Ketogenic diets (or simply: keto) are among the most popular diets right now. Reddit community about ketogenic diets has around 2 million members. The main idea of ketogenic diets is simple: drastically reduce carbohydrate intake so that your body is forced to use fat as the main source of energy. In the process of fat metabolism ketone bodies are created and they serve as an alternative energy source instead of glucose. When your body switches to using ketones as the main source of energy, you enter ketosis. Ketosis can be confirmed by analyzing your urine or breath for the presence of ketones.
There are many reasons that make keto diet attractive to people who want to lose weight, especially if they want to lose it quickly:
- When you cut carbs you lose a few pounds almost immediately. Even though this is mostly water loss (you’re depleting your glycogen stores in your liver and muscles and glycogen binds certain amount of water with it), this quick and immediate weight loss is very encouraging for dieters and boosts their motivation.
- Keto diet is simple – you don’t have to plan your meals or count calories, you simply avoid all the foods with significant amount of carbohydrates (grains, legumes, potato, bread, dough, pasta, sweets and fruits) and you eat all the rest without stressing about quantities and without restrictions.
- Keto diet is easy to follow – once you enter ketosis, your blood sugar stabilizes and you’re usually not feeling very hungry. Some people even report feeling more energized or increased mental clarity. Ketogenic diet is also used to treat epilepsy and can prevent seizures.
- Generally, low carb diets, might be somewhat more effective in causing weight loss than low fat or low calorie diets – or in other words, people love keto and other low carb diets, because they work.
- On keto diet some calories are lost simply from breathing out ketones before they are even used for energy. This amount is very low and there’s some speculation about whether this contributes in any significant way to weight loss.
- Keto diet allows you to eat some quite nutritious and substantial foods such as meat, vegetables and even some amount of nuts. For this reason, people usually don’t feel very deprived on this type of diet.
For all these reasons, coupled with general popularity of low-carb diets, such as Atkins diet, Keto has gaining a huge following.
But is this enough to really convince me to jump onto the keto bandwagon?
Well, at one point it was. Though at that time I didn’t call it “keto” I called it “Atkins diet” which is quite similar, though a little more permissive when it comes to carbs. While I was doing Atkins all that I ate was meat, fish, eggs and vegetables (a lot of vegetables) and occasionally some nuts. And that was it. From the point of view of short term weight loss the diet was successful, I lost around 10 kilos easily (22 pounds), and after the diet ended, I even managed to maintain it for 2 years. Also I found it easy to stick to the diet in the short term and I didn’t feel hungry. I had good energy levels. The only major issue I had were the gut problems. Namely, constipation, stool consistency, etc…
But, would I do it again? – No.
Would I recommend it to others? – No.
And here’s why:
- Keto diet is not as easy and sustainable as it seems at first. – While it is true that you won’t be hungry and that you will have normal energy levels, over time you’ll accumulate psychological fatigue due to eating always pretty much the same things (meat and veggies). The diet becomes more difficult with time as you get more and more bored of eating the same foods. Also, minor difficulties such as gut problems, over time become annoying, to the point where you start asking yourself: why am I doing this to my body?
- On keto diet you might be eating too much fat, or too much protein, or both. Simply the fact that you’re basing your entire diet on mainly animal products (as those are the products with lowest carb content), or fatty plant products (nuts, seeds, etc…), you’re likely to consume lots of proteins and fat. While this is good for preserving your muscles as you lose weight, this can, over time become taxing to your body. Eating too much fat is linked to heart disease, atherosclerosis, cardiovascular problems, and eating too much protein can become taxing to your kidneys.
- Keto diet is one of those diets I warn people against – such diets typically remove entire food groups from your eating plan – in case of keto – it removes as many as four food groups:
- grains, pasta, rice starchy vegetables (like potatoes)
Even removing just sweets completely could be problematic in the long term if the person likes sweets, as it might make the sweets even more attractive (forbidden fruit effect). But removing 3 major food groups – it is almost insane! Almost all nutrition experts agree that eating fruit and vegetables lowers all cause mortality and might prolong life and is beneficial to health in numerous ways. Grains too, especially whole grains are excellent sources of slow energy, are packed with dietary fibers and vitamins… Removing them from your diet is hardly justified for healthy people.
