The same question posed in a different way can be, what’s better, getting protein from powder or from a grass-fed steak or wild salmon? Omega-3 from supplements or from a variety of healthy wild fish? Just like with health supplements where you consume an isolated nutrient instead of the whole food where it comes from, if it’s possible to get what you need from whole food or nutrition, then that’s probably the best choice.

There are a couple factors that will make this look much more viable and achievable. For example, if you were to skip breakfast and have your first meal at 12PM, you could eat up until 8PM. This will also mean that dinner needs to be eaten slightly earlier. But let’s not forget about the fact that if we were to combine this with the 6-10 hours of sleep that you would normally have each night, that’ll take up the majority of your fasting period. Obviously, you’re not restricted to these hours, as everyone has a different schedule. Doesn’t sound as bad as you initially thought? Well let’s make it even more enticing! During your fasting hours, and this is extremely helpful during mornings up until you can have your first meal, non-caloric beverages such as tea and coffee can help starve away those hung pangs. Just make sure you’re taking these drinks on it’s own, without any added sugar or milk. There are many variations of intermittent fasting with the most common being 16/8. But depending on your schedule, there are other options advocated such as 20/4, 22/2, and if you’re crazy enough and can eat a full day’s worth of calories in one sitting then there is also OMAD (one meal a day).
Consuming exogenous ketones isn't the same as following a ketogenic diet–the ketones in the blood haven't been naturally produced by the breakdown of fat stores. However, scientists believe many of the health benefits of the keto diet and fasting (aside from weight loss) are triggered by ketones. Therefore, raising ketone levels through either endogenous or exogenous ketosis could help to improve health and performance by:
Over the 28-day experiment, ketone supplements administered daily significantly elevated blood ketone levels without dietary restriction (Fig. 2a, b). Naturally derived ketogenic supplements including MCT (5 g/kg) elicited a significant rapid elevation in blood βHB within 30–60 min that was sustained for 8 h. BMS + MCT (5 g/kg) elicited a significant elevation in blood βHB at 4 h, which was no longer significant at 8 h. BMS (5 g/kg) did not elicit a significant elevation in blood βHB at any time point. For days 14–28, BMS + MCT (10 g/kg) and MCT (10 g/kg) elevated blood βHB levels within 30 min and remained significantly elevated for up to 12 h. We observed a delay in the peak elevation of blood βHB: BMS + MCT peaked at 8 h instead of at 4 h and MCT at 4 h instead of at 1 h. Blood βHB levels in the BMS group did not show significant elevation at any time point, even after dose escalation (Fig. 2a). Synthetically derived ketogenic supplements including KE and BD supplementation rapidly elevated blood βHB within 30 min and was sustained for 8 h. For the rats receiving ketone supplementation in the form of BD or the KE, dosage was kept at 5 g/kg to prevent adverse effects associated with hyperketonemia. The Precision Xtra™ ketone monitoring system measures βHB only; therefore, total blood ketone levels (βHB + AcAc) would be higher than measured. For each of these groups, the blood βHB profile remained consistent following daily ketone supplementation administration over the 4-week duration. (Fig. 2b).

