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But over a matter of weeks, the muscles stop using these ketones for fuel. I'm about a week into keto-adaptation, consuming 10g carb, 85g protein, and g fat daily and supplementing with salt, magnesium, and potassium, among other micronutrients. These symptoms can be minimized by making sure to eat lots of fat, staying hydrated, and using salt liberally. Instead, muscle cells take up acetoacetate, reduce it to beta-hydroxybutyrate, and return it back into the circulation. Excess sodium can deplete potassium.


Hi there, I went through exactly what the article described the diffrent phases of adaptation. The result is wow! I can fast for a full day and be very active without suffering from hunger or weakness. I don't think about eating all the time and I get a lot of time for some cool activities. The major source of energy is fat oils, butter, eggs, ghee - I just made my own today, meat fat, etc while I eat meats and nuts for proteins.

In the post, you write "When ketone levels are low, the muscles tend to use them directly for fuel, but as levels increase, the muscles use them less, turning to fat for fuel instead. Or is there a fat oxidation pathway that doesn't involve the production of ketones? Hi Neeraj, sorry for the long delay. I think what Volek and Phinney are saying is that when the amount of circulating ketones gets to a high enough level, the ketone bodies themselves will be used for fuel even by the muscles.

Below that point they will be reserved for the brain. I think you reversed it, probably accidentally. Beta-hydroxybutyrate and acetoacetate are made in the liver in about equal proportions, and both are initially promptly oxidized by muscle. But over a matter of weeks, the muscles stop using these ketones for fuel. Instead, muscle cells take up acetoacetate, reduce it to beta-hydroxybutyrate, and return it back into the circulation.

Thus after a few weeks, the predominant form in the circulation is beta-hydroxybutyrate, which also happens to be the ketone preferred by brain cells as an aside, the strips that test for ketones in the urine detect the presence of acetoacetate, not beta-hydroxybutyrate. The result of this process of keto-adaptation is an elegantly choreographed shuttle of fuel from fat cells to liver to muscle to brain.

But, of course, the level of ketones, would also go up over time. Oliver, I do sometimes make mistakes, but I'm not sure what you think is mistaken here. I don't see anything inconsistent. Could you be more specific about what I may have "reversed"? I was replying to the comment right above mine where you said: I don't mean to criticise. Just want to avoid confusion. Friendly criticism is good! I'm not sure about why I wrote what I wrote just above.

Thank you for pointing it out! Oliver, I think I may have just phrased things badly above. When keto-adapted, muscles are using more fat, but they are still also using ketones. It's just that when blood ketones are higher, muscles use relatively less of what's available.

Presumably this is because high levels of ketones indicate low levels of glucose, which means the brain now needs to get priority for the ketones. But if there is so much in the blood that the brain's needs are met, there will be more available to the muscles as well. Thank you for pointing out the potential confusion. Nothing but meat for four years!?!? I think massive acidosis is coming your way. Aren't you worried about that? I'm not sure what you mean.

Are you confusing ketosis with ketoacidosis? Or are you talking about the common misconception that certain foods have a significant effect on blood pH? I'm not worried about either of those things. I'd like to address them in the myths section, but I'm quite busy with my thesis right now.

There is a good description of ketosis vs. Hi Amber - Thanks for this blog, it's a great resource. I'm about a week into keto-adaptation, consuming 10g carb, 85g protein, and g fat daily and supplementing with salt, magnesium, and potassium, among other micronutrients. I find that my mental alertness and physical energy level are generally solid until my first substantial meal, after which I fatigue significantly and become rather listless.

Have you ever experienced this or heard about it? Could this be something that levels out as I become more keto-adapted? You said you experience this dip in mental alertness and physical energy after a "substantial meal. Remember, digestion is an energy-intensive process. This is why I think people tend to be semi-comatose after Thanksgiving dinner. It certainly has nil to do with the tryptophan in the turkey. It could be the huge bolus of carbs, but more likely it's just the sheer volume of food, regardless of macronutrients.

You might try just making the meal a little smaller and see what happens. I haven't heard of that kind of experience. Have you looked at your blood sugar before and after the slump? No I haven't, thanks for the suggestion.

