What are the side effects of the ketogenic diet? (and how to solve them)

Published February 3, 2022·Mattia D.

While the ketogenic diet is proven to be very effective in weight loss, it may cause some nasty side effects.

Some side effects that may arise in the diet are:

Thirst
Fatigue
Constipation / Diarrhea
Hunger
Anxiety or irritability
Tachycardia
Kidney stones
Increase in blood cholesterol

Below we will see specifically the most common side effects (and how to solve them).

PS: it is good to specify that the following article is for informational purposes only. Before making any changes to your diet, it is advisable to consult your doctor or a specialized nutritionist.

Short term side effects

The short-term effects are mainly caused by what is called keto flu.

This is an adaptation phase after which you will notice improvements, including an increase in energy and concentration as well as a decrease in "cravings" as well as the need for sweets and carbohydrates.

1. Thirst

Since most fluids are absorbed with the help of carbohydrates, with the ketogenic diet these fluids are lost very quickly in the initial period, causing dehydration and consequently thirst.

How to solve the problem? Obviously increasing hydration by drinking more water is the most obvious solution, but increasing your sodium and potassium intake is also important to avoid fatigue (point 2).

2. Fatigue

Fatigue is a symptom often reported in the early days of the ketogenic diet, causing fluid loss.

How to fix this? Increasing your sodium and potassium intake should handle fatigue easily. Specifically, increasing the consumption of vegetables should help with this symptom.

3. Constipation

Constipation could be a side effect if fiber sources previously provided by various grains or starches are not replaced with other low-carb fiber sources such as vegetables.

How to fix it? By simply increasing the fiber intake from low-carb vegetables or fruits, for example: salad, cabbage, radicchio, endive, chicory, avocado and berries (in moderation).

4. Diarrhea

In contrast to constipation, diarrhea could be another side effect of the ketogenic diet. In fact, the increased consumption of fat in the diet could cause the liver to release bile, which is a natural laxative.

How to fix it? If the problem is caused by excessive consumption of fats, reducing fat should solve the problem. Specifically, the remedies could be the elimination (or reduction) of the consumption of ketogenic sweets, or the reduction of added fats such as butter or coconut oil in food.

If that doesn't help, consuming probiotics should be able to handle the problem (sauerkraut is a great source of pre and pro biotics when eaten raw).

5. Hunger

Your body will most likely not initially be used to use ketones as an energy source causing an increased need for carbohydrates.

How to solve the problem? Increasing the intake of soluble fiber should increase the feeling of satiety and the consequent decrease in appetite. Sources of soluble fiber are: inulin, chicory, radicchio, bruxel sprouts, avocado, broccoli, flax seeds and hazelnuts.

6. Anxiety or irritability

Initially, similar to point 5, since your body is not used to use ketones as energy, this could cause anxiety or irritability.

These side effects can also be attributed to a lack of potassium or vitamin B1 which are natural relaxants.

How to fix this? Increasing your consumption of foods with potassium and vitamin B1 should manage the problem. Specifically, a large salad of leafy green vegetables and with the addition of nutritional yeast would manage potassium and vitamin B1 in one go.

7. Tachycardia

Dehydration, as seen in point 1, is a side effect of the ketogenic diet that causes loss of electrolytes, such as potassium, magnesium and sodium. Electrolytes are very important for the functioning of the heart and a deficiency in them could cause tachycardia and palpitations.

How to solve the problem? As with many other points seen previously you will have noticed many things in common, such as the consumption of vegetables, and even here vegetables will be your best ally to increase the intake of minerals and electrolytes. Plus an avocado will also give you a great supply of potassium and magnesium.

For more information read the article: 7 segnali che si è in uno stato di chetosi.

Long-term side effects

The side effects in the long term are closely related to the type of ketogenic diet used, which is often confused as a diet characterized by high consumption of proteins and fats.

While it is true that the ketogenic diet involves the consumption of a lot of fats these should usually be the fats that come with food. Many add a lot of extra fats such as butter, coconut oil, MCT oil.

Furthermore, the consumption of proteins such as eggs, pork or beef often occurs in excess. In fact, many people probably aren't even ketosis due to too much protein.

8. Kidney stones

In the long run, the ketogenic diet could cause kidney stones. In fact, this type of diet causes an increase in uric acid in the urine. This effect usually depends on an excessive consumption of proteins (remember that the ketogenic diet should have a moderate consumption of proteins) and the predisposition of the individual to the formation of stones.

How to fix it? First of all, if your protein intake is excessive you will need to cut it down now. Gender recommends the size of the palm of your hand as the volume of protein per meal. Also if you eat more than 2 meals a day, it is advisable to adopt a regimen of intermittent fasting.

Other useful tips are: drink plenty of water, consume citrates (lemons and limes), reduce foods with high levels of oxalates (almonds, spinach, chocolate).

For more details read the following article: 6 ways to prevent stones in the ketogenic diet.

9. Increase in blood cholesterol

In the long run, a high-fat diet is likely to cause an increase in blood cholesterol. However, it should be noted that there are 2 types of LDL particles (the so-called bad cholesterol): a large one that does not cause damage to the arteries, and a smaller one, which is the real bad LDL particle.

In the case of the ketogenic diet, usually the first LDL variant is the most frequent, which should not cause problems with the arteries.

However, it should be noted that there are quite rare cases where the person is unable to metabolize fats well. Some genetic factors could also cause an increase in triglycerides (for example in the case of those suffering from sitosterolemia).

How to solve the problem? In the rare case of sitosterolemia it would be better to eat more fats derived from animal rather than vegetable sources (obviously it is good to consult your doctor before making changes to the diet).

In the case of an increase in triglycerides it could be caused by this new phenomenon of lean mass hyper-responders, i.e. thin people who respond with a significant increase in LDL with the ketogenic diet.

In this case, increasing the daily amount of carbohydrates seems to help lower the LDL level.

For more information on the ketogenic diet and cholesterol read the following article: Ketogenic diet and cholesterol.

Conclusions

The ketogenic diet is very effective in weight loss, but it may cause unwanted and unpleasant effects.

Several side effects, as we have seen, can be regulated by an increased consumption of low-carb vegetables and fruits such as avocado.

In conclusion we can say that most of the undesirable effects can be solved in a simple way and that overall the ketogenic diet can be considered safe in most cases.