4 Reasons A Keto Diet Is Bad For Your Health

September 28, 2017 By coleadam21 15 Comments

Every couple of years a new low-carbohydrate (low-carb) fad diet pops up and rears its ugly head. First it was the Atkins diet. Then the South Beach and Zone diets sprouted up. Today, we have the paleo and whole 30 diet. But there’s a new kid on the low-carb block—the keto or ketogenic diet.

The keto diet is a high-fat, high-ish protein, and extremely low-carb diet. Along with other low-carb diets, meat, eggs, seafood, oils, and high-fat dairy products like cheese and butter provide the majority of calories. Nuts and low-carb vegetables are also included, but higher-carb vegetables, fruit, potatoes, grains, and beans are excluded, or severely limited. This type of diet is meant to induce a metabolic state called “ketosis”, in which the body is depleted of glucose (carbohydrate) and glycogen (the storage form of glucose). In the absence of glucose, the body produces ketone bodies, which it uses for fuel.

This diet is occasionally used to treat epilepsy in children who aren’t responding to therapy, but it’s often considered a last resort. However, the recent spike in interest over the keto diet isn’t from epileptic children, but from people looking to lose weight and improve their overall health. A quick Google search directs you to numerous websites touting a long list of benefits that you’ll experience if you adopt a keto diet. These claims, which are often mentioned without any supporting study or link, include: weight loss, improved diabetic control, improved mental focus, increased energy, improved cholesterol levels, better skin, improved gastrointestinal health, reduced sugar cravings, improved blood pressure, migraine control, improved heartburn, reduced ADHD symptoms, and it is even mentioned as a treatment for polycystic ovarian syndrome and brain cancer.

Sound too good to be true? That’s because it is. All of these claims are either blatantly false, misleading, or true but come at the expense of our overall health. And most of us would never know this if we just scanned the top layer of these websites. But when we get our hands deep into the data, it becomes quite clear that a keto diet is not ideal for human health and is hazardous to our long-term health.

When I reviewed the data, I only found a few (non-epilepsy) studies looking specifically at a keto diet. There are, however, a fair amount of studies looking at low-carb diets, which is essentially what the keto diet is. In fact, many of the pro-keto websites I reviewed use low-carb diet studies to support their claims. The problem with many of these studies is that they were funded by the Atkins Diet Foundation, or some other organization that is financially benefiting from low-carb diets/products/books/etc. These studies are designed to produce favorable results, which are then used to market and sell their fad diet and products. There is an obvious conflict of interest at play.

So, just like we wouldn’t use tobacco industry studies to decide if cigarettes are healthy, or egg industry studies to determine if eggs are healthy, we’re not going to use these biased studies when looking at the health implications of a low-carb diet (although I did still review these). When we exclude biased studies, we’re still left with a good amount of data. Based on that data, here are my top four reasons we should avoid a keto diet.

1. It Is The Opposite Of What We Should Be Eating For Ideal Health

Because of its high-fat, higher-protein, and low-carb nature, a keto diet is typically centered on animal products. Meat, high-fat dairy, eggs, seafood, and oil tend to provide the majority of calories, while higher-carb vegetables, fruit, beans, and grains are excluded or severely limited.

This type of diet is the complete opposite of what the overall evidence on diet and nutrition suggests we should be eating. The data is quite clear that humans should consume a diet of primarily, or entirely, unprocessed, plant-based foods. We should center our diet on the exact foods that are avoided while on a keto diet. Whole grains, beans, fruits and vegetables should provide the majority of our calories, whereas high-fat animal products should be limited or avoided.

This message is echoed by all major health organizations, from The American Cancer Society to the World Health Organization. Eating a predominantly plant-based diet was also the main focus of the 2015 Scientific Advisory Committee’s recommendations for the USDA food guidelines (before the food industry flexed its muscle).

It comes with no surprise that all of the healthiest, longest-living populations in the world consume a diet that is nearly the exact opposite of a keto diet. People living in “Blue Zones” (a term coined by National Geographic’s Dan Buettner to describe places in the world where people tend to live the healthiest and longest lives) all eat a diet rich in unprocessed, high-carbohydrate foods, such as beans, whole grains, potatoes, fruits, and vegetables. In fact, high-carb sweet potatoes provide two-thirds of the calories in the traditional diet of Okinawa, Japan—a place that boasts the longest life expectancy for women.

