Answer: No—unless you do it for more than a few months. After a few months, the upfront metabolic and weight benefits will begin to reverse and new health problems arise. We know this with confidence. I raise this question once again because more and more people are coming to me reporting problems. It may take months, even years, but the long-term consequences can be quite serious.
Achieving ketosis by engaging in a very low-carbohydrate, high-fat lifestyle is—without a doubt—an effective means of losing weight, breaking insulin and leptin resistance, reversing type 2 diabetes and fatty liver, reducing blood pressure, reversing the inflammation of visceral fat, and may even cause partial or total remission of selected cancers. It means taking advantage of a natural physiological response to accelerate benefits.
So what’s the problem?
The problem comes when people remain ketotic for extended periods. We know with confidence that long-term ketosis poses substantial risk for health complications because thousands of children have followed ketogenic diets over the years as a means of suppressing intractable grand mal seizures unresponsive to drugs, seizures that can lead to irreversible brain damage if not stopped. A ketogenic diet reduces seizures by approximately 55%. Because seizures are a chronic problem, these kids maintain ketosis for months to years.
The health of these kids have been formally tracked. What happens to them beyond the reduction in seizures? A number of phenomena emerge:
- They have high likelihood of calcium oxalate and uric acid kidney stones–Kidney stones are uncommon in childhood, yet these kids commonly have kidney stones. The risk in an adult on a prolonged ketogenic effort is therefore high, also. Kidney stones are not benign–they are painful and can occasionally result in kidney damage (increased creatinine, urinary tract infections, etc.)
- Growth is stunted–Most of these kids fail to grow normally and fall into the 10th percentile for growth or less. Adults on a ketogenic diet are no longer growing, of course, but the growth impairment observed in children suggests that there is something fundamentally wrong with prolonged ketosis sufficient to impair normal growth.
- There are occasional instances of cardiomyopathies (heart muscle diseases, heart failure) and sudden cardiac death–The immediate causes are unclear, though at least some cases are due to severe selenium deficiency. The picture is muddied by the fact that some kids were fed large quantities of corn oil in past as a means of maintaining ketosis. Nonetheless, it suggests further uncertainties with prolonged ketosis.
- Constipation is the rule–as virtual elimination of dietary carbohydrates also means virtual elimination of prebiotic fibers that nourish bowel flora. Over time, this leads to metabolic distortions including a drop in HDL cholesterol, rise in triglycerides, rise in small LDL particles that lead to heart disease, rise in insulin resistance and blood sugar, rise in blood pressure, even if these parameters initially improved on the diet. This is also due to dysbiosis and lack of prebiotic fibers. While this has not yet been tracked in children, in adults we can expect that these distortions in bowel flora will, over time, also lead to heightened inflammation (bowel and elsewhere), diverticular disease (.e.g., diverticulitis), and colorectal cancer. Yes: prolonged ketosis can add substantially to risk for colon cancer. Other peculiar gastrointestinal complications of prolonged ketosis have also been observed, such as protein-losing enteropathies.
- Diminished bacterial species diversity—Not unexpectedly, deprivation of prebiotic fibers leads to a reduction in bacterial species diversity, especially beneficial Bifidobacteria, while E. coli proliferates. Recall that increased species diversity is a consistent marker for health.
While many of the problems that develop with prolonged ketosis may be addressed simply by minding intake of prebiotic fibers, not all are, such as selenium deficiency and stunted growth. (Note that the ideal intake of prebiotic fibers, the level we aim for in Wheat Belly and Undoctored programs, is 20 or more grams per day.) Some have argued that higher beta-hydroxybutyrate ketone levels that develop with a ketogenic diet is all you need to do to maintain healthy bowel flora, but this is a huge extrapolation that does not make sense in light of the newest insights into the microbiome and its metabolites. It ignores the role of hundreds of other microbial metabolites that are required and/or produced that are changed with prolonged deprivation of prebiotic fibers. Also, some have blamed the adverse long-term effects in kids on the seizure medications they take, but the side-effects of, say, drugs such as tegretol, valproic acid, or topiramate do not include the above phenomena.
If you want to use a ketogenic diet as a health tool, it would be wise to do so for no more than a few weeks at a time, as nobody knows how long is too long. And, of course, the period of time during which ketosis is safe can vary from individual to individual. Breaking ketosis is as easy as upping protein intake or having a glass of wine or whole piece of fruit.
