Keto Vs Low Carb – What’s The Difference?
The low-carb diet has long been symbolic of weight loss. The ketogenic diet is currently all the rage. Many people are transforming their lives and minds by eating keto and likewise many are sceptical about whether it’s healthy long-term. What’s the difference between keto and low-carb diets?
What Is The Low Carb Diet?
It’s important to recognise that “low-carb” is a general term. But there are some generalisations about low-carb diets which most people agree with.
A low-carb diet tends to be low in carbohydrates (duh) but also high in protein, with moderate-high fat consumption. Again, there’s no dictionary definition for each macronutrient, but this is what I have observed over the years.
Cereals, bread, pasta and even fruit are usually substituted with meat, dairy and vegetables.
Low-carb diets have always been known for their “magical” properties when it comes to weight loss. But the truth is they are no better or worse for overall weight loss compared to any other dietary intervention (1).
What Is The Ketogenic Diet?
The ketogenic diet is a low-carb diet as well, but it’s very low-carb, to the point where the body begins to use fat as fuel rather than glucose.
Fat isn’t used directly as fuel. This is impossible. What happens when you enter “ketosis” (fat burning) is that fat is converted into the fuel source referred to as ketones.
These ketone bodies – beta-hydroxybutyrate (BHB), acetoacetate, and acetone – move through the bloodstream and are utilised by organs in the body. Ketone bodies also enter into the mitochondria, which are the power plant cells of the body.
Typically the ketogenic diet is 5% carbohydrates, 25% protein and 70% fat.
But ketones can be produced without eating certain foods. In fact not eating anything until your reserves or sugars are depleted will cause ketones to be produced and utilised as energy, this is also known as fasting.
This can also happen on a low-carb diet, but the idea with the ketogenic diet is to sustain ketosis as the primary means to fuel the body instead of glucose which allows an individual to become “fat-adapted”.
Ketosis, contrary to some claims, is a perfectly normal metabolic function. Ketosis will occur when carbohydrates are under 50g or more correctly 5%. This number/percentage depends on you as a person, your metabolism, your activity level and other genetic factors.
When you’re blood ketones reach between 0.5-5.0 millimoles this is generally regarded as the ketosis zone, 0.5 – 5.0 being light to deep ketosis respectively (2).
One popular criticism of the ketogenic is that it’s “high protein” like many low-carb variations. We all know that too much protein means an increased risk of certain cancers as well as other unpleasant experiences such as constipation, right? Well, the ketogenic can’t be high protein, by the very definition of what a ketogenic diet implies.
Protein on a ketogenic diet is important because the brain still needs some glucose for certain functions which protein provides through gluconeogenesis. But with too much protein, too much sugar is metabolised and thus ketosis wouldn’t be occurring on a consistent basis.
Now there are some risks involved with a ketogenic diet if it’s not done right, nobody is denying this, but this is the same with absolutely any diet which places emphasis on specific nutrients.
Ketosis And Endurance-Based Athletic Performance
For athletic performance (explosiveness and strength), ketosis tends to not favour optimal performance. Gaining muscle is slightly more tricky when on a standard ketogenic diet with minimal carbohydrates, but it is certainly still possible despite some claims. This is why cyclical ketogenic diets and targetted ketogenic diets are often spouted to be recommended for athletes.
Remember the insulin response from carbohydrate intake has a lot to do with muscle growth (3). In saying that, carbohydrates aren’t required for protein synthesis as much when your body becomes more fat-adapted.
Our body is made to adapt to change, that’s what humans specialise in. It would make no sense from an evolutionary perspective for us to lose our ability to adapt and grow in response to stimuli with the absence of carbohydrates in nature.
The body has to change, it adapts and it will become more efficient with its use of the glycogen it has available.
However, there is a lot of potential for ketogenic diets favouring certain athletes, namely long-distance endurance athletes (3).
Anecdotally I find that when I’m in deep ketosis I can hold my breath for much longer than I’d be able to on a normal carbohydrate dominant diet and this isn’t a coincidence or placebo and this experience isn’t just happening to me.
A study compared 10 high carb athletes with 10 high-fat athletes. The results showed that performance was the same and high fat was utilising more fat from their own bodies (4).
There may be some studies showing a less optimal performance on the ketogenic diet, but many of these aren’t testing people who are keto-adapted, which makes a big difference.
I suggest reading this article here which outlines an n=1 experiment testing the volume of oxygen consumed (VO2 max) pre and post ketosis. The results showcase a more than two-fold increase in over twice as many calories burned.
Ketosis And Weight Loss
In terms of weight loss (which is why most people do the ketogenic diet), there’s some clear potential for short-term rapid weight loss and has been used as a means to make weight classes for sports such as martial arts or gymnastics.