Regardless of how many pro-keto websites tell us that “we got it all wrong” when it comes to nutrition, we didn’t, and we still don’t. The overall message that we should eat a diet centered on unprocessed plants while limiting animal products and processed foods has been the mainstay of nutrition recommendations for decades. Diets rich in unprocessed plant-based foods are consistently and overwhelmingly associated with better health and a longer life, while diets centered on animal products and devoid of fruit, whole grains, and beans, are consistently and overwhelmingly associated with chronic diseases and premature death.

Many of the foods avoided on a keto diet are the exact foods we should be eating for ideal health and longevity. Beans are the food most associated with healthy ageing, while whole grains are consistently associated with lower rates of death and chronic disease (1-2). A lack of fruit in our diet is one of the most prominent dietary risk factors contributing to our global disease burden (3). These foods shouldn’t be avoided, but encouraged. Anyone who says otherwise is not referencing evidence-based information and has a severe lack of insight on the overall data as it pertains to human health and nutrition.

2. You’ll Lose Weight…But It Won’t Last

People tend to initially lose weight on a low-carb diet, whether it be a keto diet, Atkins diet, or whole 30 diet. In fact, people tend to lose weight very rapidly on a low-carb diet. But there’s a catch.

A majority of the initial weight loss is a reflection of water loss, not fat loss. When we stop eating glucose (carbohydrate) we eventually deplete our body of its glucose stores (called glycogen). Glycogen is bound to water, so when we burn through stored glycogen, we shed and excrete the water it was bound to. This makes a big difference on the scale, as one liter of water weighs 2.2 pounds. I’ve weighed myself before and after playing a couple hours of outdoor basketball on a hot day and I can easily drop five pounds in two hours by simply sweating off water. Knowing that it’s water weight, I’ll obviously rehydrate and gain that weight back, but people on low-carb diets see that initial, rapid weight loss and mistake it for fat loss.

After the initial loss in water weight, the weight loss that follows is typically the result of a reduced calorie intake. Although there are some exceptions, weight balance is determined by calorie balance. In other words, if you consume more calories than you burn, you’ll gain weight. And if you consume fewer calories than you burn, you’ll lose weight. People on a keto diet tend to reduce the number of calories they consume for a variety of reasons: The high-fat meals have a satiating effect, sugary foods and beverages are avoided (think candy bars and soda), feelings of nausea, loss of appetite, or malaise set it, or because the diet itself is extremely restrictive. Each of these, and/or the combination, work to lower total calorie intake, which will result in weight loss.

Anytime calories are reduced below your metabolic needs, you’ll lose weight. This holds true regardless of what you’re actually eating. To prove this point, a nutrition professor at Kansas State University went on a “Twinkie diet” that consisted of Little Debbie snacks, Doritos, Oreos, and other junk food. He kept his caloric intake, however, around 1,800 calories per day—about 1,000 calories less than he metabolically needed to maintain weight. And sure enough, after two months he had lost 27 pounds. All weight loss diets work in a similar fashion—they get people to eat fewer calories. The most important question, however, is whether a low-carb diet is more effective than other weight loss diets?

Many studies compare low-carb diets to low-fat or other calorie-restricted diets and find that low-carb diets result in more initial weight loss. The problem is, these studies tend to last only a few weeks or months. Given what we know about the rapid water loss on low-carb diets, this isn’t a surprise (those who financially benefit from low-carb diets know this and design studies to exploit it). In fact, most low-carb weight loss studies rarely reach one year in duration. The studies that do last more than a year, overwhelmingly show that low-carb diets do not result in any more long-term weight loss, compared to other weight loss diets (even studies funded by the Atkins Foundation fail to show any advantage of their diet over the long term) (4-11). I should point out, however, that most “diets” don’t lead to long-term weight loss. And the keto diet is no exception.

People who go on low-carb diets rarely stick to them. And many find themselves going on and off these diets with their weight yo-yoing as a result. This cycle of weight gain and weight loss is not good for our health. It slows down our metabolism and makes future weight loss that much harder. If you are looking to break the vicious cycle of on/off dieting, I would encourage you to read the book “The End of Dieting” by Dr. Joel Fuhrman, M.D.