Of course there are legitimate uses of ketogenic diet: in the treatment of epilepsy. But if you’re an overweight or obese person who is otherwise healthy, there’s no reason to do this to your body.
Staying on keto for a long time might cause you to accumulate certain nutritional deficiencies as well unless you’re taking supplements as a precautionary measure.
- Keto is not much more effective than other weight loss diets – initial quick weight loss on keto is mostly due to glycogen and water loss. Afterwards, you lose weight pretty much in exactly the same way as on any other diet – by being in calorie deficit. You simply consume less calories than you spend. There’s nothing magical about keto that makes it more likely to work than any other diet that cuts calories. Keto is however attractive to people because it cuts calories in an indirect, unnoticeable way. Simply by removing all these food groups from your diet and forcing you to eat mostly just meat and veggies, you end up consuming less calories even if you don’t try, because to consume more calories you’d need to eat tons of meat and veggies, and you simply can’t… you’d feel sick from all that meat and fiber. So on keto the real reason for weight loss is eating less calories, even if it’s not achieved through calorie counting or direct calorie restriction. Now, keto might indeed be, slightly, slightly, very slightly more effective for 2 reasons, but the amount of this advantage is very small, almost marginal:
- it takes more energy to digest fat and protein than it takes to digest carbs. So when you base your diet on fat and protein, your energy expenditure slightly increases. However, this is true for all low carb diets, and going in such an extreme, entering ketosis, and going all the way keto is not necessary to achieve this effect. You could as well take advantage of this by simply substituting a part of your carbs with fat or protein, instead of ditching them almost completely.
- When you’re in ketosis, your fat metabolism produces ketone bodies, which are used as energy source. A tiny part of these ketones is breathed out unused which is wasted calories. However this amount is so small that you can safely ignore it.
The main take home message though is: keto is not any kind of magical solution and the real reason why people lose weight on it is because they consume less calories than they used to before going keto. Further special advantages of keto that I just described contribute very little to the total weight loss (perhaps 3-4% or even less).
People who do keto learn that it is true when they hit the wall. They expect keto to work like magic forever, but at certain point it simply stops working. They keep eating all the same keto stuff they did before but they are not losing any weight anymore. Why this happens?
Well, keto diet is in fact in some way the same like asymptotic nutrition approach, because it does the same thing, but without ever explicitly stating it. When you start keto you switch to a lower calorie intake, because you can’t push yourself to eat as many calories as before without certain food groups being present. So you start losing weight and you lose it as long as you’re in deficit. When your body weight becomes low enough, so that your calorie expenditure falls down enough to meet your calorie intake, you’ve reached a new equilibrium where you stop losing weight even if you continue eating the same like before. During the whole keto diet, in fact you’ve been asymptotically approaching your new equilibrium weight. When you stop losing weight you’re at that new equilibrium.
- The ultimate outcome of keto in the very long term is one of the following:
- sticking to it permanently, achieving sustainable weight loss, while at the same time risking damage to your health due to increased fat intake, nutritional deficiencies, gut problems, etc…
- eventually giving up, which will, most likely (unless you stay at that lowered calorie intake level) lead to regaining of weight and diet failure… which is a typical outcome of almost all diets which end.
- giving up keto, but staying on that low caloric intake level – this will mean you will succeed in the long term and maintain new weight, but this is quite difficult to achieve, as this involves designing a whole new diet AFTER YOUR EFFORTS WITH KETO… you can’t simply switch back to your old ways of eating, you need a new diet that’s as low calorie as your keto used to be, but inclusive of all food groups and sustainable. And starting such a diet after you’re already tired of keto is quite difficult. It would be much wiser to adopt such a diet at the very start AND instead of keto, because you’d achieve exactly the same result (lower calorie intake would equally lead to a new equilibrium like keto did), but unlike keto, such a diet would be one that you could stick to permanently.
- Now this is completely unrelated to nutrition – but still worth mentioning – if you have environmental or ethical concerns, you might not be happiest with the fact that your diet is so heavy on meat and animal products. I’m not a vegan or vegetarian, but I do recognize some of the arguments for vegetarianism, and while I haven’t decided to pursue it myself, I certainly wouldn’t recommend a diet that goes in the completely opposite direction either – being mainly meat based.