I'll check it out! I have tried to adapt to low carb but starting from the point I reduced carbs under grams a day I have had a huge energy crash. I brought it down to under 50 grams at one point and that made the symptoms even worse. I suspect that what I am experiencing is some kind of electrolyte imbalance.

The main symptoms I am suffering from are a complete collapse of energy levels I went from working 14 hours a day to four hours a day, with bouts of unbearable fatigue throughout , absolutely no energy in my muscles and as a result I can no longer do high intensity exercises like sprinting. Under 50 grams of carbs a day, I started to see the really serious electrolyte issues like change in breathing patterns, cardiac rhythm problems, and muscle cramping.

I am prediabetic with A1C around 5. But I had some kind of osmotic reaction to that and it causes loose bowels. A big concern I have with supplementing high doses of electrolytes is that the four major electrolytes need to be in proper balance. Excess sodium can deplete potassium. Excess potassium can interfere with magnesium. There are ions and corresponding anions to balance. When we get these things from food presumably they are in balance.

When we start taking five grams of sodium from celtic sea salt, that makes me think the others need to be brought in the proper balance, and I have no idea what the right balance is. Even Volek and Phinney's book only gives this topic the most shallow treatment. Is there any place to read deeper on this? The other thing I badly need to identify is a doctor who works with low carb diets and is familiar with these electrolyte issues.

I cannot locate one. I have problems even finding nutritionists who specialize in ketogenic or low carb. The doctors who advertise on places like "Low Carb Docs" are either general practitioners with no specialization in diet or low-carb, or mostly chiropractors who again appear to have no specialization in diet. I clicked on every single profile on the Low Carb Docs list, and not ONE of those had a web site that proclaimed any kind of diet specialization.

In terms of ketones, I measure with a blood serum meter. I don't get many ketones when rising, but usually after a mid-day salad I start piling on extra fat and ketones will get up to 0. No amount of fat eating seems to move me much over that 0.

After 30 minutes of walking, and then only eating fats during and after that exercise, an hour after exercise I can reliably get ketones to 1. I definitely feel better, but the high ketones really just feel like a mask that covers us the energy loss.

If I had to make a wild guess, I think what is going on is that my body is shedding both sodium and potassium, and my body has significantly shrunk its fluid volumes. It's the collapse of fluid volumes that leaves me with the unbearable fatigue. On blood tests during the subgram phases of low carb, my sodium tested at When I am closer to 80 to grams of carbs my sodium tests low normal range. I'm not a doctor, and all appropriate disclaimers apply. Electrolytes can be very helpful for adaptation, and you should be able to count on your body to correct the ratios, provided you give it enough of each.

That is, I wouldn't worry about trying to match your intake ratios to what your body is going to optimally adjust to. However, I don't think that's your problem! I think you aren't keto-adapted, especially if going all out only gets you to only 0. Staying between 50 and g of carbohydrate is, in my opinion, the worst possible choice. It's too high to adapt and too low to feel good on a sugar-based metabolism. Amber, I did limit to under 30 grams a day for a month, and that left me literally out of breath, pounding heartbeats, massive fatigue, absolutely disabled.

I tried to supplement sodium up to five grams additional in drinking water, which I did not tolerate well because it created some kind of osmotic diarrhea in my gut. I don't believe that most of the fatigue I experienced was due to ketones. I was losing up to four pounds of body weight just in sleep, never going to the bathroom.

That has nothing to do with ketone levels. That has to be a diuretic effect from the diet, and nothing I did could control it. The thing is even increasing my carb levels I have had problems getting back to any kind of baseline. I have been with these symptoms for five months. I have eaten less than 30 grams for more than a month. Every time I increase carb levels from 30 grams I start to feel a little bit better, but still have not recovered.

This diet has completely messed me up. Low carb or ketogenic is a miracle diet for people who are overweight. They have extra body fluid, so a diuretic is a very beneficial thing for them. But people who start out skinny and don't have any extra fluid to lose have to manage that issue very carefully. It was beyond my skill level, and my experience, to navigate this.

For some of us, these diets are very technically challenging diets to implement, and there are simply no good professional resources available to us to help us through it.

Amber, is there any article on the site that shows what the ketone levels are over a 24 hour period, for a keto-adapted person? It would be interesting to see how those numbers ebb and flow over the 24 hour cycle. Well, I'm really sorry you are having such a hard time. It's hard to troubleshoot from afar. I would have to know a lot more about you to even hazard a guess. I'm pretty confident that your problems are not because you don't have a weight problem.

