At a glance:
- Great for losing weight fast
- Easy to stick to due to reduced appetite
- Great for endurance athletes – burning fat provides sustained energy
- Nice and flexible – no prescribed meal plan, so flexible choices in what you eat
- Heaps of health benefits, as long as you don’t go overboard
- Some downsides, including keto flu (which can be managed)
- Not great for lifting heavy weights
- No more chocolate 🙁
|Simplicity:||(3.5 / 5)|
|Sustainability:||(4.5 / 5)|
|Flexibility:||(4.5 / 5)|
|Weight-loss:||(5 / 5)|
|Average:||(4.4 / 5)|
A ketogenic diet is a very low carb, moderate protein, high fat one which aims to end up with the individual in ketosis. Being in ketosis means that the body has used up its carbohydrate/glycogen stores, and is relying on energy from stored fat instead. In ketosis, an individual’s liver breaks down fatty acids to produce ketones (or ketone bodies) for cells to use as energy. Ketosis normally occurs when food intake is low – it’s our body’s way of adapting to low food conditions. By drastically reducing your carbohydrate intake, you effectively trick your body into thinking food intake it low (it’s totally not though!), and burning fat stores to compensate. Awesome!
Alright, give me the low-down
So, as I said, the ketogenic diet (which I’ll just call “keto” from now on, because that’s what most practitioners of it call it), is a very low carb, high fat, moderate protein diet. In fact, you’re aiming to get around 70% of your total daily calories from fat! Sounds like a lot, but because fat is so much more energy-dense than are carbs or proteins, it’s not as bad as you think (i.e., you’re not going to have to chug olive oil to hit your goal. Peanut butter, on the other hand, is fair game…).
The remaining 30% of calories should be split between proteins and carbs – 20-25% from protein, 5-10% from carbs. As in, between 20-50g net carbs a day, MAXIMUM. Like I said, very low-carb. This is especially important in the early phase of keto – the more you restrict your net carb intake, the faster your body enters ketosis, and the faster you start burning away your fat stores.
You might have noticed that just before I was talking about “net” carbs. What are they? Easy!
Net carbs is simply the total grams of carbs in a serving of food, minus the grabs of fiber. That’s because, even though fiber is technically a carb, it doesn’t affect blood sugar levels, as it doesn’t get digested (insoluble fiber doesn’t dissolve in water, and is important for digestion and bowel movement; soluble fiber forms a gel when dissolved in water, and helps us feel full for longer, slows the absorption of sugars, and helps reduce LDL, the bad cholesterol). As an example:
- You decide to eat 100g of cauliflower (why? Because it’s healthy, and 100g a nice round number, that’s why)
- Of that 100g, 5 grams are carbohydrates
- However, of those 5 grams, 3 are fiber.
- 5 minus 3 = 2. So your 100g of cauliflower has just 2g of net carbs!
So, when working out how many carbs you’ve eaten (or can eat) for a day, make sure that you’re working off net carbs – eat as much fiber as you want (the more, the better! It’s great for you!).
Where you source your carbs is up to you, but in general the best sources are non-starchy vegetables (spinach, asian greens like bok choi, broccoli, cauliflower, kale, etc.), nuts (be careful with nuts – some are higher carb than others, so always check before scoffing handfuls of them), and dairy (it’s hard to drink a reasonable amount of milk, as milk contains lactose, which is a sugar. Cream, however, is great, so you can still mix it with your coffee).
So, in summary: The keto diet is very low-carb, moderate protein, high fat, and doesn’t follow a strict meal-plan, like some diets – you can eat whatever you want, provided you’re hitting your macros (your goals for fat, protein, and carbs).
How do I know how much to eat?
There are two schools of thought on this. The first is that, because you’re eating high levels of fat and protein (which tend to make you feel fuller for longer), your appetite is naturally suppressed and you don’t need to worry about counting calories – just worry about your proportions of macros, and keeping your carbs very low. I disagree with this school.
The second, and in my opinion far more sensible school of thought, involves working out your average daily energy expenditure, and creating a detailed macro breakdown based on that, which you stick to using a calorie counter like MyFitnessPal (which is what I use). The reason that I advocate this approach is that people are generally bad at estimating the calorie content of foods. Sure, your appetite may be reduced on a keto diet, but that doesn’t mean that you’re going to magically eat under your maintenance calories and lose weight, particularly if you replace snacking on chips and lollies with snacking on nuts – nuts are extremely calorie dense. So, working out how much you need to eat to lose weight and keeping track of that, in my opinion, makes a lot more sense than winging it.
So how do you do it? There’s a form just a bit lower on the page which lets you plug in all the relevant data that will tell you just how much of everything you should be aiming for per day. However, before blindly filling it out, there are a few things you should be aware of.
- Your measurements. You should have a vague idea of how much you weigh (if you know your weight in pounds, divide it by 2.2 to get your weight in kilograms), and how tall you are (if you know your height in inches, multiply by 2.54 to get your height in centimeters). However, you may have no idea what your body fat % is. There are a number of ways in which to get this information, some of them better than others. The simplest and cheapest way is a visual inspection (also the least accurate). More reliable than that would be to use body-fat calipers, or bathroom scales that give you a body fat % rating (e.g., these). The most accurate of all is to get a DEXA scan, but it’s also the most expensive. For a general estimation, any of the methods I just mentioned should be fine. Working out your estimated BF% is important for determining your estimated lean body mass (which is important for protein intake – see below).
- Your activity level. It’s pretty self-explanatory on the form, but obviously the more active you are, the more calories you’ll burn on average. Be honest with this part!
