Posted in Diet Reviews.

I’ve gotten a crazy number of requests do this Pruvit Keto/OS review. Keto/OS is a new exogenous ketone supplement that people are using to lose weight, among other things.

I found very little in terms of research on exogenous ketones in humans. Exogenous ketones have been studied a bit in rats, and no one has studied them in terms of weight loss in people or in rodents. The product Keto/OS has no research behind it either, so I decided to bite the bullet and put myself on it for a week to see what would happen.

I hate using small studies as proof for anything, but in this case, I had no choice. It was totally an n=1.

I also hate drinking disgusting things, but again, in this case I had no choice. Sigh.

Before I talk about how that all went, let’s chat about ketones and how they work in your body.

What are ketones?

Ketones are the byproduct of fat metabolism. When you deprive your body of it’s favorite source of energy – glucose – it starts burning your fat for fuel. That’s the premise of the ketogenic diet: burn fat, use the ketones that result as energy.

Staying on the ketogenic diet is tough for most people, but it can be done, and for most healthy people, it’s probably not harmful.

Check with your doctor or dietitian before starting any diet.

Read my ketogenic diet review here.

The issue with ketosis for weight loss is that when you break ketosis, the weight will probably come back on. If you’re a person who lives to eat and not eats to live, it might not be the best weight-loss option for you.

Because a ketogenic diet is so difficult for most people to maintain, Pruvit is marketing Keto/OS by saying that you can eat a normal diet, drink Keto/OS, still go into ketosis, and lose weight when your body burns fat for energy from being in ‘ketosis’ from the supplement.

The research and claims

The Pruvit website lists quite a bit of research, but unfortunately it’s all on ketogenic diets, not on their actual product or exogenous ketones. And smartly, Pruvit has a disclaimer on their research page that states:

Under no circumstance is the information contained within such third party research to be used or considered as a direct, or indirect study of any Prüvit product.

It’s almost as if they’ve read my reviews of other products where I call companies out for pretending that the research is about their product when it’s not! Great job, Pruvit!

Pruvit claims that Keto/OS increases focus, energy, fat loss, and strength, and helps with sleep and mood. Sounds like a miracle worker!

Regardless of what Pruvit claims, my questions are: does Keto/OS work just like a ketogenic diet, or are you just drinking (and peeing out) ketones and consuming extra calories from the supplement while you do it? 

Are exogenous (meaning: from outside the body) ketones treated the same by the body as endogenous (meaning: from inside the body, or what you body makes itself as the result of a ketogenic diet) ones? Can you really consume ketones and eat carbs and still be in ketosis?

And just because you’re peeing out ketones (measured by Ketostix), does that mean you’re actually in ketosis? The definition of ketosis is when you have ketones in your blood, not in your urine. 

Pruvit says that a urine or blood test (but face it – why test your blood when you can just pee on a Ketostick) is how you test for ketosis while on their product.

Because ketosis is a complicated animal, I consulted with a leading expert in the field (they wanted to remain anonymous), who gave me this answer to my question above:

Think of (ketones) as just another energy source. It will last a couple of hours in the body and then be either used as fuel, stored or eliminated. The true state of ketosis involves metabolic changes that include the ramping up of many fat burning enzymatic pathways as well as an increase in the number of mitochondria in the cells. This process can take a number of weeks and is referred to as fat adaptation or keto adaptation. Unfortunately, this metabolic adaptation is not something that can be bottled or made into a powder or pill. 

I also had a call with a Pruvit Ambassador to get a good, balanced view of the product and see how it ‘changed his life’. He said that Pruvit is doing research on the product that will be available ‘imminently’. He was adamant that the supplement put him into ketosis, and he uses it as an adjunct to an ‘80% ketogenic diet’. “I like wine”, he joked. Hey – I hear you! He told me:

If I were to explain it in a few words, I would say that Keto//OS is the world’s first commercially available exogenous Ketone product and it works in the human body 100% of the time.  Oh, and it makes you feel awesome and the Community is about making people Better. 

Seeing as he has clearly drunk the ‘keto kool aid’, I was raring to see for myself what would happen when I tried it.

The Keto/OS diaries

I managed to secure some Keto/OS from someone in my neighborhood, which was great, because it’s super expensive. I definitely didn’t want to spend over $200 CAD for a 30-packet order when I wasn’t sure how I’d react to it.

The dosage of Keto/OS is 1-2 packets a day. Seeing as I already eat a low-carb diet on my own (not because I’m afraid of carbs, but just because I prefer to eat a lot of vegetables), I figured I’d use one packet a day and see what happened.

Day 1

I chose to start my trial on a morning that I was seeing clients. Maybe not the best choice, since I wasn’t entirely sure that I was going to drink it and not suddenly fall to the floor clutching my throat or barf or something embarrassing like that. I skipped my daily coffee because I really wanted to see how the Keto/OS was going to affect me. I weighed myself and was ready to go. Let’s burn some fat! I thought.

My first client of the day watched me sympathetically as I downed the milky white, cloyingly sweet orange-flavored drink, wincing with every gulp. The sweetness was out of control – maybe to hide the flavour of the ketones?

Interestingly, the orange flavour of Keto/OS has 110 calories; the chocolate flavor, only 50.