Lots of people who are already in great shape use ketosis to enhance endurance. I also have at least one friend who keto-adapted quite easily and has never been overweight. I have another friend who had a very hard time on ketosis that turned out to be almost certainly due to adding large amounts of coconut oil to her diet, which she turned out to have an intolerance to, because of the salicylates.

So you might look to see if you have greatly increased a food that wasn't part of your regular diet before, that might be triggering an intolerance. At one point, I think Jimmy Moore was keeping a list of low-carb friendly doctors. You might try looking on his site. I don't have data on the circadian cycle of ketones, but I know they tend to be lowest in the morning and highest in the evening.

Best of luck, Amber. The salicylate reaction was an IgE type allergic reaction? My symptoms are extreme, but there are many many people blogging online how they crash on low carb diets. So that is extremely common. Advocates of these diets always say it is a keto adaptation problem. Yet my ability to lose four to five pounds a night and constantly be dehydrated, even when my ketones were high, tells me that it is just more complex.

At least for some of us I went through Jimmy Moore's list a while back, and none of those people have web sites that convince me they specialize in low carb or ketogenic diets. You might think about a post in the future documenting ketone levels throughout the day. It would be incredibly useful to anyone who attempts one of these diets to have a target baseline, so they could compare their own results to someone who has been successful with the diet.

I understand your frustration. It is very difficult to have a health problem and no answers. I've certainly been in that situation, and it's terrible. I think the reason people like me who have been in this community a long time will point to keto-adaptation first, is because it is a very common problem. I have had many experiences with people having problems who turned out not to be keto-adapted. Also, your first letter was unclear to me. It sounded like your carb intake was much higher.

Beyond that, it does get complicated, and I'd have to learn a lot of detail about your life, and devote a lot of time. I'm sorry I can't help you further. Too bad about Jimmy Moore's list. Another list I recently heard about is this one: Hi P1, have you tried making and drinking bone broth on a daily basis.

I am a thin person doing the Ketogenic diet for Chronic Fatigue Syndrome, not weight issues. When I decided to switch to a Ketogenic diet, I did so by drinking 2 quarts of bone broth every day with sea salt to taste.

Bone broth provides both potassium and magnesium. Stefanssen, the arctic explorer who lived off the Inuit diet himself, said that the Natives emphasized to him the necessity of drinking bone broth on this type of diet. I have had a very easy transition to a Ketogenic diet and I suspect this may be why.

I have, however, discovered that I have other food sensitive issues - like salicylates - and I have had to eliminate ALL plant-based foods from my diet, along with eggs, in order to feel my best.

I hope this helps. My potassium always tests at 4 to 4. I read somewhere that low carb diets can increase cortisol, and cortisol in turn can cause intracellular potassium to deplete. I don't know my cortisol situation yet , as it took me fully five months just to figure out that my problem was electrolyte related, and to get my doctors thinking about that issue at all. Everything in fixing this moves very slowly.

For me, the low carb diet has been life-crushing. Every aspect of my life has been adversely affected by this situation. I badly need the help of a doctor or nutritionist with expertise in both low carb and electrolytes, but I literally cannot find anyone. The people who know about these things - like Dr Eades - do not take patients. They write books, blogs, and give speeches. I get the feeling that low carb diets are fantastic for people who start from a point of being overweight, insulin resistant, and fluid bound.

Those people greatly benefit from the diuretic effects of the diet. Those - like me - who start out skinny and not particularly insulin resistant end up getting squashed like bugs. I see a lot of people online complaining about the cardiac rhythm issues, muscle cramping and loss of muscle energy, and overwhelming fatigue that I too suffer from. Being such a stubborn person, I just refuse to believe there is not a way to get myself out of these electrolyte hell-hole. I am very appreciative of any ideas you might share, and particularly for any human resources who actually focus in this area and might be willing to take on new clients.

I am badly in need of some help. Hi P1, This is my first time posting on this site and I am a newbie to keto adaptation with a 30 day close to zero carb initiation. In my case I have pushed my ketosis up gradually over a multiple year process. I have been on a lifelong health research project which subjected me to most of the popular extremes such as vegetarianism and veganism. Fortunately I didn't stay on any food intake program when my symptoms interfered with my physical wellbeing for an extended period of time.