Like the stress response, ketosis is a natural, physiological adaptation designed for short-term responses. In other words, an acute stress response to some danger or threat that involves increased adrenaline and cortisol release, increased heart rate and blood pressure, and heightened alertness is normal and can even save your life. But, if the stress response becomes chronic, as it may with divorce, prolonged caretaking of an impaired child or demented adult, PTSD, financial struggles, etc., then the stress response can have terrible health implications that include increased risk for Alzheimer’s dementia, heart disease, dysbiosis, inflammation, diabetes, and cancer. The same applies to ketosis: Acutely, ketosis is a normal physiological adaptation that serves us during periods of carbohydrate or calorie deprivation. Chronically, however, peculiar things happen with consequences that range from constipation, to selenium deficiency and cardiomyopathies, to colon cancer.
Another one of my concerns long-term is that many people are being persuaded to remain on a ketogenic diet over a long period. In 3, 5, or 10 years, we are going to see a sharp rise in colon cancer cases. People in conventional dietary circles will then point fingers at all of us engaged in unconventional dietary advice and we will be lumped together and labeled as dangerous fads. The key is to be smarter and to view ketogenic dieting as the short-term tool/response it is, not as a solution to all health struggles.
Also, be aware that, while diet can be an extremely powerful tool to regain control over many aspects of health, diet by itself remains insufficient for full health. Just as filling up the gas tank of your car with quality gasoline helps your car run well, but other aspects of your car need attention over time (change the oil, tune-ups, new tires on occasion, etc.), so it goes with diet. We must also pay attention to vitamin D and iodine status, the potential for common endocrine disruptions such as thyroid dysfunction, efforts to cultivate bowel flora, and other issues. Focus on diet as a start, not as an end.
So be ketotic—but just don’t stay ketotic for too long. Like an acute stress response, use it to your advantage but don’t allow it to become a chronic impairment of health.
This type of information has also been on the Internet. When I first saw what the consequences could be if this is planned by the person following the Keto diet as being for a lifetime thing, I immediately sent the article to my brother & his wife . They’ve been on this for some time & have lost weight on it. All good, but may not be well for my brother, who has one kidney. It was removed because it was no longer functioning at full capacity.
I am truly worried for him, & wish that he would be on Wheat Belly instead, as it is a much safer food plan to be on. He knows that I am on WB, but hasn’t switched over; I only mentioned this once, & he probably won’t change to WB or another safer venue to be followed.
Thank You for all the articles that you put on this blog. They are so informative and useful.
Is their a difference between burning fat as a primary fuel,(fat adapted), and actual ketosis?
Dietary selenium supplementation through eating 3-4 brazil nuts each day is a widely known and utilized by the keto community. The high fat content of the nuts is not only allowed, but encouraged.
From what I read, the selenium level in Brazil nuts is entirely dependent on the level of selenium in the soil the tree is growing in and can vary from lots to virtually nil. I prefer to take a supplement and know what I’m actually getting.
The criticisms of the ketogenic diet are strikingly similar to those made against Wheat Belly, Atkins and LCHF diets generally. They’re lacking essential nutrients, you’ll get sick – they’re going to kill you!!!! As always, the devil is in the detail and I think Dr Davis is in danger of throwing the baby out with the bathwater.
Regarding the alleged growth stunting and selenium deficiency I’ll repeat a comment I posted before:
https://www.wheatbellyblog.com/2018/10/how-to-become-a-diabetic/#comment-73469
“constant keto supposedly caused selenium deficiency and stunted growth in epileptic kids on keto diets. As I previously commented large areas of North America & Western Europe have Se-deficient soils with the notable exception of the NA grain-growing regions. Consequently the major source of Se in the SAD is grains and deficiency is a result of eliminating the grains on a Keto or WB diet. Opponents could just as easily use Se-deficiency as an argument against WB. The solution is not eating grains it’s taking a supplement.
The claim that keto stunts growth may be wrong. I attended the Low Carb Downunder event in Sydney last month
low-carb-sydney-october-2018/
One of the speakers was pediatrician Jake Kushner and in the Q&A session he was asked about a study that claimed that keto diets caused stunting in children. I didn’t catch the title of the paper but it’s probably the one that Dr Davis is referring to.
Jake said that he was sceptical of this paper as it didn’t accord with his experience of epileptic kids on keto diets. He approached the principal investigator asking to get the raw data and was refused. The study was only for 12 months and didn’t follow the kids to maturity. Jake said it’s well-known that chubby kids develop faster than skinny kids but that doesn’t determine their ultimate height and that the study didn’t address that issue. He said that until they release the data he just regards it as anti-keto propaganda”
My understanding of keto diets is that they eliminate starches and starchy vegetables but that eating non-starchy vegetables is encouraged. Therefore there is no reason why you should be constipated or have bowel flora dysbiosis due to lack of soluble fibre. In fact on this keto diet kids would get more fibre than kids on the normal diet of pizza, pasta and similar junk that passes for the SAD.