Anyhow, 30 minutes later, I felt fine. I started to get a headache, which never left me the entire day, but otherwise? I felt normal. I felt no effects in terms of appetite suppression – in fact, after a huge Whole Foods salad bar lunch, I was actually craving cookies. What the hell!?

About 5 hours later, I tested my pee for ketones. Negative.

I was curious: if the product claims that you don’t have to change your diet in order for it to work, but by a matter of hours later the ketones are gone from your body, and you’re not taking packets of this stuff all day and all night, then how does it work, exactly? Isn’t the main idea that it puts you into ketosis all day so you burn fat without the work of a ketogenic diet? 

The Pruvit Ambassador I spoke to told me in response to this question that I’d have to take 2-3 packets a day if this is the case. That sounds really expensive, really gross, and how would that work exactly? 3 packets x 4 hours = 12 hours. So the remaining 12 hours I wouldn’t be in ‘ketosis’? And if I took 3 packets a day, theoretically that would be 330 extra calories. 

Day 2

This day, I drank the caffeinated chocolate flavor. Again cloyingly sweet and bitter, I gulped it down faster than the day before. One things about exogenous ketones that I think everyone can agree with: they taste vile. Like, really BAD. I literally gagged on the last gulp of them and wondered how I was going to do this every day for the foreseeable future. CRAP.

An hour later, my urine had ‘moderate’ ketones in it, and I was starving, but otherwise I felt completely normal, aside from the fact that my stomach was weirdly bloated like a balloon. Funny enough, I didn’t even feel like I’d consumed any caffeine. The Ambassador did say that the caffeine in the product isn’t for energy, it’s to expedite the body’s reaction to the ketones.

I continued to be starving, even though I had not changed my diet (I’m the sort of person who eats similar food every day). I mean, I was so #$@%@ hungry, I resorted to eating some ratty old cough drops in my purse on my way to a lunch date. I hadn’t worked out in days, so this was not the result of being more active or eating less. I was way hungrier than normal.

Days 3-7

Same same. Basically, I felt completely normal, was somewhat bloated, and by 3-4 hours after consumption, my urine showed only trace ketones. I was starving throughout the day, too: I felt like I was on a weight-gain track, not weight loss. After 7 days, I had swallowed about as many packets of Keto/OS that I could possibly stomach.

The results: 

I really didn’t feel any different on Keto/OS than I do in my normal life, and that’s the truth. I had none of the typical issues that people in ketosis suffer from: no GI distress, no ‘keto-flu’ or exhaustion, no appetite suppression, etc.

Maybe I’m just resistant to ketones? Maybe I’m used to feeling a certain way because on a lot of days, I eat less than my fair share of carbs? But the hunger. The hunger was real.

I asked my expert why I was so hungry. This is what he had to say:

Low carb diets are all about reducing insulin levels which increases fat mobilization from our adipose tissue and ultimately leads to ketone production from the liver. It is now clear that high levels of exogenous ketones increase insulin levels which shut down fat mobilization. Just another example of “more is not better”. This is probably also why you are feeling hungry…insulin goes up, energy substrates in the blood go down…hunger ensues.

So essentially, I wasn’t burning fat at all. I was just increasing my insulin levels and making myself even hungrier, even though Pruvit claims that Keto/OS increases insulin sensitivity.

I had thought that the longer I was on this supplement, the better it would work. But clearly, it appears to have left my system so quickly that it was never going to build up to a therapeutic level (if there is one).

In short:

  • While exogenous ketones may work for you in terms of appetite suppression, they made me ravenous. This may have been because my insulin levels rose in response to the ketones.
  • I experienced none of the benefits that Pruvit claims it offers. I basically felt normal the entire time I was taking it.
  • I was ketone-free, at least according to my urine, within 3-4 hours of taking Keto/OS. Unless you’re planning on drinking the supplement every 4 hours, I would say that you’re probably not going to sustain ketosis – if you are even in ketosis, that’s another thing – throughout the day and night
  • Ketogenic diets have some positive research behind them, but according to my expert, exogenous ketones aren’t the same as the ones your body produces. And this means that they probably don’t work the same way, either. For weight loss I would say they’re probably not efficacious. That being said, everyone defines ‘success’ differently, so it would depend on what you’re looking for. This was only my experience. My expert did say:                                                                        (Exogenous ketones) might be useful in helping people during the first week or two on a ketogenic diet because they will give the brain a readily available energy source and could help to reduce the “keto-flu” symptoms (keep in mind that only about 1/3 of people get these). Secondly, there may be a therapeutic role for ketone supplements in certain medical conditions, including neurodegenerative diseases such as Alzheimers, Parkinsons, ALS etc. The jury is out on both, but it doesn’t reduce the hype and marketing claims.
  • Keto/OS tastes like death, and is extremely expensive. If you want to try it, I’d say try to secure a few packets first before you go all-in.
  • Pruvit states that Keto/OS is safe to give to children. If you’re putting your child on a diet of any sort, it should be supervised, not done by scaling down your dose of exogenous ketones. And don’t put your kid on a diet, okay? Not for weight loss, anyway.

Last but not least: Stop trying to find short cuts in life and especially in weight loss. Haven’t you read enough of my diet reviews to know that they don’t work? Pass.

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