An Introduction to the Ketogenic Diet

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If you haven’t been living under a rock for the past year or so, then you’ve most likely heard of the ketogenic (or keto) diet.

If you have been living under one, I’m going to need you to crawl out from under it and take a seat because Ketogenic Dieting 101 is about to begin.

So, Like, What Is It?

Keto is a diet with high fats, moderate protein, and restricted carbohydrates. Initially designed to help children with epilepsy, it’s garnered attention for its effectiveness in regards to fat loss.

The traditional ketogenic diet (also known as the therapeutic ketogenic diet), mimics the effects of starvation by forcing the body to burn its own fat stores rather than glucose. When you restrict carbohydrates, the body enters into a metabolic state known as ketosis, where the liver converts stored fat (triglycerides) into ketones.

These ketones are what the body uses to fuel your brain, organs, and muscles.

On the therapeutic ketogenic diet, the macro breakdown looks like this:

However, as the ketogenic diet’s grown in popularity, especially among people who are looking to lose fat and build muscle, a new form of the diet’s emerged.

While the traditional ketogenic diet is an extremely high-fat diet with sufficient protein intake, the physique ketogenic diet is a high-fat diet but with adequate protein intake.

Huh, Sufficient and Adequate Protein Intake?

This is where a lot of the confusion arises around the ketogenic diet, and it’s important to understand the difference.

When the goal is fat loss, the concomitant goal is to preserve muscle mass. On a therapeutic ketogenic diet, protein is set to around 10-15% of total calorie intake. This is the sufficient amount of protein required to keep the body functioning and you healthy – basically so you don’t die.

The problem is, this is far lower than what is optimal for those who engage in regular high-intensity training, like weight lifting. For people who engage regular strength training, the protein requirements are much higher (between 0.8 – 1.2g/lb of body weight). This is the adequate intake. It’ll help preserve and grow muscle while aiding with recovery.

With these alterations, the macro breakdown looks like this:

Fat intake still makes up the majority of the diet, but is slightly reduced so that protein intake can be brought up to a sufficient amount.

Quick note: In the examples above, I’ve used percentages to denote the breakdown of the macro intakes. This is only to give you an overview of the differences between the two different ketogenic diets. I prefer using bodyweight (instead of percentages) to set calories and macro intake, as it’s far more accurate.

Based on this, carbohydrate intake is usually set between 30-50 grams per day.

Protein intake is set between 0.7 – 1.2g per pound of bodyweight per day.

And then the rest of your calorie intake is filled with dietary fats. We’ll figure out this number by subtracting the carbohydrates and protein from total number of calories you should be eating per day. 

Don’t worry if you’re confused right now, this will all make sense by the end.

Why Should You Do Keto?

Great question. And the truth is, you don’t have to.

Wait, what?

Yup. I know this sounds totally crazy because the internet loves to tell you that you must do this or that, but the ketogenic diet, like any diet, is simply a tool. 

That said, it’s a super effective tool. When I experimented with the diet, I discovered these benefits: 

Healthy Food Focus

Look, I know healthy food and healthy eating has become the butt-end of lame jokes in the fitness world, but eating healthfully is important. Due to Keto’s low carb, high fat nature, you’re inevitably going to be eating more veggies, lean meats, and healthy fats – all of which are conducive to looking and living better.

Appetite Suppression

This is perhaps one of the most-documented benefits of the ketogenic diet. The number one enemy to the success of a diet is hunger. And the ketogenic diet has a very strong appetite suppression effect. As a result, you’ll find adhering to a calorie deficit far easier

 Improve Insulin Sensitivity:

Good insulin sensitivity means better partitioning of nutrients and poor insulin sensitivity (also known as insulin resistance) means poor partitioning of food, this can lead to increased fat gain and worse, metabolic syndromes like diabetes. Now, if you’re already lean, chances are your insulin sensitivity is good, but if you’re overweight, lowering carbohydrate intake can help improve poor insulin sensitivity.

Stable Energy Levels

Due to the reduction of carbohydrates, people tend to see fewer swings in energy levels and resultantly tend to feel better throughout the day.

Mistakes People Make

One of the reasons the ketogenic diet gets such a bad rap is because people give it a try, make these common mistakes, and then they feel like crap and their performance suffers. Don’t fall into these same traps.

