The keto diet, also known as the ketogenic diet, has been growing in popularity in recent years. It’s essentially a Low Carb High Fat diet (or LCHF diet). The name says it all: eat tiny amounts of carbs and more or less unlimited amounts of fat. Its appeal lies in the fact that you can lose weight while feasting at an all-you-can-eat bacon buffet. But what many don’t know is that it wasn’t designed as a diet to help people lose weight. At its core, this is a method to keep childhood epilepsy under control.

Keto and epilepsy

Let’s travel back in time to the 1920s. Children with epilepsy had the option of treating their condition with medications, but a number of children did not respond well to any of the available medications. Doctors were trying to help those children and found a way by using centuries-old fasting methods. They developed the keto diet which mimics the metabolic processes present during fasting periods. This proved to be very successful and it turned into the go-to method for children struggling with epilepsy. But why does it work?

When you eat carbs, they go through your digestive system and turn into glucose, the main energy source for your brain. Take away the carbs and your brain has to find a different energy source. This is where your liver comes in. With only a tiny amount of carbs available, your liver starts to turn stored fat into fatty acids and ketone bodies. The ketone bodies replace glucose as the energy source for your brain.

The increased level of ketone bodies in your blood is called ketosis. It enhances the synthesis of GABA (Gamma-Aminobutyric Acid), a neurotransmitter that reduces chemical messages to nerve cells, and this is what makes it less likely for a seizure to occur. About half of children with epilepsy report a 50% reduction in epileptic seizures when on the keto diet. These are amazing results for anyone who doesn’t respond well to medications.

Over the years as more medications became available, the keto diet lost some of its appeal. Fast forward a few decades and it received a sudden boost in popularity, only for a different reason: weight loss.

Why does keto work as a weight loss method?

Let’s return to our good friend glucose. Your brain needs it. If there is no glucose, the brain will get its replacement energy from fats. Because your brain’s favourite food is glucose, it will not accept fats as long as carbs are available. This is why people on a keto diet need to consume close to no carbs (less than 10% of daily calories should come from carbs) and about 70-80% of calories need to come from fats. So instead of getting glucose from foods like grains, legumes, fruit and vegetables, it gets ketone bodies from stored fats. Sounds like the perfect weight loss method! But is it really?

For your body to produce ketone bodies, you can eat 20-30 grams (about an ounce) of carbs per day. For comparison, a medium banana has 27 grams of carbs so that’s your quota for the day pretty much filled. It takes a few days of this low-carb regime for your body to enter ketosis and that’s when it starts producing ketone bodies. The problem is that eating too much protein can also affect ketosis so there is only one solution: fill your plate with fat at every meal.

Because you can’t eat a lot of protein, your fat source will inevitably end up being fatty meats like pork, especially bacon. These are saturated fats, known to cause all kinds of health problems. Of course, you are welcome to eat your avocado, salmon, nuts and seeds, but those will not be enough to get you to the 10% carbs – 20% protein – 70% fat ratio. By now you can probably see how this diet ends up being problematic for those who only follow it for weight loss.

Wait, what about vegetables?

You may be tempted to say keto can be a healthy way to lose weight because you can eat vegetables with your fatty meat. Well, not exactly. You are welcome to eat vegetables, but vegetables contain carbs too so you have to keep an eye on your numbers. You can only eat a certain amount of vegetables every day so you don’t exceed your daily carbs limit. Leafy greens are your best bet, everything else will get you to the 30-gram limit very quickly. And yes, you are technically allowed fruit, but fruit is so full of carbs you will reach your daily limit by the time you finish breakfast.

Risks of a keto diet

Keto has been extensively studied as a method to help with epilepsy. For anyone who experiences epileptic seizures and can’t count on medications to help this is a great diet because all the benefits outweigh the risks. For anyone who doesn’t have a medical reason to follow the keto diet plan the risks are most likely not worth it. But you can judge for yourself.

Keto diet risks include:

• high cholesterol: Consuming large amounts of saturated fat increases your LDL cholesterol and therefore increases your risk of cardiovascular diseases.
• nutrient deficiencies: Removing entire food categories from your diet is problematic, especially when you’re removing legumes, fruits and grains which contain a lot of vitamins, minerals and fibre.
• liver problems: While on a keto diet, your liver has to process a lot more fat than it normally would, which can cause problems and complications.
• kidney problems: While on a keto diet, your kidneys have to process more protein than normal, which can cause issues such as kidney stones.
• constipation: Cutting legumes and grains from your diet means low amounts of fibre are consumed and this is likely going to cause constipation in most people.
• mood swings and brain fog: Like it or not, our brain needs glucose to function properly. Low carbs = low glucose = slow brain.

These risks can have serious consequences for your health, especially long term. If you have no medical reason (such as epilepsy) to follow the keto diet, make sure you discuss it with your doctor before you start as you may do more harm than good.

So who should follow the keto diet?

Keto can be extremely beneficial for children who can’t use medications to help with their epilepsy. Despite the risks, all the benefits are still worth it when you no longer have to deal with epileptic seizures on a daily basis.

You may want to consider going keto if you are extremely overweight, to the point where you risk cardiovascular and similar issues anyway. In that case, the fast weight loss that keto can provide could be worth it.

Anyone who has problems with their liver, kidneys or cholesterol levels, don’t do it, keto will do more harm than good. If you are pregnant or breastfeeding, don’t do it, it’s far too risky. For everyone else who is only looking to lose the 10 or 20 kg they have extra? It’s highly likely not worth it so try to find a different method that won’t harm your health like keto does.