I actually think keto is the most popular fat loss diet ever.
Without a doubt the most puzzling diet phenomenon. Like, would you be surprised after years of blaming carbs for the world’s increasing waist line we’d decide if low carb didn’t work, “maybe, just maybe, really, really low carb would”.
Or is it right?
Every day I talk to people who have tried it or have friends who are; leading them to ask questions about it.
A ketogenic diet and Weight Watchers are the two most common answers to “what have you tried before” when I speak with an incoming client.
So what gives?
Some claim metabolic magic. They say you’ll lose fat this way better than any other.
Others? Feeling more full. Maybe increased energy. And some pretty damn credible people talk about its positive effects on seizures, Alzheimer’s and cancer.
Certain cancers, at least.
So we’re gonna take a look at this stuff and get some answers.
I fully admit going into it, and you’ll know this if you’ve followed me: I’m not a fan. As you read this, you’ll see my opinions sprinkled in as well.
I also want you to know I tried to look for evidence good enough to change what I think.
This article wasn’t written as as a means for me to push my opinion, I took it as an opportunity to dig into what the science says. To educate myself further and learn a thing or two.
And I did.
What Is The Ketogenic Diet?
Without getting technical on you, it’s a no carb diet.
Or pretty close. Probably looking at 20-50 grams of carbs per day, tops, to get into ketosis: the fat-burning state that the keto diet promises to put you in.
And when carbs are that low, your body needs a new source to drive the body’s energy. So in this case, it switches to using fat (don’t get too excited) and ketones (made from fats).
Some tissues — one of them being the brain — don’t use fat well to produce energy, so the body produces ketones. Researchers would call this a survival mechanism we can use through periods of very low food supply. Without carb sources, we have certain organs that deal much better with ketones vs fat.
“Wait, what about the part where the body switches to burning fat instead of carbs?”
Figured you’d ask.
Although the idea using fat for energy leading to actual fat loss is incredibly intuitive, nutritional researcher Brad Dieter points out using more fatty acids for fuel doesn’t necessarily mean more fat loss.
And if you haven’t been hiding under a rock for the last 10-20 years what Dieter says makes a ton of sense. I’ll just say it this way:
If you believe eating fat doesn’t make you fat, you should believe using fat for fuel doesn’t mean you’re losing body fat.
Understanding this undermines a central argument pushed by proponents of keto, intermittent fasting, fasted cardio, and probably some other trendy fitness stuff. The idea we can make the body use fat for fuel instead of carbs isn’t interesting from a fat loss perspective.
You’re trying to lose body fat, not body carbs. And body fat is excess energy storage.
Back to ketones…
Ketones are essentially a work around fuel source for the body when carbs are low. The question is, in terms of things like fat loss, or certain health issues, is this alternative energy source like the normal gas for your car, or is it premium stuff?
One thing seems certain among those in the know when it comes to the ketogenic diet is ketones facilitate our livelihood when food supply is low.
This doesn’t mean it’s a bad thing, or a good thing, it just means if you ever spend more than a few days in the arctic without Whole Foods, Wal-Mart or a gas station nearby, ketone production could make it easier to stay alive.
Or just have enough energy to find a place to get food.
How Do You Get Into Ketosis?
As a general rule it’s suggested to keep a carbohydrate intake to less than 50 grams a day; some say less than 20.
So all that means is a strong percentage of those you hear saying they’re on keto probably aren’t. “Modified keto” isn’t actually a thing.
Confirming whether you’re in ketosis or not can be done in a few ways:
- Urine strips (convenient, cheap, and can be unreliable)
- Breath Ketone Analyzer (easy, less accurate than blood)
- Blood Ketone Meters (most expensive, more accurate, gotta prick yourself)
A 0.5mM level of ketones in the body is considered baseline for nutritional ketosis.
What Can Keto Supposedly Do That Other Diets Don’t?
Considering the ketogenic diet may be the most popular diet of all time, there must be a reason or two.
Improved fat loss, better fullness and performance; to, well, treating things like Alzheimers, epilepsy, and even cancer.
And you are urged emphatically by this writer to seek a doctor’s opinion when it comes to nutritional intervention and treating medical conditions (in case you take anything said in here out of context)
On top of these, I’m sure there are others. You’ll often hear people go from eating poorly to “insert any diet here” and name off all kinds of special benefits they attach to this diet — clearer mind, skin, confidence, better cognition — however these are benefits you can expect when you get away from processed foods and eat more vegetables, fruits and lean proteins.
Weight loss, lower hunger, craving control, more energy, better mood – this all tends to come with eating healthier however you do it.