Although I would continue the education process, I would resume eating in the last known way that had me on a path of overall wellness and ideally some improvement. In that way, I could evaluate the particulars which caused me an inability to continue with a food program from a general condition of physical functionality. I did notice that your description of your fat intake included the use of olive oil as a fat source alternating with baking chocolate and MCT oil.

Amber mentioned a concern about possible allergy to the salicylates in Coconut fat from which MCT is derived and I did not notice any comment about that from you. Also, Olive Oil is NOT a good fat choice for a beginning Keto-adapter because it is a long chain triglyceride which does not turn into a ketone but must be digested for assimilation. Butter, Coconut Oil, and animal fat ie. Take minerals with your fat intake as many of them require fat to be absorbed. Take it easy on yourself.

I believe there is an answer for your challenges if you have the patience to keep adding to what works for you and leaving behind what doesn't. Olive oil is also very high in salicylates, as are avocados. I strongly suggest a trial of eating only animal-based foods for a period of time in order to eliminate this confounding factor. Hi Amber, If anyone has a tough time accepting that our brains can run on ketones with a minimum of glucose, they need only take a look at this study from Base line insulin tolerance tests were administered in the postabsorptive state with the subject at bed rest.

Repeat tests were carried out in nine subjects after a minimum of 60 days of fasting which had resulted in a mean weight loss of 73 lb. This is the kind of thing that could be done back then, especially at a VA hospital. Yet they had no symptoms of hypoglycemia. So, as long ago as the early 70's, some doctors had an inkling of the brain's ability to run almost purely on ketones. These guys were fasting, so they had no protein intake to provide the raw material for gluconeogenesis.

I suspect they were wasting their muscles to get the bare minimum of glucose needed. I would like to say the same thing, it's really a unique blog article. I read about Keto-adaption first time. Hi, love your work! I need some help. I have been on keto diet for 17 days now. I have had absolutely NO carbs in that time. Am also having my two teaspoons of salt per day and drinking plenty of water. I am experiencing all the benefits of a keto diet - weight loss, even energy levels, long periods of satiety, etc.

The only issue is I have had is watery bowel movements for the last two weeks. It is not like I have chronic diarrhea, as I still just go twice a day as I always have, but I have not had a solid stool for the last two weeks - it's starting to concern me. Any advice on how I can address this issue?

That is not unusual at all, and typically normalises over time, though it will probably not ever get as firm as what you are used to. By the way, if you are really eating no carbs at all, by which I mean no plant sources, I personally consider this ideal. It is how I eat, and I interact with many others who do the same. We have found through collective anecdote that the benefits are retained at a higher protein ratio than with a keto diet that includes plants.

There is a small group of zero carbers in the discussion forum linked at the top. I have read that this sort of issue is common through the adaption period so I expected it, but most seem to say it corrects within a few days to a week, which is why I was concerned. I'll hang in for another week and hope it returns to some sort of normality.

I'll def check out the zero carbers. Keto-adaptation is the process of shifting your metabolism from relying mostly on glucose for fuel, to relying mostly on fat-based sources of fuel.

Not only does fat oxidation itself increase, but your body starts producing enough ketones that they can be used as a significant source of fuel as well. Ketones are derived from partially metabolized fat, and they can be used in many of the same tissues of the body as glucose can, including much of the brain.

The benefits of using fat and ketones rather than glucose for fuel are many, and are the main subject of this site. However, it takes time for the metabolism to adjust to producing and using ketones at a significant rate. Even though changes are evident within days of carbohydrate restriction, improvements continue for weeks. Carbohydrate-based fueling is a self-perpetuating cycle: Fat-based fueling is sustainable, because it allows access to a very large store of energy without you frequently stopping to refuel.

Blood sugar is maintained though precise internal processes without wild swings. These two together create a desirable flow of even, stable energy, mood, and alertness. There is a delay between first reducing the amount of carbohydrates that you eat, and having a smoothly running fat metabolism. In the intervening days, you may feel slow, or even unwell. These symptoms can be minimized by making sure to eat lots of fat, staying hydrated, and using salt liberally.

