Over the last few years, I have seen and been asked as a dietitian by so many people how I feel about the ketogenic or “keto” diet. It’s become a huge craze on tiktok, instagram, and all over social media. Due to this, I think that providing a comprehensive and scientific look into this diet is extremely important. Not only will it help to debunk or demystify some of the claims of this diet, but it also will hopefully help to clarify any misinformation that has been presented to the public throughout social media.
Let’s get into it!
What is the Keto Diet?
If you haven’t heard of the keto diet, here’s a brief introduction. The keto diet was originally created due to its evidence in reducing severe childhood epilepsy and seizures back in the 1920s. Although it was created specifically for these medical reasons, society has taken it and turned it into a fad diet and weight loss tool. The ketogenic diet is a diet that is extremely high in fat (65-75% of your diet), super low in carbohydrates (<5% of your diet) and moderate in protein (15-20% of your diet). For reference, the Office of Disease Prevention and Health Promotion sets the acceptable macronutrient distribution ranges as 45-65% of your daily intake from carbs, 20-35% from fats, and 10-35% from protein. Yikes! In order to obtain this level of high fat intake, the ketogenic diet calls for a high intake of foods such as meat, fish, butter, eggs, cheese, heavy cream, oils, nuts, avocados, seeds, and low carb veggies. Sadly, this also means cutting out important carbohydrate sources such as rice, beans, potatoes, cereals, fruits, grains, etc. Not only is this cutting out important nutrients, entire food groups, etc. it is also encouraging a highly restrictive mentality with food that is the complete opposite of food freedom and intuitive eating.
What is Ketosis?
If you know anyone who has been on or is on the keto diet, you would have likely heard the word “ketosis” being thrown around. However, what does that actually mean? First and foremost, ketosis is not an optimal thing. Many people on the keto diet will use that term as something that they are hoping to achieve, knowing that it has something to do with fat being used as energy. Let’s look into this a little more.
Our bodies function most optimally on glucose (carbs). In fact, it is our body and brain’s favorite form of energy as it allows us to function at our best and function as we need on a daily basis. Now, when our body is not getting enough glucose (either when we are cutting our carb intake i.e. the keto diet and many other restrictive diets or not eating over an extended period of time), our body goes into survival mode. It begins looking for other energy sources to take over the role that carbs play in the body. However, without carbs, insulin levels in the body drop and fat is released from the cells. Once this happens, that fat is taken to the liver where it becomes overwhelmed and turns into ketones. These ketones are then used as a secondary source of energy for the body.
Your body functions best on glucose as mentioned before, in fact that is what it wants and strives for. Although our bodies can function without carbs, it does not want to. Carbs are still our brain's favorite source of energy and some cells in the brain actually can only run solely on glucose.
Ketoacidosis in Diabetes
Let’s break down the difference between ketosis and ketoacidosis as I’ve seen some confusion on the difference between the two. Ketoacidosis occurs in those individuals with type 1 diabetes. When those individuals lack insulin in their bodies or are not eating enough carbohydrates, their bodies enter a state known as ketoacidosis. This includes an increased level of ketones in the blood leading to an increased acidity in the blood. This increase in acidity can lead to coma or in some cases death. The difference between these two is incredibly important. Bottom line: ketosis and ketoacidosis are different mechanisms and although ketosis is generally safe for a healthy individual, it is still not optimal for the body and its mechanisms.
Let’s look at the potential health risks of the keto diet
One of the more recent health risks associated with the keto diet and other low carbohydrate diets is its impact on pregnant individuals. In fact, a study conducted in 2018 found that pregnant individuals who were restricting their carbohydrate intake were at more increased risk for their babies developing neural tube defects. This was in fact in conjunction to taking a folic acid supplement which is primarily prescribed for preventing this complication.
The ketogenic diet cuts out whole fuel groups and thus means that individuals on this diet are missing out on important vitamins and minerals. Some of the major minerals missing in this diet include sodium, potassium, and chloride. Other vitamins missing from this diet include vitamin D, calcium, magnesium, selenium, and zinc. With this decreased intake of vitamin D and magnesium, it has been found that there is an increased risk for reduced bone health and risk of long term bone disease and risk of fractures.
With the increased fat intake of the keto diet, of course we are going to be concerned about impacts on cholesterol levels. A study published in 2020 found that a keto diet can rapidly increase total levels of cholesterol, including low-density lipoproteins (ie “bad” cholesterol). This increase can be potentially dangerous for those at risk for cardiovascular disease. These results suggest that overtime, the keto diet may potentially lead to an increased risk of hypercholesterolemia and hypertriglyceridemia.
Constipation is one of the more common side effects of the keto diet. Since the diet is incredibly low in fiber rich foods such as fruits, grains, and certain veggies, it leads to increased susceptibility to constipation. In fact, as many as 75% of those who tried the keto diet experienced some form of adverse GI symptoms.
Bottom line: our bodies need all fuel groups to function at their best. By cutting out certain fuel groups like carbohydrates, our bodies are missing out on important and essential nutrition that it craves to function optimally. Although the keto diet may seem like a quick fix for weight loss, it comes with a whole boatload of possible side effects and long term effects. Not only that, the keto diet like other restrictive diets keeps you in a cycle of diet culture that is completely opposite of food freedom! Hopefully this blog post helped to clarify some myths around the keto diet and if anything, give you a better view into why you should definitely not try it!