So, now that we've established that purchasing BHB supplements directly from the manufacturer is the way to go. Now, let's talk about which ketogenic product you should be buying in the stores. Well, if you read our review about the different exogenous ketone supplements, you will also know that Perfect Keto is rated #1 on our list which was a pretty close race but it came out on top after all the tests that we've performed on all the different products.
Over four visits, participants (n = 15) consumed 1.6 and 3.2−1 of βHB as KE (141 mg/kg and 282 mg/kg of R-3-hydroxybutyl-R-1,3-hydroxybutyrate) or as KS (KetoForce, KetoSports, USA) sodium and potassium βHB, containing 1.6–3.2 g of each cation), plus 6 g of sweetener containing 19 kCal (4 g of carbohydrate) (Symrise, Holzminden, Germany), diluted to 300 ml using water. Drink blinding was not possible due to unmaskable differences in taste (bitter vs. salty).
But going keto takes work. You have to overhaul your diet, restrict certain classes of foods, and pay close attention to what you eat. People prefer to avoid work if they can. They like shortcuts. Exogenous ketone supplements promise a shortcut—swallow this pill or mix this powder into your water and see your ketones skyrocket without changing the rest of your diet.
Medium-chain-triglycerides are fats that are easily absorbed by the body and provide a number of really powerful health benefits. Fast energy, appetite control for better weight loss, increased ketone levels—you name it. They are also one of the most convenient and flexible, too. Add it to a shake, make a smoothie, or take a spoonful of it straight with some water for a quick, healthy keto boost that lasts all day. If you’re the kind of person that struggles to stick to a diet or eat a lot throughout the day, MCT oils are the perfect keto supplement.
And zero-carb, followed by fasting for two meals, and then followed up by a second zero-carb meal is almost always all you need to get into ketosis fast. By Sunday or Monday morning, after a second night of no carbs, you’ll be in a deep enough ketosis that hunger will crash and your energy will surge to help you transition into your low-carb diet of choice.
The table below shows the same measurements and calculations as the above table, but under the test conditions. You’ll note that BHB is higher at the start and falls more rapidly, as does glucose (for reasons I’ll explain below). HR data are almost identical to the control test, but VO2 and VCO2 are both lower. RQ, however, is slightly higher, implying that the reduction in oxygen consumption was greater than the reduction in carbon dioxide production.
No the main reason to enter ketosis fast is because it is not pleasent to be glycogen depleted and not yet be in the state of ketosis. You feel sleepy, without energy, some people even have headaches or mild flu symptoms. However you look at this it is not pleasant until your body starts producing ketones and you can effectively start using fat as the primary energy source. So you want to breakthrough this period as fast as possible and not be stuck in this middle place for days or even weeks.
If you noticed that you're not getting into ketosis quick enough, chances are you're not eating enough fat. Eating plenty of healthy fat is essential in inducing ketosis. One reason why this is so is that your body makes ketones from fat. The other reason being that fat is highly satiating, so your body won't slow down or start breaking down muscle for fuel.
Full disclosure: after carrying out the background research, I was already, as you might imagine, feeling a little less neutral about these products. You may have noticed a hint of that in part 1 of the 2-part video series we made about the project (watch part 2 at the top of this page!). However, and although this was by no means a controlled scientific study under laboratory conditions, we designed the experiment in a very objective way. The aim was to give the supplements the best possible chance of showing the benefits they are claimed to have.
Exogenous ketones cause the body to rely less on fat as fuel (see Fig 3). Fat takes longer to metabolise for energy than muscle glycogen. This is why fatty acids are not the preferred fuel under heavy exercise. This could be useful for keto-adapted athletes performing high-intensity cardiovascular or strength training.12 This is particularly useful for the Keto-adapted athlete who wants to undergo high-intensity cardiovascular or strength training.
When you start this process, changes in your daily food and drink intake are designed to increase the amount of healthy fats being burned by your liver, which produces and releases more of these endogenous ketones into your blood stream. When breastfeeding, the female body naturally burns more fat to produce the endogenous ketones, which is an infants resource to the nutrients they need for their young minds. As an adult, a lot of us have substituted the goodness of this compound for more sugar fueled energy. However, I'm sure there are many of you that are wondering right now, "does keto work at all and if so how long does ketosis last?" After numerous tests and studies, it has been recognized that it indeed does work and has been proven to have long lasting effects, so you can rest easy and maybe throw away those weight loss pills that claim instant results but don’t seem to do much.
Hi Acadia, just want to clear up a few things you noted in your post: The manufacture of BHB salts involves ionic bonding of an anion (beta-hydroxybutyrate) with a cation (Na+, K+, Ca+, Mg+). At least one of the exogenous ketone products you listed does in fact contain potassium ions. People taking potassium-sparing drugs need to know this and that raises concerns about leaving it off your chart. Some people are genuinely sodium sensitive even to small amounts of salt added to otherwise healthy foods. This can hold true even for those following ketogenic diets. The term you’re looking for… Read more »

Her clients have had similar success. One woman, for instance, has gone from around 170 pounds to 140 pounds since April without making any initial dietary changes. She’s started to gravitate towards more keto foods over time, but still eats her favorite high-carb treats. As for exercise? Her routine consists of a couple of walks each week, Heverly says.

