Despite research showing that anywhere from 95-99% of diets do not work, we still hear about them everywhere. One of these that has gained a lot of popularity recently is the ketogenic, or keto, diet. Because we always hear about it from a diet culture perspective, let’s delve into what it is without the BS – no weight stigma or diet culture. Keep in mind that research has shown that the majority of diets do not work and yet they are still “shown” to work. As such, I want you to have all of the (unbiased and scientifically accurate) facts about what this diet entails, what its history is, and all of the side effects that anyone trying to sell it to you will conveniently not mention.
The classic ketogenic diet is a high fat and low carb diet, meaning that anywhere from 75-90% of an individual’s calories in a day would come from fat (exact percentages vary between different sources). This diet is designed to force your body to use fat as its main source of fuel as opposed to its normal source of fuel (carbohydrates). When your body does this, it goes into a state called ketosis. During ketosis, there are high levels of what are called ketones, or ketone bodies, present in the blood and urine. This state can take a few days to get into.
This diet was designed specifically for adults and children with epilepsy. (However, there has recently even been caution that the classic form of the keto diet should not be used in adults because of how restrictive it is.) Epilepsy is the fourth most common neurological disorder and is characterized by unpredictable seizures (the types and control can vary from person to person). It was introduced by doctors in the 1920s as a treatment for epilepsy because it mimics the metabolism of fasting and was used as the main epilepsy treatment up until the late 1930s when anti-epileptic drugs were introduced.
While the introduction of anti-epileptic drugs was beneficial in many ways, it also resulted in less and less dietitians being properly trained in how to use, administer, and monitor the keto diet. This is so important because recent research has allowed us to see that this is not a diet that should just be tried on a whim by any random person. While this might seem obvious given that it’s a diet designed for people who suffer from a seizure disorder, it is quite important to mention given how popular it has become in recent years among the general public.
This is not to say that there is no merit to the keto diet – if you are suffering from epilepsy. According to the National Epilepsy Foundation, over half of children with seizures who are on the keto diet see at least a 50% reduction in the number of their seizures. However, the merit of this diet stops right around there. As mentioned earlier, it is cautioned against using in adults because of how restrictive (and thus not sustainable or realistic) it is, and, according to a study entitled History of the Ketogentic Diet, it is a next to last or last choice for treatment of almost all childhood epilepsies.
While the ketogenic diet is sometimes seen as a quick-fix for people who suffer from epilepsy, it is not recommended for people who do not have the disorder because there is very little evidence to prove that this is effective or safe in the long run for anything besides epilepsy.
However, there have been studies done on people who have been on the keto diet for a few years and have produced some key insights into the side effects. These include kidney stones, constipation, slowed growth, nutrient deficiency, low blood pressure, increased risk of heart disease, fuzzy thinking, hepatic steatosis (fatty liver), and more. This is obviously a lot, but when you break each effect down it begins to make sense.
Nutrient deficiency is perhaps the most obvious of the side effects. When you’re eating hardly any carbohydrates, this means your diet is lacking important foods like fruits, vegetables, and grains. You are also at risk for deficiencies in micronutrients like selenium, magnesium, phosphorus, vitamin B, and vitamin C. Your brain especially needs carbohydrates to function properly (glucose is your brain’s primary source of fuel) and therefore helps to explain the side effect of not being able to think clearly. Your brain alone uses about 20-30% of the energy that you consume in a day!
The side effect of heart disease can be at least partly explained by the increase in “bad” or LDL cholesterol that is associated with this diet. Another (relatively common) side effect of the keto diet is what is referred to as the “keto flu”. This term represents a group of symptoms that tend to occur during the first few weeks of someone partaking in the keto diet. These symptoms include an upset stomach, dizziness, mood swings, and low energy. Limiting your diet so severely can also cause disordered eating and/or social isolation. Dieting in general is a risk factor for eating disorders particularly in those who already are experiencing other risk factors and/or have some sort of genetic predisposition.
All in all, staying on the keto diet can cause a myriad of health concerns, both physically and mentally. So, if you are going to try the ketogenic diet, it should be carried out with the care and guidance of a licensed dietician. Always do your own research and consider your own body’s needs rather than just going along with what an advertisement on TV or what a post on social media tells you will solve all your problems!
Burkitt, M. J. (2020). An overlooked danger go the ketogenic diets: Making the case that ketone bodies induce vascular damage by the same mechanisms as glucose. Nutrition, 75-76. https://doi.org/10.1016/j.nut.2020.110763
O’Neill, B. & Raggi, P. (2019). The ketogenic diet: Pros and cons. Atherosclerosis, 292, 119-126. https://doi.org/10.1016/j.atherosclerosis.2019.11.021
Wheless, J. (2008). History of the ketogenic diet. Special Issue: Ketogenic Diet and Related Dietary Treatment, 49(s8), 3-5. https://doi.org/10.1111/j.1528-1167.2008.01821.x