  • They don’t consume enough fat. When people think of a ketogenic diet, they think, low carb, but this isn’t a low carb diet, it’s a high-fat diet. You need to be eating enough fat because it’s what your body will be using for energy.
  • They think calories don’t count. Sorry. There’s a buncha crazy people on the internet who claim that eating fat, somehow, overrides the first law of thermodynamics. It doesn’t. I know, it’s lame. So, pay attention to your calorie intake and how much you’re eating. Seeing that fat contains double the amount of calories in carbs and protein can make it very easy to overeat.
  • They don’t pay attention to electrolytes. When you remove or greatly restrict carbohydrates in the diet, your body will drop water and along with that, electrolytes: salt, potassium, and magnesium. Electrolytes play an important role in the body and an imbalance can lead to feeling nauseous, weak muscles, and severe cramping. So, ensure you’re staying on top of these (more on this below).
  • They don’t allow time for adaptation. To fully begin reaping the benefits of the ketogenic diet, there is an adaptation period. This period can last anywhere from three to six weeks, some will transition sooner, while others will take longer. Generally, four to six weeks is enough time for this transition to happen as long as you’ve set up your diet properly. During this time, you might experience some symptoms of “the keto flu”; this is something you will need to see out. It shouldn’t be too bad as long as you’re staying hydrated and keeping on top of your electrolyte intake.
  • They try to force keto. This is the biggest mistake I see people making. Look, not every diet is for everyone. If you try a ketogenic diet, and you find that you feel bad and your performance is taking a hit (after giving your body time to adapt), stop the diet. Don’t force it.

Is The Ketogenic Diet For You?

This is where I’m annoyingly ambiguous and say, “It depends”. The ketogenic diet is an extremely restrictive diet, and it isn’t for everyone, here are some people who could benefit from it.

  • Those who have a preference for higher fat foods
  • Obese or overweight individuals: Insulin resistance tends to be higher in folk who are overweight and obese. Reducing carbohydrates to a ketogenic level seems to improve insulin levels. Their energy tends to increase, reduces sugar cravings, and helps with appetite control.
  • Some people just feel, perform and do better with a low carb, or ketogenic diet. I definitely fall into this group. And unless you experiment, you won’t know.

But, there are also people who probably wouldn’t do so well on a Ketogenic Diet.

  • Performance athletes: If you’re a performance athlete or someone who engages in high-intensity training like Crossfit, Powerlifting, Sprinting, Rowing, etc. you’ll do better with a carb-focussed diet.
  • Just like there are those who innately do better with a low-carb diet, there are also those who innately do better on a high-carb diet.

Setting Up Your Own Ketogenic Diet

Whew. Ok, now that we’ve got all that theory out of the way, if you’re still reading this, chances are you’re considering trying it for yourself, which is excellent because that’s what we’re now going to talk about. 

Determining Calorie Intake

First thing we need to do is determine your calorie intake. While there are a myriad of online calculators that you could use, I find the simplest way to be the best. 

To set your calories, simply, take your bodyweight (in pounds) and multiply it by 10-14. Women should stick to the lower end (10) and men to the higher end (14). 


If you’re a 170lb male, multiply your bodyweight by 13-14:

So, 170 x 13 = 2210. These are your calories for fat loss. 

If you’re a 140lb female, go with 10-12 as a multiplier: 

So, 140 x 10 = 1400. These are your calories for fat loss. 

Setting Macros

Once your fat loss calories are set, we then need to set up your ketogenic macros. If at this point you’re staring blankly into the screen wondering what a macro is, don’t fret because RFS has you covered.

Go read that quickly and then come back. Don’t worry, I’ll wait.

Done? Good. Let’s carry on.

We know that on a ketogenic diet, carbohydrates are set between 30-50 grams, for the sake of simplicity we’ll go with 50 grams. After carb intake, we’ll set protein intake.

Important note: during the first few weeks of transitioning into ketosis keep your protein intake close to 150 grams (for both male and female). As you restrict carbohydrates and the body transitions into ketosis, it will use muscle protein to make glucose, the 150 gram mark will offset any muscle loss while not interfering with the transition.

After this time – usually the first 4 weeks – you can increase protein intake up to 1.2 grams per pound if you wish. If not, you can keep protein at 150 grams.

And lastly, you’ll set your fat intake with the remainder of calories left (in your previously calculated daily total) after carbohydrate and protein intakes are set. 

Let’s put this all together using a hypothetical example.

First, we’ll need to figure out this hypothetical person’s fat loss calorie intake. Let’s assume he’s male and weighs 180 lbs.

Calorie intake: 180 x 14 = 2520 calories per day

That’s his calorie intake for fat loss. Now we can start setting his macros.

Set carbs first: 50 grams (because it’s 50 for everyone).

Protein intake second: 180 x 0.7 = 126 grams

And finally, we set his fat intake by simply following these four steps.

  1. Work out the number of calories coming from carbs and protein.

50g (carbs) x 4 (number of calories in one gram of carbohydrates) = 200 calories

126g (protein) x 4 (number of calories in one gram of protein) = 504 calories

  1. Add carb and protein calories together: 200 + 504 = 704 calories.
  1. Deduct the carb and protein calorie total from the total calorie intake: 2,016 – 704 = 1,312 (this is the number of calories left over to put toward fat intake)
  1. Work out fat macros: simply divide 1,312 by 9 (9 is the number of calories in one gram of fat): 1,312 / 9 = 146 grams of fat (rounded up).