Low-carb diets, including the keto diet, lead to a rapid loss in water weight. Any further weight loss is the result of calorie restriction, not some low-carb magic. Do not be fooled by studies that boast greater weight loss with low-carb diets, as these are typically conducted over a short duration. Long-term studies show that low-carb diets are no better than any other calorie-restricted weight loss diet (although most “diets” are not effective over the long term). Just like the “Twinkie diet”, a low-carb diet can lead to weight loss if calories are kept in check, but neither are preferred for long-term, overall health.

3. There Are Many Potential Negative Side Effects

A healthy diet should improve our health and make us feel better. This doesn’t appear to be the case with a keto diet. Websites profiting off a keto diet are more than willing to share individual testimonies about how the diet helped someone lose weight and feel great. It’s hard to dispute these anecdotal reports. But I’ve also reviewed every study on a keto or low-carb diet that I could get my hands on and found that many people who are placed on such a diet experience a variety of negative side effects. In some studies, unwanted side effects were reported in over 50% of participants following a keto diet (12). Even pro-keto websites acknowledge the following side effects, which include:

Headache
Constipation
Diarrhea
Insomnia
Back pain
Kidney stones
Increased calcium loss
Heart palpations
Flu-like symptoms
Foul-smelling breath

Another unwanted side effect reported in some studies, is an increase in LDL (bad) cholesterol levels. Typically, when someone loses weight, regardless of how (drug addiction, cancer, starvation), their cholesterol levels tend to improve. This happened in the Kansas State professor who went on the “Twinkie diet”. Because he lost weight, despite his junk food diet, his LDL cholesterol dropped by 20%, HDL (good) cholesterol increased by 20%, and his triglycerides decreased by 39%. This same effect occurred in a few of the weight loss studies, but others showed that a low-carb diet negates the cholesterol-improving effect seen with weight loss, especially when compared to a low-fat diet (12-17). In some instances, participants on a low-carb diet needed to increase their cholesterol medication or start taking a cholesterol-lower drug (13; 15). The goal of a healthy diet should be to reduce the amount of medication needed, not increase it.

On top of this, low-carb diets have been shown to impair blood flow, which is not what any of us want, but especially people with a history of, or at risk for, cardiovascular disease (18-20). With the ability to negate weight loss-induced improvements in cholesterol, while impairing blood flow, it’s no surprise that low-carb diets have been linked to an increased risk of cardiovascular disease (21).

Another potential long-term side effect is an increased risk of cancer. Not only does a keto diet limit or avoid foods that are known to help protect against cancer, such as fruit, whole grains, and beans, but the diet’s high amount of animal protein may increase our cancer risk by increasing something called insulin-like growth factor 1 (IGF-1). IGF-1 appears to play a role in the development of cancer, metastasis of cancer, and may even protect cancer cells from anti-cancer treatments (18). Having higher levels of IGF-1 is associated with an increased risk of numerous cancers, including breast and prostate (19-23). Studies show that diets rich in animal protein boosts IGF-1 levels, while consuming your protein from plants is associated with significantly lower levels (24-30). The increase in IGF-1 caused by animal protein is likely one of the many reasons the American Cancer Society encourages people to eat a diet that emphasizes plants, such as whole grains, fruit, vegetables, and beans, while avoiding red and processed meat. Again, the opposite of a keto diet.

4. A Keto Diet May Shorten Your Lifespan

Remember those healthy, long-living “Blue Zone” populations thriving on a diet rich in whole grains, fruit, vegetables, and beans—a diet that is almost the complete opposite of a keto diet? It should come as no surprise then that following a low-carb, keto-like diet is consistently associated with increased mortality (31-35). In other words, long-term adherence to a low-carb diet appears to increase one’s risk of premature death. Many of these studies also show that low-carb diets based on animal products are positively associated with death and disease, while diets based on plants, whether lower in carbs or not, are negatively associated with death and disease (31; 35-38).

This is my main concern with animal-based, low-carb diets. They sacrifice our long-term health for perceived short-term improvements that tend to not last. As Dr. Michael Greger, M.D. has bluntly pointed out: low-carb diets are great…if you want a skinnier casket.

Summary

The keto diet has become the fad diet du jour. Its mechanisms of action and supportive arguments are nothing new, as they are simply a regurgitation of the original low-carb Atkins diet. Do not be fooled by the “quick-fix” nature of this diet. Its superficial short-term benefits rarely last and come at the expense of our overall and long-term health. Instead, stick to a diet that is supported by the overall evidence and consumed by the healthiest, longest-living populations on earth—a diet rich in unprocessed, plant-based foods, such as whole grains, beans, fruit, vegetables, nuts and seeds.