When you go on keto you immediately shed a lot of water so many people get the impression it’ somehow superior for weight loss, but this isn’t exactly true.
In general though because the diet is more satiety and you lose cravings form carbohydrates which are symbolic some of the most unhealthy foods which have a lot of processed sugar and this calorie, it becomes an appealing option to the obese who want to eat tasty food like bacon and still lose weight.
So just like fasting, for weight loss keto isn’t going to do anything magic. But for fat loss that’s a different story. Because you’re utilising not only your dietary intake of fat for fuel but also your fat you hold on your body, there’s some research showing that the ketogenic diet may allow you to lose more fat and keep more lean body mass when losing weight.
However, when keto is done wrong, meaning you’re eating processed meats and even too much dairy, it can become problematic in my opinion and in my experience.
For example, your gut health and general well-being may be negatively affected by doing keto the wrong way with too many unhealthy fats and too little omega-3 necessary may cause a decrease in brain-derived neurotrophic factor (BDNF) which is responsible for neurogenesis – the birth of new brain cells (5).
Ketosis, The Brain And Disease
Keto was actually invented for epileptic patients who had seizers and is now being studied as a potential treatment for certain cancers which thrive off of sugar as well as for the alleviation of Alzheimer’s and Parkinson’s.
Here’s an explaining how the ketogenic diet effects your brain which you can watch in the link above.
The most noteworthy benefit which is now regarded as quite obvious is the effects it has on lowering insulin, which is why it improves triglyceride levels and all markers for metabolic syndrome making it a great option for type 2 diabetics.
However, for many of the above relating to cancer, more research needs to be done to explore much more before we can make very strong statements about what keto is capable of doing for cancer and cognitive disorders. Because there are also certain cancers which thrive off of fat, so it’s a perplexing matter as with everything in nutrition.
One major Ketone, beta-hydroxybutyrate, or BHB, provides more energy per unit of oxygen than glucose and thus may be even more efficient than glucose at providing energy to the brain.
Additionally, the mitochondria or the powerhouse plants of the cells are left with less metabolic waste, meaning they work more efficiently and even increases the total number of mitochondria in brain cells. Furthermore, the ketogenic diet increases BDNF or brain-derived neurotrophic factor which is what allows the growth of new brain cells (neurogenesis) to occur (6).
The studies, which have been mostly animal-based show greater gene expression for mitochondrial enzymes with the hippocampus. The hippocampus is responsible for learning and memory.
What’s The Main Difference?
Alright, enough with the benefits. Let’s get straight to the point. What’s the main difference?
Let’s say that 50g of carbohydrates was your threshold for ketosis. Using this example, this would mean that anything over 55 g per day would shift you out of ketosis.
This 5g difference has a huge impact on your metabolic function, but you’re still in a low-carb, actually a very low-carb diet. This is oversimplified, but this illustrates the main point.
Now low carb and keto diets do share many commonalities, namely the reduction of carbohydrates, less insulin, more control over blood sugar levels and cravings and a reduction in the risk of certain cancers and even heart disease. But as I’ve said previously low carb is vague and keto is definitive.
Many of the benefits I’ve spoken about for the brain and weight loss are much more pronounced when the metabolic switch to a primary source of fat as fuel is made.
Which Diet Is Superior?
The thing with the ketogenic diet is that it works, you can feel great on it, but it’s a hit and miss. It’s low carb, high fat, sure, but it’s not as simple as that.
When you’re new you have to monitor your sodium levels, magnesium intake and be sure to hydrate and tone it down on the exercise. So as an ordinary person, it may be too socially eccentric and slightly annoying logistically.
This is why I always recommend fasting as your backbone and staple. It provides you with many of the benefits of the ketogenic diet but allows you to eat a more flexible diet. But if you want to do keto, it can be done and it can be awesome.
So the problem with low-carb is that one may lack all the benefits which come with raising your fat and almost eliminating carbohydrates.
You’re going to perform well if you’re either heavy glucose dependant or heavily ketone dependant, if your primary source of fuel is glucose and you don’t have much of it, well then my logic says your performance will likely suffer. Perhaps I’m wrong here.
Both ketogenic diets and low carb diets are low carb. The difference is that the ketogenic diet gives one various benefits which only come with the metabolic switch of being in ketosis – often this doesn’t occur with a generic low carb diet.
Keto may potentially be better for endurance based exercise and is not optimal for muscle growth, although still very possible to experience consistent muscular hypertrophy.
Keto can be awesome, you feel great on it if you do it right, but it also takes some time to adjust to the types of food you eat and also it can be challenging in terms of social and practical daily events.
If you’re going to do keto, then go all in and don’t judge the experience by the first week. you may find that many of the things you don’t like about it go away once you’re fat-adapted.
At the end of the day, it all comes down to choosing a nutritional plan that’s going to be best for you long-term.