This objection from a dietitian (Dietitians Weigh in on the Low Carb/Ketogenic Diet) actually has some truth in it but in the most serious charge is way off base. Here’s the objection as it was written:
…comes with some a slew of risks. These risks can start with symptoms such as headaches, fatigue, fogginess and if left untreated, possible coma and death. There biggest risk is diabetic ketoacidosis which is the result of too many ketones in the blood, a lack of insulin and blood glucose spiking too high. Left untreated, diabetic ketoacidosis can be potentially fatal.
Keto Flu Symptoms
It is true that the diet has various symptoms during the withdrawal from carbs. The symptoms of keto flu are “headaches, fatigue, fogginess” and they can last a couple of days to as much as a week. And they cause many people to tap out. That’s why it is important to help people understand and treat these symptoms.
These symptoms are similar to the withdrawals from any addictive substance. Sugar is no different. That could cause some who is going through them to ask the question why when they stop eating carbs that they go through the symptoms of heroin withdrawal (albeit in a smaller way)?
If carbs are so good then why am I going through these sorts of symptoms? The first reason comes from the switching of fuel sources from glucose (which drops quickly) to ketones which take a few days to kick in.
This can be seen in studies of starvation. The curve on the left is the blood glucose which falls in the first few days and then levels out. The fact is well all feel worse as our blood sugars drop. That is a normal condition. I felt best when my blood sugar was around 300 (normal is around 85) and unless you are testing your blood sugar you don’t know that you are still just fine.
Around day 2, the ketone bodies start to kick. They are your new fuel and it will take a few days for them to reach sufficient levels to meet your needs.
The reason people feel bad when going into keto is that their body was normally accustomed to being fueled by glycogen and that fuel source is limited.
Along with the drop in glycogen comes a very large drop in water weight. For every gram of glycogen your body stores 3-4 grams of water. Along with this water loss comes a loss of electrolytes.
For me cramps in my legs (calves in particular) as I was falling asleep. This was my signal that I needed to have more magnesium, potassium and sodium.
This is very easy to treat. For most people just eating a small amount of salt will bring immediate relief. For others more electrolyte supplementation may be required. See this for more information (Electrolytes, Water Retention, Low Carb Diets).
This is a rare condition which is not a by-product of the ketogenic diet. Quite the contrary since it is a risk of untreated diabetes. And yes, it is often fatal. I have a personal friend who died from this. It is typically found in someone who is an undiagnosed diabetic.
It is accompanied by very high blood sugars. Remember what happens when you start a ketogenic diet (see above)? Your blood sugar drops. That is why diabetic ketoacidosis is describing a completely different condition. In the untreated diabetic both ketones and high blood sugar are present. In the ketogenic diet ketone levels don’t reach these deadly levels so both conditions for DKA are not present.
The diabetic who doesn’t do a ketogenic diet has a much higher chance of dying from DKA than a diabetic on the ketogenic diet. Again, just comparing the risks shows the dietitian’s claim is false.