Peace, Love, Health

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Comments

Laura says

January 9, 2018 at 7:07 pm

Thank you for this! All of the good media for keto has had me seething… I wish more people would understand the negative implications of this diet, and weren’t so impressionable 🙁

Reply
- coleadam21 says
  
  January 9, 2018 at 11:07 pm
  
  You’re welcome! I totally agree. I don’t know if the low-carb fad diets will ever go away.
  
  Reply
Steven says

February 28, 2018 at 2:21 pm

Thank you for this! As a vegan it really makes my blood boil when I see pushers of this dangerous diet

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Lisa Jones says

March 5, 2018 at 5:47 pm

AMEN! I found this on page 18 on a Google search “will the Keto Diet kill you?”. My point and your point in this article proven completely… I personally know a very good man that died from the Atkin’s Diet. He lost 300 pounds then promptly passed away from a massive heart attack. He was the smartest, kindest man. The world lost a card holding Mensa member to a FAD DIET! That is how strong the human desire is to look past truth for immediate results.

Reply
Gary says

April 23, 2018 at 1:27 pm

I have been on a ketogenic diet for almost 2 years. But unlike the “classic” high animal protein keto diet, mine is high natural fats (avocado, EVOO, nuts), low in animal protein (mainly wild seafood). Typically macros 75% plant fats, 15% protein, < 10% carbs very nutrient dense foods ensuring I get full amino acid profile. I eat NO animal protein other than seafood, no dairy, no sugar, no fruits. And I keep my protein intake low, 0.8 g/kg body mass, simply sufficient to maintain muscle mass and deliver the essential amino acids for good metabolic health. I also exercise 7 days/week, 4 miles aerobic + 45 minutes resistance. My cardio health (echo, stress test) is "athlete" level. My insulin and blood glucose are very low, along with IGF-1 (these are 3 KEY mortality biomarkers re mTOR activation). I have lost over 50 lbs, BMI down to around 23.

The daily dietary requirement for carbs is…ZERO. Body makes all the glucose it needs from fats/proteins. We evolved on plants, protein, fats. Carbs are a modern day invention (last 10,000 yrs). I think the longevity of the blue zones is partly low animal protein intake, and largely genetic narrow haplotypes that have selected for longevity.

So there are other NON-ATKINS-paleo ketogenic pathways out there that deliver (based on my regularly tested biomarkers) excellent metabolic health.

Reply
- coleadam21 says
  
  April 23, 2018 at 1:57 pm
  
  Thanks for your insight, Gary. You are an exception, as most people following a keto diet are eating mainly animal products, which is largely responsible for it’s deleterious health implications. This post was written in that context, not in the context of a largely plant-based low-carb diet. There have been two studies that have looked at an “eco-atkins”, or plant-based low-carb diet, and found favorable metabolic changes, but more research is needed looking into this kind of diet and comparing it to a high complex carb, low-fat, plant-based diet, which is the only diet proven to reverse heart disease, our leading cause of death. The body can make glucose from fat/protein, but does that mean getting it from our diet is bad? No. Carbs are not a modern day invention. Fruit, a food that is mostly carbohydrate, has been part of the human diet for our entire evolutionary history and has well established health benefits.
  
  Reply
Renee says

July 24, 2018 at 12:00 am

I started keto in November to see if it would heal my epilepsy and I have experienced the most incredible side effects of a clear focused mind, vitality and diminished anxiety, all after years of eating what is supposed to be an incredibly healthy diet. If keto is unhealthy then i would rather be unhealthy and feel good. Oh, and I used to not be able to go 4 hours without eating or I would get very sick, now I can go all day if I need to and after a life of cripplingly painful menstral cramps, I no longer have pain. None of that is a placebo effect because I was simply trying to find a way to naturally reduce my seizures, the rest were pleasantly surprising added bonuses.

Reply
- coleadam21 says
  
  July 24, 2018 at 4:17 pm
  
  Did you read the post? There may be some benefit in people with epilepsy, but it’s not idea for our overall, long-term health. If people with epilepsy want to try a ketogenic diet, I would encourage a plant-based version.
  