So, again, what gives? Lets find out.
Keto For Weight Loss (or fat loss)
The ketogenic diet has been around forever, but its mainstream popularity– and popularity barely does it justice–is all about the claims of its fat loss benefits; the word of mouth phenomenon, in my opinion, having everything to do with a rapid 4-6 pound drop on the scale seen in the first week.
I honestly think it wouldn’t have large scale popularity for weight loss without this.
Basically, you can expect a significant drop in bodyweight within the first week. You might think that losing 4-6 pounds in a week sounds awesome. It totally does. However, it’s not all fat you’d be losing. A lot of that weight is water weight, which can come right back as soon as you reintroduce carbs.
The water weight drop wasn’t my opinion, by the way, I was talking about my opinion when it comes to why keto is popular. Your mom may have never stepped foot in a gym and hasn’t tried a diet ever, but she knows keto:
“Ha, that diet people can’t even eat bread or cake or whatever lol”.
And it’s become so popular she may even try it.
If she hasn’t already.
Does Keto Burn Fat Better?
The idea here is that if you can take away carbs you force the body to use fat for fuel while the body creates its own energy source (ketones). From there, you put your body into a state where it’s burning more fat, while also not starving for food because it’s making its own energy off fat (the ketones).
Keto or not, proponents of low carb dieting promote the idea that lower insulin levels (simplistically known as a storage hormone) takes the body away from a fat storage environment to one that uses fat for fuel.
This is technically right, mind you.
But it isn’t how fat loss works.
How Does Weight Loss Work?
Fat loss works almost entirely by creating a calorie deficit. Calories are a unit of energy and your body is basically an energy source. It can take energy off itself if it needs.
Body fat is stored energy.
It can be used later when it doesn’t have enough food as well.
It’s like storing stuff in your home. Storing stuff is useful, but after a while you’re a hoarder and it’s a hard problem.
Sounds crazy, but don’t worry, when you burn more calories than you eat and drink your body typically chooses body fat to make up the difference. The less fat you have, the more you need strength training and higher protein intakes to keep the muscle you have.
Strength training, by the way, is much more important than the protein. But they both help. If you need to learn how to make your own strength training programs, go HERE.
So it’s not a decision between burning body fat or burning body carbs. The difference between eating carbs or fats isn’t an increase in body fat. Body fat is a calorie thing.
No calorie deficit, no fat loss. Keto or not.
Does The Ketogenic Diet Work Better If You’re In A Calorie Deficit Though?
It’s still a good question. Because you can be in a calorie deficit and in ketosis. And you can be in a calorie deficit without ketosis.
All I’ve said so far is that a calorie deficit must be present to lose fat. But what about being in a ketosis while in a calorie deficit? Does it work better?
Several studies have looked at ketogenic diets vs non-ketogenic diets. And many diets have compared diets with equal calories with different configurations of macronutrients (more/less carbs and fats).
The consensus among these studies is that there is no advantage (1)(2)(3) . Interestingly enough, the study by Hall showed fat loss slowing once subjects started using fat for fuel with a lower insulin level(3).
Not only does this not appear to be the case, there is indication that muscle is more easily lost on keto (3). Just keep in mind these subjects weren’t training (or exercising at all). No reason to think results get better when you combine very low carb with strength training either.
By the way, the Hall study in particular is even more interesting because it was funded in part by a group called NuSi. A now defunct organization led by Gary Taubes, a best-selling low carb dieting author, and Peter Attia, a popular backer of the ketogenic diet.
NuSi was accused of cherry-picking data to support its low carb bias.
So far Gary Taubes has honestly not changed his mind in the face of clear scientific evidence.
Although it’s 100% possible to lose fat on the ketogenic diet, there is nothing to support it works better. If anything, it appears it may work less, albeit insignificantly less. And this is without even considering an ability to adhere as these studies controlled intake closely.
Can You Stick To Keto?
Sticking to any plan is obviously important.
It’s actually the most important thing. Like having a map to get somewhere doesn’t matter if you don’t follow the right route.
If you set a plan for x calories a day and than you end up with x calories + 400 calories a day, you may not be getting anywhere.
Sounds obvious, but science has shown us this doesn’t just happen sometimes, it’s pretty common.
If you’ve used a calorie counting app, or a calorie calculator and didn’t get results, there’s a really good chance you didn’t follow it closely enough.
So the issues with keto are:
- This isn’t a typical diet, it’s highly restrictive.
- If you’re looking for the benefits of keto, there isn’t really any flexibility. You’re either in ketosis or not.
