The Keto diet works by forcing your body to switch energy source glucose to ketones, which is a metabolic state, called ketosis. You can do that by cutting your carbs intake and increasing fat intake.
The biggest problem to follow a keto diet is that you have to restrict all of your favorite carbs and you will have limited eating options than your regular diet.
This why for many people this diet seems almost impossible to follow for a long time. Sustantilibly of the keto diet is very low.
1. Keto flu
This will be the first side effect of a keto diet, you may experience.
But keto flu appears in the first or second week of starting a diet and it is generally manageable and goes away within a few days.
Most people will experience this when they start a keto diet.
Keto flu appears when your body tries to adapt to low carbs state. In other words, the body changes its one metabolic state to another metabolic state called ketosis.
Lowering the carbs intake will force your body to burn fat and use ketones for energy. At that time you may feel symptoms collectively referred to as keto-flu.
These symptoms will again reappear when you try to quit keto. These symptoms appear when the body tries to adjust itself for a new source of energy.
Symptoms of keto-flu you may experience
- Stomach pain
- Bad breath
- Muscle soreness
- Loss of electrolyte
- Frequent urination
You can minimize these effects by drinking plenty of water, and taking good night’s sleep. You can drink green tea, organic coffee and taking nutritional supplements, etc., which can reduce these symptoms discomfort significantly. 
Fatigue and lethargy, you experience are generally the cause of your brain is not getting enough energy.
Glycogen depletion and oxidative stress is the main cause of exercise-induced fatigue. 
This side effect is not that severe but still, it can make you uncomfortable. But once you are in complete ketosis this side effect will go away.
You will frequently visit the bathroom while you are on the keto diet and believe me most people do.
Diarrhea can be due to a lack of fiber in your diet. When you cut carbs like whole grain, bread, etc., and do not get enough fiber through your diet or supplement can cause diarrhea.
If you are eating too many dairy products and artificial sweeteners can also cause diarrhea.
- Eat fiber-rich foods such as vegetables like broccoli, cauliflower, Brussels sprouts, cabbage, kale, Celery, Zucchini
- Eat fewer dairy products and artificial sweeteners.
4. Muscle loss
You can lose muscle in the keto diet, even if you are doing resistance training. However, very small studies are available.
This can be due to that protein alone may not be that effective as it can be with carbs.
A study suggests that following a keto diet with engaging with weight lifting, running or aerobics exercising can reduce the leg muscle mass  
However, more research needed to long term keto diet effect.
If you are aged loss of leg muscle mass can have several serious consequences. 
Eat more protein-rich foods such as Spinach. Asparagus, Mustard greens, Broccoli, Avocado, chia seeds, Asparagus, etc.
5. Kidney stones and heart rhythm problem
Increased urination can lead to loss of electrolytes such as sodium, potassium, and magnesium. This can increase your chances of injuring the kidneys.
Dehydration is a serious problem in the keto diet can cause kidney stones.
Electrolytes are necessary for normal heart rhythm. So the loss of electrolytes can cause irregular heart rhythm.
- You should eat avocado, citrous vegetables, leafy greens asparagus, which are a great source of electrolytes.
- You can take supplements from a certified nutritionist.
6. Reduce performance
A recent study shows that a Ketogenic diet can reduce athletic performance.
Researchers found that participants performed worse on high-intensity cycling after four days on a ketogenic diet as compared to those who were on a regular high carbs diet. 
This may be due to the acidic state. Your body is in a more acidic state When you are in ketosis and that can limit your body to perform at peak level.
If you have Diabetes Mellitus, then you should always follow the keto diet after concerning your doctor and under supervision.
Ketosis can be helpful for people with hypergymnasia because it decreases the blood sugar level, but you should check the glucose level several times a day. 
the keto diet can cause an episode of hypoglycemia in people with type 1 diabetes, which is a dangerous condition. 
Because in people with diabetes, ketosis can trigger ketoacidosis.
When your body stores too many ketones – acid is produced as a product of burning fat and blood become too acidic that can damage kidneys, brain, liver, etc.
Symptoms of ketoacidosis
- Dry mouth
- Bad breath
- Frequent urination
- Breathing difficulties
8. Yo-yo dieting
When you go on a keto diet, you will lose lots of weight very fast. Due to the depletion of fat stores and water loss.
