In the world of fitness and weight-loss, the ketogenic diet is the new kid on the block. Rumour has it, it’s key to optimizing fat-loss, strength and curbing our appetite. But how much of this is true? Or could this high-fat, low-carb diet be just another trend? The good news is – you’re about to find out.
First things first: What is a ketogenic diet?
A ketogenic diet means that you get approximately 75% of your daily energy from (healthy) fats, 20% from protein and only 5% from carbohydrates (mainly vegetables) – which basically means only between 30g-50g of carbs per day. (This would translate into one single cup of rice or two slices of whole wheat bread per day).
What does “ketogenic” mean?
This one’s for all the geeks out there: Ketogenic comes from the word “Ketosis”, the name of a metabolic process your body goes through to produce enough energy to keep the engine running. It happens when we don’t have enough glucose from carbohydrates for energy production and our body then has to use fats to generate energy – also known as beta-oxidation. We do this on a daily basis, for example when we sleep. In this process, fatty acids are broken down into acetyl-CoA, which is an essential molecule in energy transfer. Nevertheless, if the body has mainly only fats for energy production, it will come to a metabolic traffic jam, as not all acetyl-CoA can be used for energy production. Acetyl-CoA builds up. And this build up of acetyl-CoA shifts the liver into ketone body formation. And here we are: if the body has more ketone bodies than normal, it is in “ketosis”. These ketone bodies – acetone, acetoacetate and beta-hydroxybutyrate – can be reconverted into acetyl-CoA when energy is required to help supply the muscle tissue, the brain and red blood cells. Making ketone bodies is not how our body prefers to get it’s energy, but it’s a brilliant back-up system when glucose is low.
Can a ketogenic diet boost my brain function?
Maybe. Obviously, there are individuals who have experienced this, otherwise there wouldn’t be so many nonfiction books out there1. Some people reported a cognitive boost after being on a ketogenic diet. Nevertheless, concrete research on the cognitive effects of ketosis in healthy people is still lacking. The underlying biochemical processes which could be responsible for brain function enhancement are complex. In simplified terms: a ketogenic diet might improve the function of our mitochondria – the power generators of our cells. This would contribute to a higher energy production. Furthermore, a ketogenic diet – if done properly – is high in omega-3 fatty acids. The importance of healthy omega 3 fatty acids for proper brain functioning have already been scientifically proven2.
Can a ketogenic diet boost my athletic performance?
Most likely not. Yes, there are metabolic adaptations, which may sound really appealing. For example: by using ketone bodies as fuel, you increase fat oxidation, spare glycogen and produce less lactate. BUT – the opinion of the majority of exercise physiologists is that you are not going to go as fast as you can when using ketone bodies instead of glucose. Especially with High Intensity Interval Training (HIIT). Again, clear evidence is still lacking.
Can a ketogenic diet contribute to my weight-loss?
A ketogenic diet is not the magical solution for weight-loss. If you eventually want to lose weight, you must be in a caloric deficit. Period. Studies have shown, that in the long-term (after a year) it didn’t matter if people were on a low-carb, low-fat or low-blabla diet3.
Only in the short-term can a low-carb diet induce greater weight loss (i.a. through a higher appetite suppressing effect). Nevertheless, what really makes the difference is consistency. This means, you will only lose weight if you burn more calories than you consume over a long period of time. You must develop a healthy lifestyle in the long run, which means a healthy diet in combination with regular exercise.
Can ketosis be dangerous?
You have to be aware that ketosis can become dangerous when too many ketones build up. We call this situation “ketoacidosis”, which is a potentially dangerous metabolic situation of uncontrolled ketosis. However, this usually only happens in alcoholics and diabetics, where the self-regulatory mechanisms doesn’t work properly. Nevertheless, you should talk to your doctor before considering a ketogenic diet.
A ketogenic diet is one of the most restrictive diets, because it drastically limits your food choices and this restriction is almost impossible for most people to apply to their everyday lives, especially in the long-term. When it comes to disadvantages, there are some short-term (electrolyte depletion, headache, fatigue, nausea etc.) and long-term disadvantages (elevated blood lipids, lower bone density etc.) people endure when following the ketogenic diet.
However, others experience improvements, for example a boost in cognitive function. Nevertheless, more significant human studies must be conducted to support these findings.
Now to answer your real question: should I try it?
If you are a normal person who just wants to be healthy and fit, you can of course try it (after asking your doctor). But you should always remember that you can be perfectly fit, lean and healthy without it. And if you feel as though it doesn’t agree with you, or that you are putting your body under a substantial amount of stress, reconsider if it’s right for you.
Lastly, don’t believe everything you read on the internet. Ketosis is not the cure for everything. If you want to feel good, look good and take on a more athletic lifestyle, it’s all about finding a healthy balance that you will stick with.