Paleo vs Atkins vs Ketogenic Diet

Paleo vs Atkins vs Ketogenic Diet


Paleo, Atkins, Ketogenic… what the heck is the difference!?

The Paleo diet, Atkins diet and ketogenic diet have a lot of overlap - in fact, you can actually be on all three of these diets at once.

This overlap makes the three diets very easy to confuse and, it can make your decision on which diet is best for your goals a little bit tough.

But, as always, you’ve got a scientist on your side and, today, I’m going to clear up the main difference.

Let’s get started!

Paleo vs Atkins vs Ketogenic Diet: a Comparison

Ketogenic Diet

To start off, I’d like to explain to you guys a bit about a biological state called nutritional ketosis. Pay attention, because this is a pretty important concept that may be a major factor in your dietary decision.

Nutritional ketosis is a biological state in which your body begins using fats, rather than glucose, as it’s main fuel source. In order for fats to be used as fuel, they are converted into ketone bodies, which is the basic goal of the ketogenic diet.

Although more complex, cyclical ketogenic diets exist, in which you are cycling in and out of ketosis, with the basic ketogenic diet your body is in a constant state of nutritional ketosis.

In order to enter into nutritional ketosis, you must drastically restrict your glucose supply, while concurrently increasing fat consumption so that your body is essentially forced into burning fat as fuel. Your macro breakdown should look something like 60-80% fat, 5% carbohydrates and the remainder as protein.

As 1g carbohydrate is equivalent to approximately 4 calories, a 5% carbohydrate intake would equate to approximately 25g carbs daily for someone on a 2000 calorie per day diet.

Keep in mind, these numbers are approximations and each person will enter ketosis at slightly different values, depending on biological and lifestyle factors.

At first, while your body is still relying on the glucose hits you’re used to, you may experience some poor feelings such as low energy - but don’t worry, it’s about to get so good.

Burning ketone bodies as opposed to glucose as your main fuel source is accompanied by a vast array of biological benefits including enhanced cognitive functioning, stabilized energy and easier maintenance of ideal body composition. It can basically turn you into a superhuman.

As I mentioned, both the Paleo and Atkins diet can overlap with the ketogenic diet. What I mean by this is that you can be following the rules of the Paleo diet or Atkins diet and still be consuming enough fat to push your body into nutritional ketosis.

However, being in a ketogenic state is not necessary under the rules of the Paleo and Atkins diet and, you could certainly be on either of the latter two diets while still burning glucose as your primary fuel source.

What I’m getting at is, the main difference lies within the allowance for carbohydrate intake.

So, to reiterate the essential principle of the ketogenic diet is to use ketone bodies rather than glucose as your main fuel source, which is not an essential part of the Paleo or Atkins diets.

Let’s move on.

Atkins Diet

The Atkins diet has a few phases and, in the first phase, your daily carbohydrate allowance is as low as 20g carbohydrates per day. This low intake means that, depending on how long you stay in the first phase, you may actually enter into a state of ketosis during this phase and simultaneously end up on both diets for a temporary period.

However, by the end of the Atkins diet, your daily carb allowance moves up to 100g daily for maintenance, which is much too high for the average person to remain in a consistent state of ketosis.

One of the pitfalls of this, however, is that if your body is not in a state of ketosis and is still relying on glucose as a main fuel source, then restricting glucose intake may result in feelings of lethargy, reduced cognitive functioning and general unwellness depending on your biological needs.

Although there are still some pretty amazing benefits to being on a low carb diet which you can definitely experience during the maintenance phase of the Atkins diet, it’s important to remember that, whatever fuel your body is working with, you’ve got to give it enough to meet your energy requirements.

Paleo Diet

The Paleo diet is the most generous of these three diets regarding carbohydrate intake. On the Paleo diet, you can consume up to 150g carbohydrates daily, depending on what your personal goals are.

For example, athletes may choose to consume a much higher amount than this, whereas someone aiming for weight loss might choose to consume less carbs.

Additionally, the Paleo diet encourages the consumption of certain fruits and vegetables that would not be primarily recommended on the ketogenic or Atkins diet due to carbohydrate content.

The basic principle of the Paleo diet is simply to eat foods that are natural, and that our ancestors likely consumed. Therefore, as long as you can find it in nature, most foods are A-okay.

Due to the generous carbohydrate allowance and vast array of allowed foods, I personally find the Paleo diet to be the easiest of the 3 to follow.

Choosing Which Diet is Best fo​r You

In order to select the diet that’s best for you, you’re going to want to consider the following 3 factors:

1. Health Goals

The first thing to do is ask yourself what are your health goals.

If you’re aiming for fast weight loss, perhaps Atkins will be the right fit for now. If you’re aiming for enhanced cognitive functioning and stabilized energy, the ketogenic diet might be more your style. And, if you’re aiming to simply boost your health and body composition without being overly strict, the Paleo diet could be your best fit.

In my opinion as a scientist, if you’re going to be pushing your body into a low-carb state, the ketogenic diet is pretty unbeatable in terms of biological benefits. I practiced this diet for nearly two years during my Master of Science degree, a point at which I was simultaneously ill with a variety of ailments.

During my time on the ketogenic diet, I noticed dramatically increased focus and productivity and, being the scientist that I am, I monitored numerous biological markers and experienced drastically improved health status, even for problems that I wasn’t centrally focussed on.

Basically, everything moved in the right direction while I was on keto. However, for reasons I’ll discuss below, this diet isn’t right for everyone’s body and, despite a nearly two-year stint on it, I don’t even continue this way of eating due to personal sustainability.

2. Personal Preference & Sustainability

The next thing to consider is how sustainable do you consider each of these diets to be.

As I mentioned, although I experienced amazing benefits on the ketogenic diet, I always felt restricted and also felt that sticking to a strict diet while socializing was difficult.

That was my personal experience - however, some people can go years doing the ketogenic diet without any feelings of restriction.

Keep in mind that if you’re constantly feeling restricted and stressed over your diet, this is going to be negative for your mental health, stress hormones and therefore, your overall well-being.

Your diet should be enjoyable and sustainable, and certainly not stressful.

3. Dietary Personalization

Now that you’ve combined your health goals with a diet that you find sustainable, the final factor is considering dietary personalization.

What this means is that, even though one diet may be considered scientifically beneficial, or has worked great for one of your friends, the fact is that every person’s biology is so individual, and different diets will work for different people.

So, when testing out your selected diet, be sure to pay attention to how your body is feeling. Sure, your body will take time to adjust to any new diet and you may not feel perfect during this period (especially if it’s your first time trying out the ketogenic diet) but, if after several weeks your body is not thriving on your new diet, it may be time to quit.

Keep this factor in mind, as many people push themselves through diets they are clearly not thriving on, simply because that diet has worked for other people. You and your biology are UNIQUE!

The bottom line is, do what’s right for you. Sometimes, what’s considered the “best” diet by science, isn’t necessarily the best diet for every single case. You are with yourself 24/7, so you know your body better than anyone, you just have to listen closely to find the answers!

Let me know which diet you decide to try out in the comments below.

Health begins in the gut.

Your friendly neighborhood scientist,


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