- Pizza tastes good and makes people happy. It probably makes you happy. And reasonable quantities doesn’t stop weight loss, but it will stop ketosis (which, again, has no benefits for fat loss anyways).
Number 1 is pretty straight forward. Do I really need research for you to believe a diet involving no pizza, no muffins, no cookies, no beer, no wine, and no cake is harder to stick to?
If you want to argue the straightforward rules make it easier, go for it.
That’s fair, I guess.
Just let me know how it’s going in 4 weeks, then 8 weeks, then 12 weeks. Long enough to weed most people out.
What about number #2?
Look, you can’t half-ass being in ketosis. You can’t sort of be on keto. You’re in ketosis or you aren’t; and although there’s argument in terms of what you actually have to do to be in ketosis, lets get one thing really clear: you can’t be eating carbs freely, at all, on a week to week basis.
My Own Personal Gripe
The topic of keto is everywhere in fitness and weight loss. And the safest advice to give seems to be: “well, if you don’t eat carbs and don’t like them, well then keto might work for you”.
Sorry for the 1 percenter that reads this but carbohydrates are as normal to life as coffee is to your morning. Even if someone has a propensity for a low carbohydrate diet (totally possible), why would there be a suggestion to that person to stay away from carbs entirely for zero extra benefits? Again, when fat loss is the concern.
I suggest carbs. And if you only eat some, I wouldn’t suggest there’s any good reason to shave 50-100 a day down to sub 50.
I’ve dropped about 13 pounds after a lengthy period adding some weight back due to other priorities eating about 180-250 grams of carbs daily. Believe it or not, I could do it eating 300-400, too. It’d just suck because we kinda need those fats and proteins to feel our best.
Does Keto Help With Hunger?
Although I don’t think it’s everyone’s problem when it comes to weight loss, fullness and hunger are factors that obviously come into play. And their does appear to be some evidence for keto’s ability to lower hunger.
A team of researchers looked at a collection of studies on the subject of hunger, keto and very low calorie diets finding evidence the ketogenic diet (or even just low carb diets) will prevent a rise in hunger as calories are lowered.
And maybe an indication it will blunt hunger further than where it was at a normal calorie level. Oddly, less calories, less hunger.
We can’t be too certain ketosis will give you a greater benefit to suppressing appetite, but it’s been shown to a point it’s a reasonable expectation. And researchers of this large study noted more work would need to be done on testing hunger at different levels of ketosis.
Steak and eggs IS very filling, by the way.
This study by Johnstone did show a 294/day reduction in calories with protein equated between two groups — important because protein is by far more filling than carbs and fats.
Because anyone in their right mind knows being full while trying to lose weight may not matter if eating eggs, steak and avocados all the time doesn’t work with your life at all.
Still, useful to know.
What I’ve always said is if you have a desire to go a hard month, get some weight off and gather some momentum; while likely adjusting tastes and cravings to a blander diet, keto may make sense. Or even just something close to keto or strict paleo, even.
Again, not because of their magical benefits but because of how basic and naturally focused the food selections are.
Problem is I just don’t think many people start keto with an exit strategy.
The Ketogenic Diet And Health
My chance to show you I don’t have my blinders on when it comes to keto. I make it abundantly clear, especially for fat loss, I’m not a fan of mainstream diets. To me, they provide simple rules upfront for greater challenges to adherence later on.
In most cases, they’re just unrealistic over the long haul for most people.
But keto for health is interesting. I’ll say this up front:
I’m not a doctor or registered dietitian and don’t treat anything or guide your friend and their medical issue with anything you read here.
I leaned a lot on Dom D’Agostino, arguably the world’s most renowned ketogenic diet researcher, for a lot of this. If you’re not sure, you can assume any strong opinion or statement here is from him.
For the record, he believes sticking to a low carb diet leads to the discipline needed to sustain a calorie deficit. Not to extract words from D’Agostino’s mouth, but it does sound like he’s saying keto itself isn’t better fat loss directly. His interest in the keto diet doesn’t appear to be about fat loss benefits per se.
Just pointing that out.
D’Agostino does talk about a very well-documented reliance on keto when drug therapy failed for seizures citing a “neuroprotective” effect that can also help with brain injuries. He was very strong saying it’s a “very effective anti-seizure strategy”.
And to be sure, although it’s easy to see a keto researcher as a potential kool-aid drinker (sugar-free, of course), it is well-known in the scientific community the ketogenic diet can help with seizures.
So, if you suffer from seizures, talk to your doctor about it.
D’Agostino claims about 20-30% of people with Alzheimer’s see improvements in Alzheimer’s related symptoms when put on the ketogenic diet.
