Another important difference between endogenous and exogenous BOHB is that most synthetic BOHB used in dietary supplements is a mixture of the two ‘D’ and ‘L’ isomers, whereas endogenously produced BOHB consists of just the D-isomer. Metabolically, the two isomers are very different, and current published information indicates that most of the energy and signaling benefits of BOHB derive from the D-form. This is potentially problematic because the L-isomers are not metabolized via the same chemical pathways as the D-forms (Lincoln 1987, Stubbs 2017), and it remains unclear whether humans can convert the L-form to the D-form.
When you are in a state of ketosis, the body turns fatty acids into ketones - these appear as beta-hydroxybutyrate in the blood. Measuring blood ketones is regarded as the gold standard and most accurate way to track ketone levels. Testing this way can be expensive, its can cost up to $3 a strip, so if you're testing multiple times a day it can get pricey.
However, with the ketone esters, the effects are nearly immediate, and my entire body was humming throughout the entire day, but not in a jittery way. I was full of mental and physical energy that lasted without any sort of crash (it was a gradual taper). During my cognitive tests, things felt almost effortless as I played the various games. After my experiment was complete I continued writing code for several hours, then went to the gym to work out. I did forget to each lunch though, so there must be some suppressive effect on appetite.
Also known as the carb flu, the keto flu is commonly experienced by people who are transitioning to a Ketogenic diet. “Keto flu” is not actually flu but mimics the experience of flu with very similar symptoms. It can happen when someone who has become accustomed to relying primarily on carbohydrates as fuel removes them from their diet. Whilst this is a necessary step towards adjusting from being a sugar-burner to a fat-burner, the sudden change can trigger some unpleasant symptoms, much like withdrawing from an addictive substance. Keto flu symptoms can include drowsiness, nausea, dizziness, achy muscles, mental fogginess and an irritable mood. The good news though, is that most of these experiences relate to dehydration and electrolyte depletion, and so are easily prevented or managed. Simply adding a ¼ - ½ teaspoon of a high quality sea salt or sodium/potassium powder to a glass of water works wonders; however you may still require a separate magnesium supplement; particularly if you are prone to muscle cramps or restless legs. Another popular way to manage your electrolytes is via a good quality bone broth powder. Finally, since BHB’s are normally delivered via a mineral salt base*, keto flu symptoms are easily prevented or reduced by using an exogenous ketone supplement powder.
Task switching is the process of adapting to changing circumstances (switching from one goal to another). Two cards are shown one above the other, and a combination of letter and a number (i.e., “A4”) will appear on one of the two cards. If it appears on top, the task is to indicate whether the number is an even number, and if on the bottom the task is to indicate whether the letter is a vowel.

One thing to remember here is that even if your calculated daily ‘keto approved’ protein allowance is (let’s say) 150g, that doesn’t mean you can eat 150g in one meal and still be in ketosis. You may find that you can’t eat more than 40g of protein at a time, otherwise you will drop out of ketosis. OR, you may find you can eat 50g of protein but you need a LOT of fat. Whereas a small serve of 15g of protein without fat might knock you out of ketosis. 


Ketosis supplements made in poor quality, have proven to lead to side-effects such as constipation and increased levels of cholesterol and triglycerides in men, and women may also experience amenorrhea or other disruptions to the menstrual cycle. This is why it is really important to know what combination of compounds you are consuming, particularly while you are on this very strict diet because the wrong balance can really mess with you in the long term and won't give you the high performance that you are looking for. 
Ketosis is a unique metabolic state where your body burns fat instead of glucose for fuel. Glucose is a simple sugar molecule derived from carbohydrates. Your body prefers using glucose to using fat and protein to make energy. This is because glucose it is easy to burn as it doesn't require much energy. On the other hand, your body uses fat and protein to build and repair tissue and make hormones.
Hybrid strategy: A hybrid strategy is to follow a low-carb/high-fat ketogenic diet to induce nutritional ketosis and use ketone supplements strategically. Supplements like Ketone salts or MCT oil can help ease the transition into ketosis, they can be an effective tool when we are knocked out of nutritional ketosis and they can help push ketone levels higher in the body for added benefit.

Supplemental BHB’s are ideal for people new to the ketogenic way of eating. The changes that happen in your brain and body when adapting to a VLC diet are both immediate and profound. For example, our kidney’s start processing minerals salts much more efficiently. Ironically, after years of being advised to decrease our intake of salt (sodium), it turns out that for people transitioning away from the Standard American Diet (SAD diet) towards a lower carb or ketogenic diet there is actually a need to increase dietary mineral salts such as potassium, sodium, magnesium and calcium. During the process of becoming keto-adapted, it is very important to increase your intake of these essential minerals, in order to prevent the onset of unpleasant symptoms (known as “keto flu”).


This research is a good reminder to discuss with your doctor before taking any supplements. Given the widespread use of calcium supplements, more research is required before any final conclusions can be drawn. Several ketone companies have tried to avoid the large sodium loads but instead relied on a bump in the calcium content from the BHB ketone salts, seemingly without consideration for the aforementioned results. Calcium BHB will likely absorb slower compared to sodium BHB due to digestion and absorption kinetics.  For those looking to optimize brain uptake of ketones, this probably isn’t the best strategy (as uptake is directly proportional to the levels in the blood).   Be cautious of supplements running from the sodium and chasing the calcium BHB instead, and make sure you factor that into your overall daily needs.