Kidney stones are usually a sign of excess oxalates in the diet and/or Vitamin K2 deficiency. If the kids were eating a no-vegetable diet where were the oxalates coming from? If they were eating the vegetables why the constipation and dysbiosis? What were they not eating that caused a K2 deficiency? You don’t have to be on a keto diet to have kidney stones as I know only too well.
In short, if you eat a poor diet lacking various vitamins and minerals you are going to have nutrient deficiencies and health problems regardless of whether it’s SAD, WB or keto. The real question is what exactly was the diet these kids were on? If it was solely hot dogs and corn oil it may have been ketogenic but it certainly wasn’t healthy.
More relevant perhaps is this comment from the late Robert Atkins in his book Dr Atkins’ Age Defying Diet, page 158:
“Hypothyroidism is an extremely common result of being on a weight-loss diet, my kind of anyone else’s, for any real length of time. Your body resists losing weight and thus alters its homeostasis by reducing its production of thyroid hormone.”
This suggests that we should cycle in and out of ketosis by periodically increasing carbs to avoid this hypothyroidism. Incidentally, the more I read of the much-maligned Bob Atkins’ writings the more impressed I become. He clearly was extremely well-read in the scientific literature and modified and expanded his protocols as he got more information. If you read his Age-Defying Diet book, apart from Dr D’s absolute prohibition of grains, it isn’t too different from WB principles. See this quote (page 290)
“The human digestive tract is simply not well designed for digesting grains. The proteins in grain, especially the gluten, are very difficult to digest, even if you don’t have apparent gluten problems. Too much grain, especially of the highly refined kind, is behind many of the cases of food allergies, irritable bowel, chronic indigestion, and yeast overgrowth that I see every day.”
Not bad for a book published in 2000! Substitute the word “any” for “too much” grain and Dr Davis could have written that paragraph.
?? thank you for some great info! USC just had an article about Keto, saying they don’t know the impact on bone health. So I’m not sure why all these articles are written without the documentation to prove the claims. We all know too much calcium supplementation can cause problems but every Dr wants you to supplement calcium. Most people could do a lot worse than doing Keto! The SAD will cause more problems for you than eating whole, unprocessed Keto food! Sugar seems to be the real issue along with aspartame and stressful living.
After reading that article I have to say that the “USC experts” are full of it. It’s the usual scare stuff that the mainstream docs and dietitians trot out to attempt to discredit LCHF and keto diets. There’s no reason why a keto diet should be any worse for bone health than any other diet provided it has adequate calcium, phosphate and Vit K2 and you have good Vit D levels. As for the recommendations of dietitians – eat lots of healthywholegrains and “vegetable” oils but no saturated fats – we know what the long-term results are of that: diabetes, heart disease and osteoporosis.
The whole area of calcium supplementation is rife with misinformation. Mainstream docs assume that osteoporosis is due solely to lack of calcium, ignoring that you need to have adequate Vit D levels to absorb the calcium in the first place (and their idea of adequate D blood levels are absurdly low) as well as Vit K2. Since bone is made of calcium phosphate, you also need adequate phosphate as well. Milk contains calcium phosphate – no surprise since it is designed to build the bones of the growing animal – so dairy is your best source of calcium. You also need protein since bone is calcium phosphate within a protein matrix. To rebuild osteoporotic bone you need 1.2gm/Kg of body weight, 50% more than the RDA of 0.8gm/Kg.
As for the supposed problems with calcium supplementation, this seems to be another case of bad science picked up by the mainstream and repeated ad infinitum. I commented on this in response to another post of Dr Davis’s
https://www.wheatbellyblog.com/2019/02/the-calcium-hoax/#comment-74336
so I won’t repeat it all here. The original study that claimed calcium supplements caused heart disease was widely publicized when it came out but unless you had a subscription to the British Medical Journal you wouldn’t be aware of the serious objections published in subsequent issues. In particular, Lappe & Heaney reported the complete opposite result – calcium supplementation REDUCED heart disease versus placebo.
Kudos t Stuart. Well expressed and thoughtful. I wondered myself what these “strict keto diets” consisted of. I can’t imagine my keto lifestyle without plenty of greens and a variety of meats.