Other electrolytes may also be helpful to add -- homemade broth makes a good supplement. Keep carbs consistently low, or you will never adapt and the process will go on indefinitely. Carbohydrate-based fueling is a self-perpetuating cycle. The body can store only relatively small amounts of glucose, in the form of glycogen. About grams can be stored in the liver, and about grams can be stored in the muscles.

Muscle glycogen can only be used by the muscle it is stored in — it can't go back to the bloodstream — so the liver glycogen is the only source that can be used to keep blood sugar stable, and provide fuel for the brain. If you are not making use of ketones for fuel, then this is not enough glucose to get through a typical day, let alone a day when you are doing something strenuous.

If you depend on glucose metabolism, then you have to frequently replenish your glycogen stores or you will begin to feel tired, physically and mentally. There are basically two ways to get the necessary glucose, and only one of them involves eating it.

The first is to eat carbohydrate. Unfortunately, every time you ingest more than a small amount of carbohydrate, it stops all progression toward keto-adaptation. So this strategy is a Catch It makes you continually dependent on dietary carbohydrate.

It locks you in, because supply is limited, but restocking prevents other fuels from becoming available. The other way to get glucose is to let the body make its own on demand out of protein. This process is called gluconeogenesis. Gluconeogenesis is the reason that eating carbohydrate is not necessary, even though some amount of glucose is manufactured and used internally. This is analogous to any other internally produced nutrient, such as vitamin D, which we don't need to ingest, because the body makes it in response to sun exposure, or to a hormone, like adrenaline, that we make and use every day, but don't need to get from food.

One of the benefits that comes directly from this physiological mechanism is that on a keto diet you will no longer need to eat so often.

Skipping a meal does not become an emergency, or even a problem. A lot of people have problems with mood, cognition, and wakefulness if they don't eat frequently. On a keto diet your blood sugar will naturally become steady, and the advice to eat every 3 hours to prevent hypoglycemia will become irrelevant.

What exactly happens during keto-adaptation? In the first few days of a keto diet, your body is still running on glycogen stores. This is the toughest part of the process, because in order to break the vicious cycle of glucose-based metabolism, you have to avoid eating carbohydrates, even though your glycogen stores are dwindling. Fat metabolism is still not optimized, and ketone production hasn't become significant.

Another noticeable effect in the first days is water loss. One of the inefficiencies of glycogen storage is that it needs to be stored with water. It takes about 3 or 4 grams of water to store a gram of glycogen [1]. This means that as you deplete your glycogen stores you could lose up to 2 kg of water! Not only that, but high circulating insulin levels cause water retention by inhibiting sodium excretion see e.

The keto diet lowers insulin levels and increases insulin sensitivity, allowing excess fluid to be released. These combined effects are the origin of the claim that the weight lost on keto diets is due to water loss. In the very beginning, this is true, but subsequently, of course, it is not.

When glycogen runs out, you start producing ketones, and some are excreted in the urine. This is easy to measure, and some keto dieters use it to know if they are hitting a low enough level of carbohydrate restriction. This also marks the beginning of the second stage of keto-adaptation. Ketones are now becoming available for fuel, but they haven't yet risen to their stable adapted level. There is an interesting interplay between ketone use in the muscles and the brain. When ketone levels are low, the muscles tend to use them directly for fuel, but as levels increase, the muscles use them less, turning to fat for fuel instead.

The brain, on the other hand, uses ketones proportionally to their concentration in the blood. This means that at low levels of ketones, the brain's supply is not much affected, because the muscles intercede, but above some threshold, the brain's supply rapidly becomes much higher.

At this point, the brain can rely on ketones, and since it is no longer susceptible to running out of fuel, the need to eat frequently throughout the day to maintain mental function disappears. The muscles in turn now rely on fat: Much confusion has been generated by scientists not recognizing one or both stages of keto-adaptation. A few studies have been publicized claiming that low carbohydrate diets worsen mental or physical performance e.

On reading the details, it turns out that the testing was done in the first few days of carbohydrate restriction. Obviously, these studies are not valid criticisms of the keto diet, except as measurements of the initial adaptation cost. They do not reflect the longer-term outcome. How to make keto-adaptation as quick and painless as possible As noted above, the difficult part of keto-adaptation is the first stage.