As repeated KE consumption would be required to maintain nutritional ketosis, we investigated the kinetics of drinks in series and of continuous intra-gastric infusion. During starvation, the accumulation of ketones (>4 mM) reportedly inhibited ketone clearance from the blood, however the underlying mechanism is unknown (Hall et al., 1984; Wastney et al., 1984; Balasse and Fery, 1989). In Study 3, βHB uptake and elimination were identical for the second and third KE drinks, suggesting that βHB may have reached a pseudo-steady state should further identical boluses have been given at similar intervals. Furthermore, when the KE was given at a constant rate via a NG tube, blood ketone concentrations remained ~3 mM. Therefore, repeated KE drinks effectively maintain ketosis at the intervals and doses studied here.

One monk, for example, set out to do a 40 day fast with medical supervision while maintaining his daily activities in the monastery. After 36 days, the medical professionals had to step in due to “profound weakness” and low blood pressure when standing. Although the monk fasted for 15 days longer than Ghandi, the medical professionals were able to stop the fast in time so that he could recover.
I (Kim) researched the topic and planned and ran the experiment under the guidance and supervision of Dr. Andreas Eenfeldt, who touched base with me every step of the way to check the experiment design and execution for scientific rigor (to the greatest degree possible) and who has edited this writeup for quality and trustworthiness reasons. I also consulted with other keto experts and researchers to gather feedback both on the experiment design and the results data. They are referenced in the text when this was the case.
Some think so because higher ketone levels imply increased fuel for the brain and heart (that prefer ketones), and increased protection against inflammation and oxidation. But are the health benefits coming from the ketones themselves, or are they coming from the state you have to put your body in to actually produce them? And if you're kicking yourself out of ketosis by ingesting ketones would you still get the same benefits?
The liver is always producing ketones to some small degree and they are always present in the bloodstream. Under normal dietary conditions, ketone concentrations are simply too low to be of any significant benefit. A ketogenic diet and exogenous ketone supplements will increase the amount of ketone in your body. The idea that ketones are “toxic” is ridiculous. Ketones are a normal physiological substance that play many important roles in the human body.
Those of you who have tried this form of weight loss before are probably more than aware of how hard it can be to first get your body to adapt to such a dramatic change in your daily intake of food, let alone without the help of a single exogenous ketone supplement. And the situation isn’t made any easier if you use a poor quality ketosis supplement because the wrong ketone product may actually do you more harm than good.
Most supplements rely on BHB as the source of their exogenous ketone bodies. BHB is converted to acetoacetic acid with a small quantity converted to acetone through a acetoacetate decarboxylase waste pathway. Some of the acetoacetic acid will enter the energy pathway using beta-ketothialase, which converts acetoacetic acid to two Acetyl-CoA molecules (see diagram below2).
So, now that we've established that purchasing BHB supplements directly from the manufacturer is the way to go. Now, let's talk about which ketogenic product you should be buying in the stores. Well, if you read our review about the different exogenous ketone supplements, you will also know that Perfect Keto is rated #1 on our list which was a pretty close race but it came out on top after all the tests that we've performed on all the different products.

