In a world heavily focused on diet culture and a desire to alter our bodies, the Keto (short for Ketogenic) diet has become a household term. If you haven’t heard of it, the keto diet is similar to other well-known diets aimed at helping people lose weight, such as Paleo, Atkins, and Whole30. These diets are similar in that they recommend restricting the intake of certain food groups and increasing the intake of other food groups.

The Keto diet, specifically, aims at limiting carbohydrates as much as possible (aiming for 20-50g per day), and increasing fat intake to account for ~90% of total daily calories. Why, you might wonder?

The body’s primary source of energy comes from eating carbohydrates (fruits, vegetables, grains, etc.). Carbohydrates are made up of chains of glucose (or sugar) that are easily broken down and used by the body. Because of the easy breakdown, it provides a quick source of energy to our body and fuel for our brain to use immediately.

The human body is smart and, for the most part, self-regulating. When our body doesn’t receive enough energy from food, specifically carbohydrates, the body goes into fight or flight mode and takes it upon itself to create energy in other ways. One way is by breaking down our stored form of energy from carbohydrates, called glucose and glycogen. Once the body has used all its stored carbohydrates, it starts breaking down fat and converting that into energy. When the body breaks down fat, it creates “ketone bodies” which are the usable form of fat energy (just like glucose is the usable energy from carbohydrates) If we could use our fat sources as a source of energy, that means we are burning fat and losing weight, right?

Technically speaking, yes. However, it takes many days of an extremely low carbohydrate diet for the body to enter a state of ketosis (the state that the body is in when it uses ONLY fat for energy). It is important to keep in mind that the body only enters this state of ketosis once all the body’s carbohydrate sources are used up. While the body adapts to this unnatural use of energy, many people report feeling sick both mentally and physically, which has been referred to as the “keto flu”. The brain and body need energy from carbohydrates to function, so depriving the body of this necessary nutrient causes weakness, mental fog, headaches, and other flu-like symptoms.

Many people believe that they are following the keto diet when they eat a diet low in carbohydrates and high in fat. As mentioned above, the body needs to fully transition to using fat as energy for the body to be in a state of ketosis. People following this diet are advised to check the level of ketones in their bodies by using a urine strip. People who follow a low-carb, high-fat diet but who are not able to put their bodies into ketosis are not burning the excess fat that they are eating. Anyone who attempts to follow this type of diet, but especially those not in ketosis, is at an elevated risk for many health complications mentioned below because a high-fat diet poses many risks to the body, specifically the heart.

1. Heart disease– A high-fat diet includes the intake of fats that may not be the healthiest for the heart, including saturated fat. The keto diet may increase the risk of heart disease by raising “bad” LDL cholesterol.
2. Nutrient deficiencies due to reduced intake of fruits, vegetables, and whole grains
3. Liver problems due to excess work on the liver to metabolize high volumes of fat.
4. Constipation due to low intake of high-fiber foods (fruits, vegetables, and whole grains)
5. Mood swings and brain fog due to deprivation of the brain’s preferred energy source, carbs.
6. Disordered eating- those who follow restrictive diets are at an increased risk for developing eating disorders.

You might be wondering why the keto diet exists if it has this many health consequences.

The Keto diet was developed by Dr. Russell Wilder at the Mayo Clinic in 1924 as a treatment for epilepsy, prior to the development of anticonvulsant medications. Epilepsy is a brain condition that causes seizures.

Today, the keto diet is prescribed mostly to children who don’t respond to seizure medications. Research has shown that the keto diet reduces the number of seizures in 50% of children with epilepsy and has even been shown to stop seizures completely in ~15% of children with epilepsy.

The keto diet gained popularity as a weight loss diet in recent years with the rise of diet culture. Diet culture causes individuals to become hyper-focused on healthy foods and the need for our bodies to look a certain way. Individuals who started using the keto diet as a means of weight loss thought that if we were limiting our carbohydrate intake and using fat as our main source of energy, we would lose fat, and therefore weight. Monitoring intake in this way is actually not a sustainable, long-term method of eating or weight control.

The keto diet is a useful diet for those with certain health conditions and is generally not safe for the broader population. The best and healthiest way to eat is to follow a balanced diet high in fruits, vegetables, whole grains, lean meats and fish, but all foods are healthy to consume in moderation.

Remember, it is always important to do thorough research on a diet you may be interested in trying and you should always ask your healthcare provider if a certain diet is right for you.