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Introduction
Is it safe to be in ketosis or eat a ketogenic diet long term? This is a question that comes up often with conflicting answers. An online search will result in concerns about nutrient deficiencies, eating disorders, and other poorly supported claims. So, what's the real answer? Well, the real answer is yes. People can be in ketosis and eat a keto diet long term. Now that doesn't mean everyone should, but if someone puts their treatment resistant mental illness or their type two diabetes into remission with ketogenic therapy, then there's no clear evidence that continuing ketogenic therapy long-term is harmful. Let's get into the details.
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If you've improved your mental health or maybe even put your mental health disorder into remission with ketogenic therapy, do you have to worry about staying on it? Well, at Metabolic Mind, we frequently get comments and questions surrounding the safety of long-term ketosis. So I'm going to address this in detail, digging into many of the supposed reasons why someone shouldn't be in ketosis long term, including things like nutrient deficiencies, disordered eating, cardiac risk, or the claim that ketosis only works for six months and more.
But before we get started, please remember our channel is for informational purposes only. We're not providing individual or group medical or healthcare advice or establishing a provider patient relationship. Many of the interventions we discuss can have potentially dangerous effects if done without proper clinical supervision. So consult your healthcare provider before changing your lifestyle or medications. And in addition, please recognize that people may respond differently to ketosis and there isn't one recognized universal response.
Weighing the benefits & adverse effects of medical treatments
Now, let's start with some perspective maybe, right? Where's the burden of proof? If someone takes an antipsychotic medication or a type two diabetes medication like insulin and it causes weight gain, worsening metabolic health or sexual dysfunction, but it helps reduce the psychotic episodes or lower blood sugar, then the general assumption from the medical establishment is that the benefits outweigh the side effects and it's safe to do long term. They aren't asking if it's truly safe given the concerning side effects, but because the benefits seem to be okay, they continue the medications long term despite the adverse effects.
Well, now let's replace those antipsychotic medications or the insulin injections with ketogenic therapy. All of a sudden, someone may put their mental illness or their type two diabetes into remission without all the concerning medication side effects. So why now, all of a sudden, would doctors and individuals wonder if this is safe long-term? I think it's crucial to start from this framework of understanding the benefits before questioning the risks. If ketogenic therapy were just one of dozens of choices that worked equally as well as the others and with similar side effects, then we'd probably need a lower level of evidence of harm to be concerned. But that's not what we're talking about here.
As published studies from Dr. Albert Danan and Dr. Shebani Sethi and others have shown, people with serious mental illness for years or decades treated with aggressive standard medical care can improve their symptoms quickly and dramatically with ketogenic therapy. So let's look at it through that lens. Now, all of a sudden, the burden isn't for someone to prove that this way of eating is healthy with long-term studies. The burden is probably the other way: to prove it's not. After all, it's just food. It's food that works as well or better than medications for many people with tremendous benefits. So where's the burden of proof for individuals who have dramatically changed their life? Now we have some perspective, but let's get into the details here.
Why do people think long-term keto is dangerous?
Why do some people think long-term ketosis is dangerous? Well, one reason is simply misinterpretation of the science. Some long-term observational studies report that those eating low-carb diets have a higher risk of premature cardiac or all-cause death. But unfortunately, they define low carb as 25% or even 37% of their calories from carbohydrates, which is nowhere near ketogenic therapy, which is usually 30 grams of carbs or less. It simply isn't accurate to assume that these data apply to ketogenic therapy.
Have people been on a keto diet long-term?
Another common concern is that there are no known populations that have lived in ketosis long-term. Well, this isn't exactly true. Hunter-gatherer populations have likely been in and out of ketosis long term, and the Inuit tribes consistently ate a very low carb, high fat diet, although there's some speculation their genetics may influence whether or not they were in ketosis. But the point being, populations have been in and out of ketosis long term.
But what about other diets like vegan diets? Well, there's a quote from the World Health Organization that the evidence on the long-term health impacts of vegetarian and vegan diets remains incomplete. So the same can be said about long-term knowledge of vegan diets, right? And certainly the same can be said about the standard American diet. We know no healthy population has ever followed that diet long-term. So there seems to be a disconnect in the questioning, and it's not significant evidence against the safety of long-term ketosis. And again, we have to ask, where's the burden of proof? I'm going to keep asking that question.
Nutrient deficiencies in a keto diet
Okay, where's the burden of proof? But here's another important topic that comes up frequently: nutrient deficiencies. To dig into this, I did a search of popular online resources and public published articles to come up with the top potential nutrient deficiencies on a ketogenic diet.
The first is fiber, which is interesting because there's actually no body requirement for fiber from our diets. There are official recommendations for how much fiber we should eat, but importantly, the data for this is derived from studies comparing versions of high-carb diets. So the data suggests that if someone's eating a high-carb diet, eating more fiber is likely beneficial, which makes sense, especially when you think about ultra-processed foods that are high carb and low fiber. We shouldn't be eating those. But the same data don't exist for true low carb diets, so it's very speculative to say that low fiber intake is harmful for those in ketosis. And remember, ketogenic diets include above-ground vegetables, avocados, and nuts, which are good sources of fiber. So a ketogenic diet doesn't even have to be a really low fiber diet. That one doesn't really make sense.