Some common short-term effects that some people experience in the early stages of the process are excessive thirst, fatigue and keto constipation. These minor side-effects occur due to a sudden change to a persons diet, but as I said, once your body starts to adjust to the process, you will start to feel normal again, if not better than before you started. We understand that constipation isn't exactly fun, but it's a small price to pay to experience the long-term health benefits. 
Now that you have fasted for quite a long time, you can break your fast at around 4 to 5 pm. Try having some good fat for this purpose, such as coconut oil or MCT oil, butter, or any other healthy fat. MCT oil might come in as a better option in this case since it gets quickly absorbed by the body. It swiftly bypasses the gallbladder and reaches the liver where it is transformed to ketones rapidly.
The way you make an exogenous BHB is by attaching it to some type of other compound (sodium, potassium, calcium, or magnesium) so that your body can process the molecule by cleaving the bond between the salt and the beta hydroxybutyrate. BHB + bound to a salt = BHB salts, which is what most people in the ketosis community call exogenous ketones. There are also things called esters, which are basically unbound BHB molecules. These are really disgusting and cause massive digestive issues, so I like to ignore them until we can produce them in a more appealing way.
A common question is why BHB is the go-to ketone body for exogenous ketone supplements. The likely reason is a combination of its efficient conversion into energy and its ease of formulation. In other words, that it is easier to formulate BHB into a nutritional supplement. And the body efficiently converts BHB to acetoacetic acid, which effectively raises blood ketone levels.
And zero-carb, followed by fasting for two meals, and then followed up by a second zero-carb meal is almost always all you need to get into ketosis fast. By Sunday or Monday morning, after a second night of no carbs, you'll be in a deep enough ketosis that hunger will crash and your energy will surge to help you transition into your low-carb diet of choice.
MCT oil has recently been used to induce nutritional ketosis although it produces dose-dependent gastrointestinal (GI) side effects in humans that limit the potential for its use to significantly elevate ketones (>0.5 mM). Despite these limitations, Azzam and colleagues published a case report in which a 43-year-old-man had a significant decrease in seizure frequency after supplementing his diet with 4 tablespoons of MCT oil twice daily [96]. An attempt to increase his dosage to 5 tablespoons twice daily was halted by severe GI intolerance. Henderson et al. observed that 20 % of patients reported GI side effects with a 20 g dose of ketogenic agent AC-1202 in a double blind trial in mild to moderate Alzheimer’s patients [24]. We visually observed similar gastrointestinal side effects (loose stools) in the rats treated with MCT oil in our study. Rats were closely monitored to avoid dehydration, and gastric motility returned to normal between 12–24 h. Interestingly, the BMS + MCT supplement elevated βHB similarly to MCT oil alone, without causing the adverse gastrointestinal effects seen in MCT-supplemented rats. However, this could be due to the fact in a 10 g/kg dose of BMS + MCT, only 5 g/kg is MCT alone, which is less than the 10 g/kg dose that elicits the GI side effects. This suggests that this novel combination may provide a more useful therapeutic option than MCT oil alone, which is limited in its ability to elevate ketones in humans.
Funding. This work supported by an Industrial DPhil Fellowship to BS from the Royal Commission for the Exhibition of 1851. JM was supported by the EPSRC Doctoral Training Centre and Prize Fellowship; Ref: EP/M508111/1. The funding sources were not involved in the design, conduct or analysis of this study. TΔS Ltd. provided the ketone ester, ΔG®, and NTT DOCOMO Inc. provided the acetone meter for the study.

I began by simply playing all of the games over and over again (each game many dozens of times over the period of a week) to remove any “learning effect.” I then selected two games from each category (for a total of 10 games) and for a period of five days prior to “ketone-day” played each game five times each day. My “before ketones” baseline scores put me in the top 4% of all Lumosity users, so I was already in a good place. But could I improve even more, just one hour after consuming the ketones?
The second ketone ester compound was developed at the University of South Florida. This is a diester of AcAc and BDO. In rodents, this ketone ester raises blood D-BHB to 1-4 mM and blood AcAc to up to 5 mM.19 There is one published study of this ketone ester in humans; results showed a 2% decrease in 31 km cycling time trial performance.16 This may be due to the high rate of side effects of this ester studied. Other factors may have been low levels of BHB (<2 mM), the short, high-intensity time trial used, or the use of AcAc vs. BHB.
2. Shimazu, T., Hirschey, M.D., Newman, J., He, W., Shirakawa, K., Le Moan, N., Grueter, C.A., Lim, H., Saunders, L.R., Stevens, R.D., Newgard, C.B., Farese Jr, R.V., De Cabo, R., Ulrich, S., Akassoglou, K., and Verdin, E. (2013). Suppression of oxidative stress by β-hydroxybutyrate, an endogenous histone deacetylase inhibitor. Science 339, 211-214.
As for MCT oil (and oil powders), powder formulations tend to cause less digestive distress (e.g. probiotics), but some folks object to the additional ingredients like sunflower lecithin or soluble corn fiber). Even if you’d like to eventually settle on an oil, I’d recommend starting with a powder to see how you respond and to give your body the chance to adapt over time.
Disclaimer: While we work to ensure that product information is correct, on occasion manufacturers may alter their ingredient lists. Actual product packaging and materials may contain more and/or different information than that shown on our Web site. We recommend that you do not solely rely on the information presented and that you always read labels, warnings, and directions before using or consuming a product. For additional information about a product, please contact the manufacturer. Content on this site is for reference purposes and is not intended to substitute for advice given by a physician, pharmacist, or other licensed health-care professional. You should not use this information as self-diagnosis or for treating a health problem or disease. Contact your health-care provider immediately if you suspect that you have a medical problem. Information and statements regarding dietary supplements have not been evaluated by the Food and Drug Administration and are not intended to diagnose, treat, cure, or prevent any disease or health condition. assumes no liability for inaccuracies or misstatements about products.

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 ©