This was very confusing and disappointing to read from Dr. D. Wheatbelly IS ketogenic. In fact, I got kidney stones while following it, along with some other weird symptoms like hair loss and very cold hands and feet. Granted I was probably dehydrated and lacking in some nutrients……but still. I never had those issues while following SAD. On SAD I never worried about drinking enough water or whether I was getting the right scientifically controlled combination of vitamins, minerals, pro/pre biotics. Never had to eat a raw potato or, dear God, a hard, chalky, green banana (who can do that for life? No one). I never got a kidney stone (or the other mentioned symptoms) on SAD. And they all went away when I stopped doing Wheatbelly. Very disappointing because I was losing weight on Wheatbelly and have gained it all back. Anyway, the diets are very similar. If you restrict carbs the way Dr. D says you should…. for life, you will be in ketosis long term.
At this point, I’m searching for the secret sauce that will allow me to follow Wheatbelly or Keto or any other low carb diet, but not develop any health problems. When you have 80 lbs to lose, it’s discouraging to be told that you can’t be on the only diet that has ever worked for more than a few months. I’ll need a year or more just to get to goal weight.
Hair loss and feeling cold could be symptoms of low thyroid hormone.
Jo wrote: «…Wheatbelly IS ketogenic.»
No, it’s not, if you are near the 50 grams net carb per day. This also came up on the Undoctored blog, and here’s a more detailed response there. By the way, the Undoctored blog still has a problem that arose last week. The blog index page isn’t updating, but the articles, comments, and email notifications are working.
re: «I got kidney stones while following it…»
What exact program were you following? What form of magnesium were you taking?
re: «…along with some other weird symptoms like hair loss and very cold hands and feet.»
As Stuart points out, that’s highly suggestive of hypothyroid, which is a top candidate in weight loss stall. Had you been supplementing iodine, and have you had any of the program suggested labs for thyroid optimization?
re: «…whether I was getting the right scientifically controlled…»
What we’re targeting is ancestral levels of nutrient to which humans are adapted (and without the ancestral hazards).
re: «…(who can do that for life? No one)»
I haven’t found it to a problem. The main challenge is that over 98% of what passes for “food” these days is unfit for routine human consumption.
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What is the best way to get out of ketosis periodically? I know you don’t want us to eat pizza or cupcakes. So what do you recommend?
Also, does the l. reuteri yogurt have prebiotics? Of course when you make it, you are adding them (I use inulin), but are they still there in the finished product?
Thanks
Emily wrote: «What is the best way to get out of ketosis periodically?»
Just letting the net carbs float up to 50g/day would suffice. Most fruits, and many veggies do that.
re: «…does the l. reuteri yogurt have prebiotics? Of course when you make it, you are adding them (I use inulin), but are they still there in the finished product?»
The yogurt multiplies probiotics (the bacteria) but not prebiotics (fiber). It won’t have any more prebiotic than you started with/added, and is likely to have less. I add the yogurt to my morning smoothie, but the smoothie has deliberate prebiotic in it as separate ingredients.
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You can absolutely be in ketosis and eat 50g of net carbs a day. Maybe not everyone, but many people can maintain ketosis at that level of carb if fat/protein intake is OK. I have experienced this myself, and tested with blood keto meter. It would be interesting to test people who have been on the WB diet to see how me many are also in ketosis. I would bet a significant portion cycles into ketosis very regularly, and some are ketotic most of the time.
Unfortunately I think Dr. D has too much of a vested interest in distinguishing WB from Keto diet when they actually overlap quite a bit. Especially people practicing keto for overall health, not just weight loss. Having said that, more studies are needed to monitor side effects of keto diets in adults, and it is good to keep in mind that there could be unintended side effects from low carb diets. Fortunately most can be prevented by being aware of them, adjusting to have a well-rounded low carb diet, and taking supplements.
Megan wrote: «You can absolutely be in ketosis and eat 50g of net carbs a day.»
Just as people can vary dramatically in their response to carbs, I would not be surprised if that’s the case for some people. Might this be another case of copy numbers of AMY1 SNPs? But most people need to assume that WB/Undoctored is not a full-time KD. The goal of the 50g/day, 15g/interval is not for elevated ketone levels; it’s for ideal average and peak blood sugars.
re: «I have experienced this myself, and tested with blood keto meter.»
What kind of readings did you see, and when during the day (relative to meals, and meals containing what)?
re: «I would bet a significant portion cycles into ketosis very regularly,…»
If my view of the diet¹ is that it’s borderline glycemic/ketotic, that wouldn’t be a surprise, particularly overnight. Too bad we don’t have CKMs (Continuous Ketone Monitors) yet. The breath meters might be as close to that as we have so far, and are of limited use asleep.
re: «Unfortunately I think Dr. D has too much of a vested interest in distinguishing WB from Keto diet when they actually overlap quite a bit.»
As I point out in that response on the Undoctored blog, we have to start any compare-and-contrast with “which KD?”. With Undoctored and 2014+WB, we know the definition of the entire program. But just as Paleo has no pope², keto has no king, so the varieties of KD are manifold.
