I’ll start by saying that this is the first post I’ve made that’s rather unscripted, so bear with me on the organization (or lack thereof). I’d like to touch on a topic that has made its way well into the fitness spotlight; something I’m asked about on a seemingly daily basis now. I’ll try to keep this short and sweet while also keeping it from becoming an all-out rant. After all, my aim is to educate.
I’d also like to make a disclaimer that I am in no way trying to command people’s lifestyles. I’m a libertarian at heart and believe that human beings should not control the lives of other human beings. At the end of the day, it’s your life and you should make the decisions and incorporate the habits that you see fit for your life. Again, my goal is simply to offer some insight.
It’s becoming ever difficult to ignore the prominence of the ketogenic diet (usually referred to as the “keto” diet) in popular culture. Often hailed as the most efficient way to burn body fat and get lean, the diet seems enticing at first. However, I’m writing to tell you that the keto diet isn’t a magical fix-it switch for your metabolism, and that it can do more long-term harm than good in many cases.
As always, I like to think of training and nutrition more in terms of a network of principles, rather than a rigid system. Basically what I mean is that progress in either endeavor is more reliant on how many mandatory boxes are checked off, not the fact that you followed whatever rules were set by by any given training or nutrition guru. That being said, the keto diet (or what most people define it as) can have the potential to be effective for some people… but not necessarily everyone.
To prevent this post from becoming a chapter out of a nutrition textbook, I think it would be most effective for me to write this in terms of claims made about the keto diet, followed by my personal feedback based on my education in the field of nutrition and physiology, along with my practical experience. And if you have yet to hear about the keto diet, let’s face it: you’ll probably hear about it via one of these popular claims.
I’m also not going to take the time to post references to studies and other published data. You can either do some of your own research or contact me for resources. To be frank, my responses are the result of 8 years of keeping up on research and applying it what I do for a living.
Claim #1: The keto diet forces your body to burn more fat because it puts your body in a state called ketosis.
Yes, ketosis is a real thing. In short, your body enters ketosis when carbohydrate stores and blood glucose levels are depleted and it must turn from glucose to an alternative fuel source. As a result, it manufactures ketone bodies, which you can think of as a poor man’s glucose molecule pieced together from fatty acids. In theory, it seems that this would lead to more body fat being burned to fuel the ketone manufacturing process.
However, this process will not: a) override the importance of caloric intake, which ultimately determines fat loss/gain or b) guarantee that you won’t also lose muscle mass, which is highly dependent on being fed glucose, aside from amino acids. Be aware that ketosis isn’t the end-all be-all.
Claim #2: The way to get into ketosis is to simply not eat carbs.
Ok, this one is also true… partially. If you really want to get into a state of ketosis, you mustn’t eat any form of carbohydrate, as the goal is glucose depletion. But, you also must avoid quite a bit of another macronutrient – protein. Given, this idea seems a little weird because most avid followers of the keto diet will go out of their way to eat very high amounts of protein.
The fact that protein can stonewall ketosis is due to a process called gluconeogenesis, in which your body converts amino acids to usable glucose molecules in the liver. This means that no matter how much sugar you’ve said no to, those chunks of meat you’ve been shoveling down are still keeping you outside the ketosis gates.
If you also have an interest in medical history, look up the original ketogenic diet prescribed by physicians decades ago. Some very intelligent people found that putting patients with epilepsy into ketosis worked wonders for minimizing their symptoms. There is also some similar research now showing that a ketogenic diet may slow or even halt the growth of certain cancerous tumors; really interesting stuff. The thing is, the diet prescribed to these folks is pretty different from what most people call the keto diet today, the main difference being that their prescribed diets were dramatically lower in protein – around 20% of total caloric intake from what I’ve seen. Why such low protein? Gluconeogenesis!
Another thing for all the ketosis gurus who preach eating tons of vegetables on the diet: vegetables contain carbohydrates too! Just because people don’t classify most vegetables as “starches” or “bad carbs” still doesn’t change their molecular construction. Carbohydrate is carbohydrate. Sorry.
So if you’re not one of those aforementioned patients and really trying to get into ketosis, you must drop the protein, too… and the vegetables as well. And if you have the will power to actually stay on a long-term diet that is high in fat and low in protein with virtually no carbohydrate (including veggies), please email me your food log. I’m genuinely interested.
Side note – it takes a long time for your body to transfer over to ketosis, a pretty short amount of time to get back out of it, and another long period of time to get back into it. So no, you can’t be in ketosis one day, gorge on fries the next day, and then be back in ketosis the day after that, no matter how much you think you can “feel yourself in ketosis.”
Claim #3: “If I’m not in ketosis, how come I’ve lost [insert number] pounds in the first two weeks!?”