With a propensity to use ketones very well, the brain does appear to find some therapeutic benefits from this diet. Can it help prevent problems? I don’t think we know.
Another more recent study had 15 participants stick to a ketogenic diet measured by urine nightly. With the help of a caregiver, 10 people finished the study. Cognitive results improved significantly in 9 of 10 and the one who did not actually came off Alzheimer’s related medications.
However, before you go around telling people the ketogenic diet helps Alzheimer’s it’s important you know there was no control group to compare to; and reasons for cognitive improvement can reasonably attributes to things like excitement or improved diet in general as a result of being in the study.
This was research that just creates more questions leading to better research.
Emotional Health And Motivation
Although I don’t go through this in an attempt to suggest low carb dieting means you’re gonna feel less motivated, energetic and driven it has been shown scientifically (1). This is also somewhat predictable, especially if you’re active and train intensely.
Active people tend to feel better with carbohydrates.
Susan Kleiner, PhD, goes as far to say “In most people, a diet of less than 40% carbohydrates is literally depressing,” she said. “If you have a tendency towards depression, a low carb diet raises your risk”
Those numbers seem a little high in my eyes, but I don’t think it means to completely ignore the potential health ramifications of going low carb or keto — especially if you’re highly active and exercise intensely, or for long duration, on a regular basis.
Basically, the more active you are, the more like you are to need the carbs. But that doesn’t mean carbs are making you fat if you’re not active. You probably just don’t need them and can focus at least on baseline nutrition more with fruits and vegetables.
Athletic Performance And The Ketogenic Diet
Speaking of Kleiner, she does point to the massive pile of research supporting the higher carb intakes for better athletic performance (here, here, here, and here); and a comparably massive pile of research showing athletic performance decline in a low carb or ketogenic state.
I will add, some people likely do fine and this doesn’t cover every type of athletic and fitness style. A study out of New Zealand does show impairments to endurance activities (5). But if you’re a typical person doing a little cardio or strength training, you aren’t likely to notice a major difference.
Is The Ketogenic Diet Safe Long-Term?
The jury’s still out.
If you were looking for something conclusive here, sorry, doesn’t appear like we’ve got much.
There aren’t many people out there who want to opt-in to be studied long-term. The Inuit, however, do eat a diet we’d have to look at as ketogenic. Life expectancy of those in the Inuit regions of Canada shows up at 67 and 71 for men and women, respectively.
It’d be foolish to attribute this 10 or so years less of life expectancy to diet though. Like, very foolish considering they live in the Arctic and have less access to healthcare.
Alan Aragon has pointed to some observational research that shows certain heart and vascular related risks with epileptic patients on the ketogenic diet long-term. You should always note observational research is the weakest type of research, but another study has shown risks of greater inflammation from it as well (1).
This is not strong enough to suggest the ketogenic diet is a health risk long-term.
Should You Do The Ketogenic Diet? My Take..
For whatever it’s worth, I often revert to common sense when it comes to food. Usually, it’s a good way to play it. And for me, any diet that proposes less fruits and vegetables, and other foods that have been freely available on this planet forever, is questionable.
Especially when it comes to generally healthy people looking for a quality diet that helps with fat loss or adding muscle.
“Yeah like this ketogenic diet, you just eat less carbs. So like, less fruits and vegetables compared to the amount we relied on to exist as humans on this planet up until this point.”
It’s just weird to me. Even if it does appear to have some clinical use.
Go for it, if you want. But aside from seizures and last ditch holistic efforts to help with certain cancers (see your doctor), I see nothing but downsides even when considering possible upsides with regards to controlling hunger.
Unrealistically restrictive, and for what benefit?
Try it if you want, but first, maybe consider why you’re doing it. And that if it’s about fat loss, you’ll probably do better with carbs.
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1. Johnston, C, et al. (2006). Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets. American Journal Of Clinical Nutrition. May;83(5):1055-61.
2. Luscombe March, N, et al. (2005). Carbohydrate-restricted diets high in either monounsaturated fat or protein are equally effective at promoting fat loss and improving blood lipids. American Journal Of Clinical Nutrition. Apr;81(4):762-7
3. Hall KD, et al. Energy expenditure and body composition changes after an isocaloric ketogenic diet in overweight and obese men. American Journal Of Clinical Nutrition. 2016 Jul 6
4. Zinn, C, et al. (2017). Ketogenic diet benefits body composition and well-being but not performance in a pilot case study of New Zealand endurance athletes. Journal of the International Society of Sports Nutrition. 201714:22