There are two reasons. The first is that glucose is less available, but fat and ketone metabolism haven't effectively taken over. The best strategy for coping with this is to eat a lot of fat. Even if you eventually wish to get most of your fat from your fat stores, you do not normally need to restrict it in the diet, and especially not now.

Fat is an important source of essential fatty acids and nutrients. Moreover, ingesting fat with protein helps to moderate the insulin response. A keto diet is not a high protein diet, it is a high fat diet.

Do not fear it. Eat plenty of fat during keto-adaptation to ensure you have energy available. The second difficulty is a result of the sodium excretion and transient rapid water loss we mentioned.

If care is not taken to replenish sodium and water, both sodium and potassium are sometimes lost too rapidly. This can cause tiredness, weakness, and headaches. Be sure to get enough sodium: Oxytocin is a strong stimulant of uterine contractions. What role do the kidneys play in erythropoiesis?

The kidneys detect low levels of oxygen in the blood. What triggers erythropoietin EPO production to make new red blood cells?

What organ in the body regulates erythrocyte production? Ghrelin, produced by the stomach, is a powerful appetite stimulant. Many factors influence BMR. What is the most critical factor? The preferred energy fuel for the brain is fat. Which hormone directs essentially all the events of the absorptive state? Which of the choices below happens during the absorptive state? Anabolic processes exceed catabolic ones. Where are oxytocin and antidiuretic hormone ADH made? Which of the following is not a category of endocrine gland stimulus?

Which of the following is not a steroid-based hormone? It does not require a second messenger to effect a response. Oxytocin and ADH are produced in the posterior pituitary. FSH stimulates sperm production in the testes. Iodine is an essential element required for the synthesis of thyroxine. Thyroid hormone production requires the presence of iodine and calcium. The prime metabolic effect of cortisol is gluconeogenesis.

Addison's disease is due to a insufficient output of glucocorticoids only. Hypersecretion of catecholamines can result in hypertension. How do glucocorticoids enable the body to deal appropriately with stress? The pineal gland is used as a brain orientation landmark for brain X rays. The hormone that raises blood sugar levels is insulin. Which organ is responsible for synthesizing ANP?

The beta cells in the pancreatic islets produce insulin. Which of the following is not a cardinal sign of diabetes mellitus? Which of the following hormones suppresses appetite and increases energy expenditure? Most type 2 diabetics do not produce insulin. What part of the body does erythropoietin EPO target to increase erythropoiesis?

Identify the thyroid gland. What is the primary function of hormones? What amino acid-based hormone uses the direct gene activation method illustrated in this image? What is required for the production of anterior pituitary gland hormones? What gland secretes growth hormone? Where is thyroid-releasing hormone TRH made? Which hormone is the body's major metabolic hormone? What type of cell is shown at letter C? What hormone is released by the cells pictured in letter D?

Which of the following would result from hypoparathyroidism? Which of the following is NOT a property of endocrine glands? Which of the following is NOT an endocrine gland? Which letter represents the adrenal glands?

At what point does the receptor-hormone complex bind to DNA? Which of the following is a hormone produced by the posterior pituitary? Which of the following hormones mainly serves to stimulate milk production by the breasts? Which of the following hormones helps the body avoid dehydration and water overload? Major hormones circulate to virtually all tissues. Where are the hormones oxytocin and antidiuretic hormone ADH stored?

What is the target organ of thyroid-stimulating hormone TSH? What is the target organ of thyroid-releasing hormone TRH? Name two hormones produced by the gland identified by letter B. Which of the following hormones regulates blood calcium ion levels? What type of stimulation controls parathyroid release? What cells release parathyroid hormone? Which of the following glands is found atop the kidneys? What factor inhibits aldosterone release? Which pancreatic hormone functions to lower blood glucose levels?

Which of the following best describes the main effects of insulin? Which of the following is a hypoglycemic hormone? Which hormone is involved in diabetes mellitus DM? Which of the following triggers the release of glucagon?

Which hormone can indirectly control insulin release? Which of the following best describes gluconeogenesis? Hormones are long-distance chemical signals that travel in blood or lymph throughout the body. Cyclic AMP and calcium may be second messengers. Nitric oxide is known to be the first gas to act as a biological messenger.

Which of the following does not serve as a signal for cell division?