But the problem is that most people gain lots of weight when they go back on carbs. It is a common issue with this diet.
You will lose weight very fast, but also regain most of the lost weight.  It can be worse if your diet habit is unhealthy.
There are very limited studies on a long term keto diet because it is difficult to follow for a long time. So there are high chances that you will also quit the keto diet too and regain your weight. 
This back a fourth fluctuation is also called yo-yo dieting and can have potential risks on your health.
9. Nutritional deficiency
The Keto diet is low in fruits, vegetables, legumes, and whole grains that are generally considered healthy and full of fiber and nutrition.
Without this food, you can easily miss certain vitamins, fiber, phytochemicals, and minerals. 
This can cause bone loss and increased the risk of some chronic diseases in the long term.
The ketogenic diet is not a great diet for the long term because there is not a balance between carbs, protein, and fat.
Keto diet can be used for fat loss in the short term, for the long term under the supervision of a doctor.
- Ask advice from the doctor
- You can take supplements of nutrient which you are missing
- Redesign your diet plan.
The Keto diet eliminates most of the fruits, vegetables, and legumes which are a great source of fiber.
In this diet, you can easily miss fiber which can cause difficulty in bowel movement and constipation.
- Eat fiber-rich keto-friendly foods such as cabbage, broccoli, asparagus, etc.
11. Bad breaths
Keto diet can cause bad breath, it is not necessarily dangerous. When your body in ketosis, the liver metabolizes fat and changes it to ketones which will circulate in your body to give energy and diffuse in the lung. Bad breaths can be a good indicator that you are in complete ketosis. 
To maintain a balance of ketones, the body exhales the ketones and can cause bad breath acetones like smell.
- Drink plenty of water
- You can take gum or sugar-free mint to control the current situation.
12. Decreased in sodium
Your body can easily lose sodium and other electrolytes in the urine because keto reduces the insulin that stores it. So it is necessary to add sodium to your diet.
Low levels of sodium can cause leathery, leg cramps, vomiting, etc.
13. Weaken your immune system
It is found that a keto diet can disrupt the balance between good and bad bacteria in the gastrointestinal tract. The lack of probiotics can decrease the friendly bacteria in the gastrointestinal tract. And this will impact your immune function.
Is the keto diet good for you?
Keto diet is not good for everyone, especially if you have diabetes, high blood pressure. If you have these conditions, other medical conditions or you are on medication you should talk to your doctor before considering the keto diet.
Keto diet can changes, metabolic and many other processes of your body, this can change the effectiveness of the medication of the person.
Patients should be closely monitored by a physician because patients may need supplementation, changes in medication dosage, etc.
If you have a blood pressure issue you might need sodium and potassium supplementation.
The Keto diet is not a balanced diet so it can easily cause micronutrient deficiencies in the long term. And you might need several supplements.
Keto diet can help you to lose weight very fast, but as long as you are doing safely.
If you are on a keto diet and experiencing any of those side effects. And you will.
Then you should concern, your doctor or your health provider and start taking a supplement. It is necessary to make the nutritious balance in your body no matter you are on keto or another diet.
In a long-term keto diet, you can easily miss many essential nutrients. This deficiency can cause a serious problems and chronic diseases such as diabetes, heart disease, and many others.it would be a great idea to design your diet before starting a keto diet.
If you have diabetes, you should concern your medical provider before doing starting a keto diet.
Before starting a keto diet you should ask yourself that is losing weight fast can cancel out these potential side effects on your health.[showhide type=”links” more_text=”(+)Source” less_text=”(-) Source”]
- Health.com “7 Dangers of Going Keto” “https://www.health.com/weight-loss/enlightened-ice-cream-keto”
- Healthline “Here Are the Worst Side Effects of the Keto Diet” “https://www.healthline.com/health-news/worst-side-effects-of-the-keto-diet#1”
- GH “The 11 Biggest Keto Diet Dangers You Need to Know About” “https://www.goodhousekeeping.com/health/diet-nutrition/a25657033/keto-diet-dangers/”
- NCBI “The glycaemic benefits of a very-low-carbohydrate ketogenic diet in adults with Type 1 diabetes mellitus may be opposed by increased hypoglycemia risk and dyslipidaemia.” “https://www.ncbi.nlm.nih.gov/pubmed/29737587”