So, our hypothetical person’s calorie and ketogenic macros look like this:

Calorie intake: 2,016 calories per day

Carbs: 50 grams per day

Protein: 126 grams per day

Fat: 145 grams per day

A Note on Carb Sources

This is an extremely low carb diet, and so you’ll be best served restricting carbohydrates strictly to vegetables and fruits like berries. There isn’t any need to track these. Some people will claim that you should track things like tomatoes, carrots, and peppers. Honestly, this is silly to me. Feel free to consume all veggies without worrying about tracking them – they’re all extremely low in calories, and unless you plan on eating truckloads, there’s nothing to worry about.

Nobody has gotten fat, or been unable to lose fat because they overate on a damn salad. You get the idea. Veggies, they’re good for you. Eat them.

Foods to Avoid:

  • Grains (rice, cereal, bread) anything starchy like potatoes and pasta.
  • Heavily processed foods like cookies and candy.
  • Refined fats and oils like, sunflower, safflower, canola, soybean, grapeseed.
  • Trans fats (margarine)
  • Fruits, except for berries


Earlier in the article, I touched on the importance of electrolytes, and seeing that they’re of utmost importance on this diet, it’s only right I dedicate a section to them.

  • Sodium – this is simply table salt. Staying on top of sodium intake is essential. Almost every time I speak to someone who has had a bad experience on keto, they’ve been neglecting their sodium intake.Aim for 3-5 grams of sodium per day. Contrary to what you might hear, you’re more at risk from a lack of sodium than from too much. Now, this doesn’t mean you start taking salt by the spoonful; just salt your meals to taste and you’ll be fine.
  • Potassium: an electrolyte that is required by your body to function properly.It’s a good idea to balance your salt to potassium intake on a 1:1 or 2:1 ratio – salt:potassium. So, if you’re consuming 5 grams of salt per day, aim to get 2-5 grams of potassium.
  • Magnesium: Magnesium is a crucial mineral that is needed for the contraction and relaxation of the muscles, the production of energy, and can improve insulin sensitivity. While magnesium can be obtained through the diet, due to inefficient absorption, it’s a good idea to supplement.Take about 200-400mg per day (women on the lower end, men on the higher end).

The Keto FAQ

Some of the questions I’m commonly asked about the ketogenic diet.

Won’t I lose muscle if I cut out carbs? When calories are reduced there’s always a chance of muscle loss, but as long as you’ve set up your diet properly and are resistance training, you won’t lose any muscle mass.

But, I need carbs for energy, don’t I? while I won’t deny that carbs can most definitely aid performance, they’re not as necessary as you might think. And as long as you set your ketogenic diet up properly – including electrolytes – you’ll be surprised by the amount of energy you have.

Won’t I die if I eat large amounts of fat? Perhaps if you were also consuming high amounts of carbs, but seeing that dietary fat is the main energy source on the ketogenic diet, you have nothing to fear about a high fat intake. Further, there isn’t any evidence to suggest that consuming high fat leads to any health risk.

Are you sure? Yes. I’m sure. I had my blood tested after 6 weeks on almost 200 grams of fat, most of which was of the saturated kind. And everything was in order.

Do calories still count? Yep. Some in the keto world will claim that you can eat as much fat as you like, which is patently false – calories still count on a ketogenic diet. And if fat loss is your goal, you’re going to have to create a calorie deficit.

Hey, so I’m on keto and I…uh…can’t poop? It’s because you’re not consuming enough fiber. Make sure you’re eating ample amounts of fibrous veggies like broccoli, cauliflower, courgettes, mushrooms, etc. You can also supplement with a fiber supplement like psyllium husk.

Can I build muscle on keto? Maybe. I’m not convinced it’s the best thing, though. Keto works great for fat loss, but if you’re wanting to build muscle, I recommend having a moderate amount of carbs in the diet (100-150 grams).

Try It For Yourselves

While the ketogenic diet can work brilliantly for fat loss, just remember that it’s not for everyone. Give it a go and see how you feel. If you find it doesn’t suit you, that’s cool, stop doing it.

The number one key to success with any diet is adherence, and what you can stick to is what will help you with your health, fitness, and body composition goals.

About the Author

Hi, I’m Aadam. Yes with two A’s. I dunno. Anyway, this is the part where I write some pithy shit about myself and then you go, “Wow, he seems super interesting. I’m totally going to check him out”. Well, I hate bios, so I’m not writing one. But, if you did enjoy this, you can read more about my 6-month ketogenic diet experiment here. You can also stalk me on Facebook.

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