- Your deficit. How much of a deficit you want (or can maintain) is going to depend on a number of factors. To explain further – it takes a deficit of roughly 3500 calories to lose a pound of fat. So, if over the course of a week you burn 3500 more calories than you consume, you should lose a pound – great! That works out to about 500 calories a day (7 days x 500 calories = 3500 calories). However, that may be more of a cut than you want to take – unless you’re used to eating 5000 calories a day, 500 calories is going to be more than a 10% deficit. Work out what you’re comfortable cutting, and enter that. It can always be adjusted later, so don’t stress about it too much!
- Carbs and Protein. As mentioned, you want to keep your carbs low – the calculator defaults to 20g, because that’s a good level to get you into ketosis quickly. If you want to eat more or less than that, you can change it manually (though it won’t let you put more than 50g/day). Protein intake should be between 0.7g-1.2g per lb of lean body mass per day. The lower your activity level, the lower your protein intake should be, as too much protein can actually prevent ketosis (due to getting converted to glucose). If you’re more physically active, you can afford to raise your protein intake somewhat.
OK, that’s all great, but what’s the keto diet good for?
A ketogenic diet comes with a whole host of health benefits.
- Reduced hunger. As mentioned, cutting carbs from your diet and consuming fats and proteins tends to leave you feeling full for longer, which means you don’t get the urge to eat all the time. This, in turn, makes it much easier to stay within your daily calorie goals.
- Lowered blood pressure, triglycerides, and bad cholesterol. I mentioned most of these in my “What is low-carb, anyway?” page, and the keto diet is no exception. Sticking to a ketogenic diet can provide significant benefits to all of the above, as well as raising your levels of good cholesterol.
- Drop in blood sugar. Obviously if you’re taking in less sugar, your blood sugar levels will drop, but a keto diet also reduces insulin levels, which means less fat storage, reducing problems like insulin resistance and type 2 diabetes.
- Energy. This seems kind of counter intuitive, but once your body adapts to burning fat as fuel, you’ll feel more energized during the day!
- Protein-sparing effect. Provided you’re consuming enough glucose (as mentioned above), your body isn’t going to feel the need to burn muscle mass for fuel, even in caloric deficit – so the weight you lose is primarily fat, rather than muscle.
- WEIGHT LOSS. This may be one of the major reasons you’re looking into dieting, and a keto diet is fantastic for this. In the short term it’s more effective than pure calorie restriction or a low-fat diet, and generally easier to stick to (due to feeling fuller).
The best way to know when you’re in ketosis is by using a product called ketostix. These can be found in most pharmacies, or ordered online. They only test for excess ketones in your urine, so just because they don’t show any doesn’t mean you’re not in ketosis – but if they do show something, you are. You can grab a box of 100 from Amazon here.
It can’t ALL be good, right?
No, it can’t. It mostly is, though, provided that you don’t go overboard. It’s very easy to go “I can eat all the cheese and bacon that I want” – that’s not a good way to approach this diet. You still need to consider essential micronutrients like trace minerals, vitamins, fiber, etc., and take care of your kidneys by not exclusively eating steak for 10 days in a row. Besides that, there are some downsides to keto diets, which include:
- Keto flu. This is the period of time where your body is adapting to using fat as fuel, and comes with flu-like feelings of fatigue, brain-fog, headaches, dizziness, etc. Remember, this passes, and can be somewhat ameliorated by keeping electrolyte levels (sodium, potassium, magnesium) high. Also, the lower your carb intake, the faster you get through this, so…drop those carbs!
- No more chocolate. Well, not the delicious kind. You can find sugar-free chocolate, which often uses various sugar-alcohols as sweetener, but…it’s not the same. Trust me.
- Less good for weightlifters/sprinters/etc. Some people claim that once you’re fully adapted, you’ll be back at previous levels of strength, etc. For endurance, this is certainly true – there have been recent studies with long-distance cyclists that have found that endurance on a ketogenic-style diet actually increases. However, for short, intense efforts (lifting heavy weights, short sprints, etc.), keto may not be the best – these types of exertion do tend to require stores of glycogen. If you’re determined to follow a ketogenic diet, you may want to look at CKD (cyclical keto diet) or TKD (targeted keto diet). These both involve ingestion of carbs at certain times to provide sufficient energy for your activities.
- Muscle cramps. These can occur with the loss of minerals, which happens as your body flushes a lot of water out. This, too, can be dealt with by taking slow-release magnesium, such as Jigsaw Magnesium tablets.
- Slowing weight loss. This is a bit of an odd one. As you get into ketosis, you will appear to lose a lot of weight very rapidly. The problem is, a lot of this is water weight – as your body uses up all of its glycogen stores, it ditches the water that was bound to the glycogen. Once this is gone, the rate of weight loss becomes more normal, and tied to caloric deficit – which can be disheartening. Don’t worry! As long as you’re eating at a deficit, your weight will go down. Stay strong!
Summary and Getting Started
There you have it – the Keto diet in a nutshell, with the pros and cons. I honestly think it’s an excellent diet, as it’s pretty flexible (provided you’re avoiding carbs, you can eat more or less whatever you want to meet your macros), and you do see results, often quite quickly.
It does, however, require a lot of meal-planning (or at least, that’s what I’ve found) – it can be very hard to find appropriate low-carb options when eating out, so it’s best to start preparing lunches where you can.
If you’re going to start a Ketogenic diet, I strongly suggest that you fully educate yourself about the diet and the effects it has on your body – I’ve tried to provide a reasonably comprehensive summary of the diet here, but it’s worth reading about it in much greater depth.
Make sure that you start tracking your food intake – I recommend (and use) MyFitnessPal, which makes keeping track of your foods a breeze. You will likely need to start weighing your food – I’d suggest getting an accurate food scale.
And if you’re stuck for food ideas, make sure you check out the recipes section of the site, or do a search for “Keto foods” to check out posts that I’ve written about that very topic!