- And finally, as I believe that for overwhelming majority of people keto diet is not sustainable in the long term, you need to know that if you choose keto, and plan to maintain your weight afterwards, you gotta go on 2 diets: first keto, then post-keto maintenance diet – this just introduces unnecessary complication, and has quite low chance of success.
So, if you want to lose weight what to do, instead of keto?
First of all, check if you need to lose weight at all. Chances are you don’t.
If you do indeed need to lose weight, then bear with me:
Well, as you’ve seen – keto works mainly through lowering caloric intake. Lowering carbs has very little overall effect on weight loss, but avoidance of carb rich foods indirectly leads to lower calorie intake, and therefore to weight loss. But, as you have seen, keto is unsustainable in the long term and can be outright unhealthy (too much fat, cardiovascular health risks, etc…).
So the solution is simple… just lower the calories directly and be honest about it. No need to avoid any macro-nutrient. Carbs are fine, fats are fine, proteins are fine. No need to avoid any food groups. Directly address the idea that for weight loss to occur calorie intake needs to be lowered.
And for permanent weight loss, calories need to be permanently lowered (though just slightly).
As some of you already know, I am a proponent of Asymptotic Approach to weight loss which in a nutshell means:
- Skipping the restriction phase and going straight to the maintenance phase, which is intended to last forever, and which will cause your weight to asymptotically approach your target weight.
- By skipping the restriction phase you avoid the following problems:
- slowing down of metabolism
- feeling of deprivation
- need to exert lots of willpower
- complication arising from having to change your food habits not just once but twice (once when you start “dieting”, once when you start “maintenance”)
- “end of diet” mindset which leads to overeating
- “dieting” mindset which leads to belief that all the changes are temporary and that weight loss is the only goal – (in reality weight loss should be just a side effect of adopting healthy and balanced approach to eating)
All of this is avoided if you skip restrictive, “dieting” phase and go straight to the maintenance phase.
But how can I lose weight then, if I just do maintenance, you might be asking?!?!
Well you will lose weight because you’ll be eating the amount of calories needed at your target weight; NOT at your current weight. And as long as your current weight is higher than your target weight you will be in caloric deficit (because larger bodies requires more energy) and you’ll be losing weight. When you reach your target weight you’ll stop losing weight. However there’s no “end of diet” because asymptotic nutrition is not dieting, but a healthy, balanced, permanent way of eating. You permanently adopt a slightly lower caloric intake and when you reach your goal you just keep eating like that, and your weight will not move anymore.
So to apply asymptotic approach to weight loss the only thing you need to do is to determine your calorie needs at your target weight with your typical levels of activity and to permanently switch to this caloric intake, while trying to stick to a varied and balanced diet with all the nutrients and all food groups included. Adopting such caloric intake will cause your weight to asymptotically approach your target weight in the long term. How and why this happens, it’s explained in more detail in the main article describing asymptotic nutrition approach.
The trickiest thing here is, once you know how many calories you should be consuming daily, how to aim at that number. The simplest answer is through calorie counting, but many people are averse to calorie counting, and there might be many shortcuts and creative ways of achieving lower caloric intake, without explicitly counting calories. This however is a topic for another article. But here it’s worth mentioning that this is one of the reasons why keto is so popular: you lose weight (because you end up consuming less calories on average) without counting calories.
But what if I still want to do keto?
I don’t recommend ketogenic diets unless you’re an epileptic who needs such a diet to manage seizures. If you’re thinking about starting keto (or another keto-like diet) and aren’t convinced by my arguments against it, then I would recommend you to try to make your keto more sustainable in the long term. After all, going full keto isn’t needed and much of the same benefits could be reaped by simply lowering your carbs slightly without substituting them with other foods. Low carb diets aren’t without merit, they might especially be beneficial for diabetics and people with insulin resistance. But before starting any food regimen ask yourself: Could I continue eating like that forever? If the answer is no, modify your diet until you can enthusiastically say yes. Only then you’ll know that your diet is sustainable.