Let me start with an overview of a fairly average person’s diet, broken down from a macronutrient standpoint:
- Protein: 20-30% of total calories
- Fats: 20-30% of total calories
- Carbohydrates: 40-60% of total calories
Now let’s assume that in hopes of achieving your ketogenic dreams, you drop all carbohydrates from your diet. This change alone means you’re dropping your daily calories probably anywhere from 40-60%, if you’re anything like most average humans. This means that your ~2,500 calorie diet is now a ~1500-1000 calorie diet – a rather aggressive deficit.
So yes, you may drop some body fat the first two weeks, but you will also drop a boatload of water weight from the muscle and glycogen that you are burning. Honestly, this is just crash dieting 101 and can be applied to many restrictive fad diets that promise a large initial weight loss and ultimately leave people almost just as fat with a lot less muscle and a damaged perspective on nutrition.
Interestingly, research shows that when a ketogenic diet is compared with a more flexible and balanced diet of equal calories, the net weight loss is the same. Remember that thing I mentioned earlier about the overarching importance of total caloric intake?
Trust me, slow and steady fat loss is good fat loss. You’ll preserve more muscle, look and feel much better when you do reach your goal, and you’ll be able to do it following a diet that allows you to eat like a normal person.
Claim #4: Sugar makes you fat, not fat.
Sugar can certainly make you fat… if you over-consume it (which I realize many people do) and it puts you in a larger caloric surplus. Funny enough, so does fat. You could also make the argument that fat is more efficient at doing this, as it packs 9 calories per gram compared to 4 calories per gram in carbohydrate.
As for those who fear monger insulin levels – there’s an increasing amount of research showing that some protein sources produce just as much of an insulin response as carbohydrate. Anyway, short-term spikes in insulin still has no overriding effect on overall calorie consumption.
And the notion that sugar is converted to fat more easily than fat – I really have no answer to this other than to use common sense.
Claim #5: Eating more fat makes you lose fat.
Uh… back to the whole common sense thing.
Adding loads of calories through fats probably isn’t going to be the best choice for trying to get lean. I don’t care if they’re from oils, avocados, coconuts, or something you put in your coffee to make it “bulletproof.”
Claim #6: Cutting carbohydrates makes your brain function better.
I continue to hear this more and more and quite frankly I can’t wrap my head around it from a logical sense.
We’ve known for quite some time that the brain prefers to run on glucose… then again, this claim is more of a subjective report, so you just get what you hear.
Anecdotally, I’ve tried some carb-cycling diets in the past and all I could ever focus on during low-carb days was how badly I just wanted a granola bar.
Claim #7: Humans were never meant to eat carbs anyway.
In all fairness, our physiology technically would allow us to forego carbohydrates forever and still adapt and survive, which can’t be said for protein or fat.
However, we literally have an enzyme present in our saliva that starts to break down carbohydrate as soon as we put it in our mouths.
I’ll leave that one at that.
Claim #8: You should cut out fruits because of all the sugar they contain. They actually just make you fat.
Aside from all the vitamins and nutrients that all fruit contains, how many calories per serving do you think you’re getting from a piece of fruit compared to anything else you eat during the day?
I’ve been on this planet for a quarter of a century and so far I’ve never met anyone who got fat from eating too much fruit. The overwhelming odds are that you probably haven’t either.
But if you want to go ahead and demonize apples or whatever else happens to contain fructose, go ahead. It’s likely much easier to avoid those and justify eating more bacon.
To Summarize…
I have nothing personal against most keto diet practitioners. What I do have a bit of an issue with though is the people selling it as a magic diet and using it to demonize certain foods. I think it has become too big of an outlet for the use fear and metaphorical snake oil in order for some people in the fitness industry to make money as well as a name for themselves.
In the cases the keto diet does work for fat loss, I think you could mostly chalk it up to the automatic decrease in total calories. If someone found it to be a viable and sustainable way to lose fat, then I’m all for it. I just don’t see it as a realistically sustainable way to eat for most people. Additionally, I wouldn’t recommend the keto diet to athletes or anyone serious about increasing or maintaining their muscle mass.
Keep in mind that NO diet works on magic and fairy dust and most people are better off developing a series of habits, like tracking calories and macronutrients, than they are struggling to adhere to a diet that doesn’t allow them to eat over half they things they used to eat.
We know through a lot of research and trial and error that you can be fairly flexible with what you eat and still lose body fat effectively, and we’ve known it for some time now. People have been able to lose fat while eating carbs for, well… ever.
It’s easy to get swept up in the current craze or pay attention to dramatic claims. After all, they question the solidified data, which is an exciting concept to most of us. The bottom line is to exercise caution when these things do appear, do your research, and remember that niche pseudoscientific claims are often just just, no matter how loud they seem to be.
Feel free to comment with any questions or thoughts; you can also contact me directly at strengthscrolls@gmail.com
Thanks for reading!
Strength Scrolls 