The vested interest here is overall health, and not a particular diet brand. Here’s a thumbnail of the history to this point. I characterize the diet part of it as “enlightened ancestral”, and really, evolving EA, because it’s not done yet. Dysbiosis is a major focus at the moment, and the factors and remediations include more than just diet.
re: «Especially people practicing keto for overall health, not just weight loss.»
KD is light years ahead of USDA MyPlateOfMetabolicSyndrome, no doubt about it. But there’s no ancestral case for chronic keto (whereas there is a case for seasonal and sub-seasonal keto). Short-term KD is a tool in the box here. For people not using it as the most benign treatment for a genuine chronic ailment, chronic keto needs caveats.
re: «…more studies are needed to monitor side effects of keto diets in adults…»
Sure, but people need to assess this issue without waiting for the perfectly-designed RCTs that will probably never happen.
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¹ That blog post is partially hidden by some as-yet unresolved server bug.
² Paleo actually does have an originator (Loren Cordain), but since almost nobody doing “paleo” knows that, it doesn’t have a reference specification either.
The children who failed to grow properly were fed 7% protein. A growing child requires more protein than that.
Oxalates are found on veggies and fruits, not meats!! hahaha!!
Here are your high oxalates foods:
Beans.
Beer.
Beets.
Berries.
Chocolate.
Coffee.
Cranberries.
Dark green vegetables, such as spinach.
(splat in my face)
There is a huge spectrum of “macro profiles” that can keep you in ketosis. There are extreme keto diets and moderate keto diets. The article doesn’t seem to address this spectrum.
Do you think there is evidence that long-term ketosis is safer at low levels than high levels (tested by blood)?
And I agree that supplementation is critical. In addition to vitamins and supplements I do use Prebiotin which I learned about on this website.
Elizabeth Cook wrote: «There is a huge spectrum of “macro profiles” that can keep you in ketosis.»
That’s why one of the first issues in comment discussions here is: which KD?
re: «The article doesn’t seem to address this spectrum.»
To a large extent, it doesn’t need to, because what all KDs have in common is net carbs lower than the WB/Undoctored program, which makes getting sufficient prebiotic fiber carbs a challenge (even for those aware of the issue, which most people doing KD are not).
re: «Do you think there is evidence that long-term ketosis is safer at low levels than high levels (tested by blood)?»
In the narrow cases where chronic keto is actually a net benefit, and gut flora is being addressed, that’s an interesting question, and one I don’t recall seeing addressed anywhere. It would raise the further question of whether exogenous ketones need separate consideration.
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I would like a link to this study please
I can’t believe Dr Davis can compare keto diet for seizures against the keto diet for weight loss! The kids on the seizure diet are eating way more fat than the people on the regular keto diet. Those kids eat large amounts of mayo on a lettuce leaf as a meal!
If you’re doing the keto diet correctly you should be eating lots of green leafy vegetables and cruciferous vegetables along with eggs, meat, fish and dairy if it doesn’t bother you. You would get all of your macro and micro nutrients from eating meat cheese nuts and veggies. It is a well-balanced diet.
There are people who’ve been on the KetoDiet since the 70s and 80s who are in optimal health.
I think Dr Davis has Grain Brain to write such a simplistic no scientific article!
You taught me so much and now you say keto is dangerous? What in the hell? I am totally let down by you . Keto has saved my life . You should follow Dr. Berry and have some of these myths busted. You lost a fan in me today and I will push your own words in your book as truth . not this crap you just posted . * shaking my head*
Marsha Somelass wrote: «…and now you say keto is dangerous?»
a. You may be misunderstanding the message, and
b. the message is not new:
2012-11-27 endorsement: I lost the wheat, but didn’t lose weight: 2
2017-06-14 caution: The Keto Trap
2018-02-02 caution: Be ketotic . . . but only sometime
2018-03-14 endorsement: Maybe it’s time to check your ketone level
Sub-seasonal keto is, and remains, a fully-endorsed tool in the Wheat Belly and Undoctored boxes for addressing various metabolic challenges.
Chronic keto carries caveats. It is indeed often the most benign approach to certain actual chronic ailments (but even there, people need to study the long-term outcomes, note the side effects, and take any available steps to mitigate them).
Casual chronic keto is at some risk of those same side effects. Sure, there are sporadic anecdotal cases where there appears (so far) to be no harm, but these are not large population RCTs. The KD-in-epilepsy data is closer to being RCT data. There being no ancestral case for chronic keto, we need to learn what we can from the formal studies (and sure, endeavor to separate the ailment, med and diet effects).
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