbohydrates and increasing fat intake after a few days switches our body into the so-called. Ketosis, a metabolic condition in which the body uses primarily fats instead of carbohydrates for energy. The fact that the keto diet is effective and relatively fast, but at the same time in most cases associated with a strong JO-JO effect, is a well-known fact and I will not mention it again today.
The fact that keto or low-carb diets can be beneficial in some cases for diabetics or patients with epilepsy, for example, I leave to the explanations of specialized doctors. And the fact that there are many companies on the market selling cheap shakes made of whey protein and fat for high amounts, without addressing whether their customers will be able to take at least enough energy to cover their basal metabolism, I will leave aside now.
But I would like to mention 7 potential health risks that are real for those who use the keto diet (often repeatedly and for a long time)
1. “keto flu”
Carbohydrate intake on the keto diet is usually limited to less than 50 grams per day, which can be quite a shock to your body.
As your body depletes its carbohydrate stores at the start of this diet and switches to using ketone bodies and fats for fuel, flu-like symptoms may appear.
These include headaches, dizziness, fatigue, nausea and constipation – partly due to dehydration and electrolyte imbalances that occur as your body adjusts to ketosis.
While most people who experience the keto flu feel better within a few weeks, it’s important to monitor these symptoms throughout the diet, stay hydrated, and eat foods rich in sodium, potassium, and other electrolytes.
2. Keto diet puts a strain on your kidneys
High-fat animal foods such as eggs, meat and cheese are the staple of the keto diet. They do not contain carbohydrates. Because you eat increased amounts of these foods during your diet (those on milk protein shakes can’t help themselves), you put yourself at a higher risk of developing kidney stones.
This is because a high intake of animal foods can make your blood and urine a little more acidic, leading to increased calcium excretion in the urine.
Some studies also suggest that the keto diet reduces the amount of citrate that is released into the urine. As citrate can bind to calcium and prevent the formation of kidney stones, reduced levels may also increase the risk of kidney stones.
People with chronic kidney disease should avoid this diet altogether, as weakened kidneys may not be able to remove the accumulated acids in the blood. These are the result of metabolism of higher amounts of animal foods. This can, in the worst case, lead to a state of acidosis, which can worsen the progression of chronic kidney disease.
3. Digestive problems and undesirable changes in the intestinal microflora.
Since the keto diet restricts carbohydrates, it is quite difficult to meet your daily fiber needs.
Some of the richest sources of fibre, such as high carbohydrate fruits, starchy vegetables, whole grains and beans, are excluded from the keto diet because they provide too many carbohydrates.
As a result, the keto diet can lead to digestive problems and constipation.
For example, a 10-year study of children with epilepsy on a ketogenic diet showed that 65% of them reported constipation as a common side effect.
In addition, fibre nourishes the beneficial bacteria in the intestines. A healthy gut helps boost immunity, improve mental health and reduce inflammation. In short, the gut microbiome is becoming increasingly important and reputable in modern medicine and if it is suffering from a long-term lack of appropriate nutrients (fibre and possibly other undigested complex carbohydrates), we can realistically expect health problems associated with insufficient or poor gut microbiota function.
But to be completely objective, current research and studies are not entirely clear on this issue. Many other things can have a negative effect on the gut microbiota, and it is not easy to organise a truly objective study with an unquestionable conclusion in this area.
Some of the keto-friendly foods that are high in fiber include flaxseeds, chia seeds, coconut, broccoli, cauliflower, and leafy greens.
4. Deficiency of certain important nutrients
Because the keto diet restricts a wide range of foods, especially nutrient-dense fruits, whole grains and legumes, it can often cause deficiencies in the recommended amounts of vitamins and minerals.
In particular, some studies suggest that the keto diet does not provide enough calcium, vitamin D, magnesium and phosphorus.
A study that evaluated the nutrient composition of common diets revealed that very low-carbohydrate diets, such as the Atkins diet, which is similar to the keto diet, provide sufficient amounts of only 12 of the 27 vitamins and minerals our bodies need to obtain from food.