The body will start making ketones when either we go extended periods without food, or we restrict the one dietary component that stops ketone formation – this being carbohydrates and also minimising protein intake as this also can halt ketone. In turn, your primary source of food is fat, with very little carbohydrate and a small amount of protein.”


I just read your comment and was wondering the same thing. I can see how exogenous ketones can be a great energy boost to people on the ketogenic diet, but I don’t see how they can speed fat loss. Keto OS claims you can eat higher carbs and still see the benefits of ketosis. I don’t see how that is possible. the whole point of weight loss through ketosis is the breaking down of your own fat to create energy. I don’t see how exogenous energy will increase natural fat breakdown. I wish I could get a straight answer to this from somebody.
Fortunately, you don’t need to be a dietary math savant to cash in on these rewards because the supplement eggheads took the liberty of creating exogenous ketones, which act as direct substitutes to the ones your body creates. Unlike other fat burners that give you the skits jitters, these are actually helping exercisers reach new personal bests while getting leaner, and are totally legal. Here’s what you need to know to get a slice of the action safely.

Your body uses the energy source that is the easiest to use, in our case this is glucose. Glucose is just a type of sugar. As our body cannot store glucose as such it stores the extra glucose in form of glycogen that is stored in our liver and muscles. To initiate production of ketones in your body as fast as possible you must deplete your body of glycogen reserves. The best way to do this is a simple 24 hours fast. This will deplete your glycogen stores as fast as possible. If you don’t over eat for dinner or you even skip it all together you will already wake up in state of mild ketosis the next morning due to the overnight fast. Here are also described some signs that you are in Ketosis already.
Ketoacidosis is driven by a lack of insulin in the body.  Without insulin, blood sugar rises to high levels and stored fat streams from fat cells.  This excess amount of fat metabolism results in the production of abnormal quantities of ketones. The combination of high blood sugar and high ketone levels can upset the normal acid/base balance in the blood and become dangerous.  In order to reach a state of ketoacidosis, insulin levels must be so low that the regulation of blood sugar and fatty acid flow is impaired.

Even though endurance athletes can train in a carb depleted state, they will generally consume carbohydrates in the lead up to a race (the athlete is seeking to increase the ability to run off fats by training in a carb depleted state, then benefiting from both fats AND carbs come race day). Likewise, with the brain, even though the brain can function off ketones, does it mean it’s the best state for brain function?


A typical serving of racemic ketone salts contains around 12g of beta hydroxybutyrate, of which only half is the D- form (6g). Compared to the 40g ketone esters I consumed (which are 100% D- form), I would need to consume somewhere around seven to nine packets of ketone salts to get the same amount of D-β-hydroxybutyrate (some D- form is wasted burning of the L- form), along with the huge amount of salts contained and more than a gallon of water (since the powders must be mixed). Even if one could consume that amount of ketone salts, they will probably suffer from what people often refer as “disaster pants” (aka diarrhea) due to the amount of salt consumed.
Ketone Esters: These are not normally found in the body, but exogenous ketone esters convert into BHB once it is in the body. They are also synthetically (lab) made compounds that link an alcohol to a ketone body, which can then be metabolized by the liver into a ketone. They are like ketone salts on steroids as they have 5-10 time more BHB per serving/maximum daily intake than ketone salts. To date, pure ketone esters have been very expensive to produce and have only been available to researchers, elite athletes (Tour de France cyclists), and the US Department of Defense (people have spent more than $20,000 to have an independent lab produce a single serving!).
Other ingredients: Many of the supplements contain large amounts of caffeine – the supplement we tested from Prüvit contains the same amount as a 16 oz cup of coffee! Some supplements also contain malic acid, which is “known for its ability to increase energy and tolerance to exercise”. This leaves the nagging doubt: if the experiment shows an increase in energy and physical performance, for example, how do we know it is the (expensive) BHB causing the effect and not the (inexpensive) other ingredients?
Weight loss benefits ushered the keto diet into the spotlight. That’s how most people have likely heard about ketones, a fuel source created naturally by the body when burning fat. But more and more research points to diverse applications of ketones in the blood outside of just fat loss, from improved endurance performance to the treatment of medical conditions like epilepsy.
How did I do this? Simple, I went into a full fast and exercised. What prevents you from entering ketosis is all the glycogen stored in your liver and muscles. Your body can use this glycogen instead of ketones to fuel your brain, so until you deplete your stores of glycogen, you won’t be able to enter ketosis. By eating nothing, you are going to tap into the glycogen to fuel your brain because you are eating 0 grams of carbs and will also be using that glycogen to walk around all day.
In addition to the Weir coefficients being potentially off (which impacts EE), the RQ interpretation may be incorrect in the presence of endogenous or exogenous ketones. As a result, the estimation of fat and glucose oxidation may be off (though it’s directionally correct). That said, the current interpretation seems quite plausible—greater fat oxidation when I had to make my ketones; less when I got my ketones for “free.”

Affiliate Disclosure: There are links on this site that can be defined as affiliate links. This means that I may receive a small commission (at no cost to you) if you purchase something when clicking on the links that take you through to a different website. By clicking on the links, you are in no way obligated to buy.

Medical Disclaimer: The material on this site is provided for informational purposes only and is not medical advice. Always consult your physician before beginning any diet or exercise program.

Copyright © lowcarbtransformation.com

×