Another is phytonutrients, which are found in vegetables and fruits. Again, there's no body requirement for phytonutrients. Studies point to their antioxidant properties and therefore assume they must be beneficial. But wouldn't the amount of antioxidants you need be predicated by the amount of oxidation in your body? And aren't there other ways to get antioxidants? The answers are yes and yes. So once again, this potential deficiency is not really an issue.
Then there's a list of specific nutrients, which I find amazing that anyone would publish, because basically they're all incorrect. Let's go through them quickly, one by one. The first is thiamin, which is found predominantly in fortified whole grains, but it's also in meat, pork, and fish, all very common on a ketogenic diet. How about folate? Also found in whole grains, but also in leafy green vegetables, peanuts, seeds, and liver, all found on a ketogenic diet. Vitamin A is commonly thought of as being in carrots, but it's also in organ meats, fish, and leafy green vegetables, all on a ketogenic diet. Vitamin E is commonly associated with seed oils, but it's also in almonds, peanuts, greens, and bell peppers, again all common on a ketogenic diet. Vitamin B6, which most Americans get from fortified cereals, is also in liver, tuna, salmon, and dark leafy green vegetables. Then I saw calcium listed, which I couldn't believe, as it's common in dairy, sardines, and almonds. Okay, enough said about that. And potassium, which is thought to mostly be in vegetables, is also in meat and avocado.
So all of these commonly cited nutrient deficiencies are simply wrong. There's no convincing evidence that a well-formulated ketogenic diet is deficient in any of these nutrients.
Is there an increased risk of heart disease on a keto diet?
All right, now let's transition briefly to a big one: is there an increased risk of heart disease in ketosis? We have a whole video dedicated to this one, so you can watch that video for more detail. But in short, ketogenic diets can be vegan, vegetarian, Mediterranean, omnivore, carnivore, or others. So they certainly don't have to contain saturated fat and meat. But even when they do, the majority of the studies demonstrate no significant increase in LDL, and some even show a reduced calculated cardiac risk because of dramatically improved metabolic health. It is a small minority who see a significant rise in their LDL, and we're grateful for our ongoing research investigating this unique population and their unique physiology. But in short, there is no evidence that being in ketosis long term is automatically going to raise your LDL and increase your cardiac risk. In fact, there's more evidence to the contrary. And again, if we're citing studies that use 25% or 40% of calories from carbohydrates to suggest increased cardiac risk, that's simply false. That's not ketosis, that data does not apply to ketosis, and we should not be combining it.
Does a ketogenic diet increase the risk for disordered eating?
We've covered a lot, but there are two more I want to touch on. The first is a quick one: that long-term ketosis will lead to disordered eating. There is simply no evidence to support this. Any data that comes close is low quality and suggests that really any diet can slightly increase the risk for disordered eating. But there's no specific data for ketogenic diets. It simply doesn't exist.
Does ketogenic therapy work for longer than 6 months?
The last one is the claim that ketosis only works for six months. This claim comes from studies looking at weight loss, mostly not ketogenic therapy for brain-based disorders, and it's certainly not true for type two diabetes, where Virta Health has published two-year data and presented five-year data at a conference, both of which demonstrate impressive sustained benefits. I won't spend too much time on this, but one reason is poor trial design. Let's take the DIETFITS trial. It's an often cited study showing that low-carb diets don't work long term and are no better than low-fat diets. But let me read from the trial design. It says: "The second component of the dietary strategy involved instructing participants to slowly add carbohydrates back to their diet in increments of five to 15 grams per day for periods of a week at a time with no set endpoint goal for a specific level of fat or carbohydrate." Let me say that last part again: no set endpoint goal for a specific level of fat or carbohydrate. What that resulted in was that at three months, the low carb group was eating 96 grams of carbs per day, so right away it's not ketogenic. The low fat group was eating 205 grams of carbs. But at 12 months, the low carb group was eating 132 grams of carbs per day. Remember, this study is often cited to demonstrate how low-carb and keto diets don't work long term. Well, if you're not eating low carb, it's not going to work, and they clearly were not eating low carb at the end of the study. So trial design makes a big difference.
The other part is that we know, in studies, adherence to any diet drops off, keto included. But the question we've been asking throughout this video is not about that. The question is, for those who remain in ketosis, is there any evidence of harm? And the answer is simply no. That's why we recommend treating ketogenic therapy like any medical intervention: you follow with your healthcare team, you monitor for safety, you monitor for continued efficacy, and you make sure you're reaching your health goals. You don't have to assume, but there's no evidence to suggest it is harmful. So we can conclude that for those who claim ketosis is dangerous long term, the data simply don't support the claim.
Is ketosis harmful long-term?
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Bottom Line
I'm Dr. Bret Scher. Thank you so much for watching, and we will see you here next time at Metabolic Mind, a nonprofit initiative of Baszucki Group.