This can lead to various health problems over time.
It’s certainly worth noting that guidelines for doctors who guide people on a very low-calorie keto diet for weight loss recommend supplementing with potassium, sodium, magnesium, calcium, omega-3 fatty acids, psyllium fiber, and vitamins B, C, and E. So keep in mind that the nutritional adequacy of this diet depends on the specific foods you eat. A diet rich in healthy, low-carb foods such as avocados, nuts and non-starchy vegetables provides more nutrients than processed meats and keto shakes/snacks.
5. Dangerously low blood sugar
This point is more relevant only for diabetics. Low-carbohydrate diets such as keto have been shown to help control blood sugar levels in people with diabetes.
In particular, some studies suggest that keto can help lower hemoglobin A1c, an indicator of average blood sugar levels.
In individuals with diabetes 1. type, however, there may be a high risk of more frequent episodes of low blood sugar (hypoglycaemia), which is manifested by confusion, shivering, fatigue and sweating.
A study of 11 adults with diabetes 1. type who followed a ketogenic diet for more than 2 years found that the average number of low blood sugar episodes was close to 1 per day.
In individuals with diabetes 1. type, low blood sugar usually occurs if they take too much insulin and do not consume enough carbohydrates. A low-carbohydrate keto diet may therefore increase this risk.
Theoretically, this could also happen to individuals with diabetes 2. type who are taking insulin medication.
6. Risk of bone health effects
The keto diet is also associated with poorer bone health.
Several animal studies have linked the keto diet to reduced bone strength, possibly due to the loss of bone mineral density that can occur as the body adapts to ketosis. Not to just refer to animal studies, a six-month study of 29 children with epilepsy on the keto diet found that 68% of them had lower bone mineral density scores after switching to the diet.
Another study of 30 elite walkers found that those who followed a keto diet for 3.5 weeks had significantly higher levels of blood markers of bone loss compared to those who ate a higher carbohydrate diet.
But here again, in the interest of objectivity, we should wait for more and bigger studies on the keto diet and its effect on bone mineral levels.
7. Risk of chronic diseases
The effect of the ketogenic diet on the risk of chronic diseases such as heart disease or cancer is hotly debated and not fully understood.
Some evidence suggests that high-fat, low-carbohydrate diets that focus on animal foods can lead to poor health outcomes, while diets that emphasise plant sources of fat and protein provide benefits.
A long-term observational study of more than 130 000 adults has linked a low-carbohydrate diet based on animal foods to higher rates of death from heart disease and cancer.
Conversely, a low-carbohydrate, plant-based diet was associated with lower rates of death from heart disease and cancer.
Another study of more than 15 000 adults found similar results, but linked both low-carbohydrate and high-carbohydrate diets to higher rates of all-cause mortality compared with a moderate-carbohydrate diet in which carbohydrates accounted for 50-55% of total daily calories.
Again, however, the available studies do not answer many questions, and it would be unfair to link the increased incidence of cardiovascular disease and various cancers to a low-carbohydrate diet alone.
Conclusion
I leave it up to you to decide whether to use the keto diet for weight loss, but before you do, it’s good to see not only the potential benefits, but also all the potential risks.
I would definitely not recommend keto to people who have kidney problems or low calcium levels in their bones.
A healthy person can probably do the keto diet in the short term without any major harm (unless you count the “keto flu” that almost everyone gets. In the long run, and in terms of healthy and balanced eating, I definitely don’t see a path in the keto diet.
Reference:
- PMC – Pub Med Central: Ketogenic diets boom or bane, Ketogenic diets: boon or bane? – PMC (nih.gov)
- PMC – Pub Med Central: Ten-year single-center experience of the ketogenic diet: factors influencing efficacy, tolerability, and compliance, Ten-year single-center experience of the ketogenic diet: factors influencing efficacy, tolerability, and compliance – PubMed (nih.gov)
- PMC – Pub Med Central: Ketogenic Diet and Microbiota: Friends or Enemies?, Ketogenic Diet and Microbiota: Friends or Enemies? – PMC (nih.gov)