  Reply
  - Renee says
    
    July 24, 2018 at 6:06 pm
    
    Yeah I read it. Claims were made about keto being highish in protein, which it actually isn’t, and that keto is always a last resort for kids, as though it is a last resort due to it being unhealthy. It’s typically a last resort because it is a difficult diet to follow, obviously it would be better to not have to be on medications for the rest of ones life. And I have read on some epilepsy websites that the only reason its not prescribed to adults is because adults have even a harder time following it. Sadly it seems as though adults are more motivated by weight loss than they are health, so people seem to find it easier to stick to to lose weight than to reduce seizures and be off medication. Keto is relatively knew in terms of using for healing purposes other than curing epilepsy so it’s kind of unchartered waters. My friends mom has breast cancer and her doctor has her on a keto diet.
    
    Keto has been incredibly life changing for me, for years my daily diet has been plenty of organic veggies, a sweet potato every day, whole grains (I even hand grind my own flour-einkorn flour) and legumes. And I have had blood sugar problems and anxiety and never feel quite well after eating. Now I eat meat veggies and cheese, and nuts, and lots of fats, butter, olive oil coconut oil, ghee, avocado oil, and I finally feel well.
    
    I’m not saying that that means that the standard idea of healthy eating is wrong, but obviously keto is good for me, and there are societies of people, like inuits, who thrive off of it, so obviously we are all different and health isn’t a one size fits all approach. It’s not low carb diets that are the problem, it’s the obsession that people have with looks and weight loss that is the problem.
    
    Reply
    - Renee says
      
      July 24, 2018 at 6:08 pm
      
      Hmm, I didn’t realize that my picture would be shown, I wanted to be anonymous lol
      
      Reply
    - coleadam21 says
      
      July 24, 2018 at 7:07 pm
      
      Opinions, personal testimonies, and friend’s moms, don’t change the fact that the peer-review, independently-funded scientific evidence suggests that a ketogenic diet based on animal products and animal fats is detrimental to our long-term and overall health. Humans are well adapted to survive on many types of extreme diets, and often do so by necessity, not by choice. The idea that the Inuit were/are thriving on this diet has long been proven untrue, as they suffer from just as much chronic disease and premature death as typical Western populations eating the typical Western diet.
      
      My goal with this blog/post is to present the data so that people may make their own informed choices. I would encourage you to review the research I’ve shared in the post, especially the studies suggesting increased overall mortality from a low-carb diet, as well as the role animal protein plays in boosting IGF-1 levels, which has been shown to promote cancer growth and progression.
      
      Reply
      - Renee says
        
        July 24, 2018 at 7:26 pm
        
        I would be interested in seeing the study showing that inuits have the same health problems as what is suffered in the west. I don’t see it in your references. My understanding is that a lot of younger generations who are adopting a western diet are seeing the same health problems.I’m not trying to be confrontational, my skin just prickles at the one size fits all diet approach, probably just as much as yours does the low carb diet approach. and I saw this post shared on facebook so wanted to share my experience because it has sure been good for me. Also, I just took a nutrition class in school and they are still touting the, cholesterol is bad for you idea, so I dont have a lot of faith in the paradigm that nutritional science is in at the moment
      - coleadam21 says
        
        July 24, 2018 at 8:01 pm
        
        I appreciate your sincerity. We all are vulnerable to confirmation bias when it comes to nutrition. I would encourage you, as someone interested in nutrition, to do your own research and approach nutrition topics with an unbiased state of mind. If you’re curious about a nutrition topic, go directly to the research and bypass websites, blogs (even this one), and other filtered nutrition outlets. Every nutrition claim should be back with a non-industry funded study/studies (which sometimes takes some digging). The reason I go to all the trouble to attach links to all the studies at the bottom of each post, is so that people can fact-check my claims and go directly to the source. Another website that I think does a good job of this is nutritionfacts.org (see link below), as you can find the exact study referenced.
        
        Regarding the Inuit health issue, see the link below. Again, the evidence clearly and consistently suggests that a diet centered on whole, plant-based foods is ideal for human health. There are some small variations and exceptions with certain foods/nutrients (celiac disease, lactose tolerance, food allergies, etc), but that doesn’t change the overarching theme. For the record, cholesterol is definitely not good for us (nor necessary in our diet). The recent push behind the “cholesterol is good/harmless” concept is fueled by the egg industry and fads diets heavy in animal products. They say the best lies are the ones with a little truth. This is a perfect example. Although dietary cholesterol is not as detrimental as saturated or trans fat, that by no means makes it healthy or harmless. See my post “Are Eggs Healthy?” for more information. https://nutritionfacts.org/2018/07/12/the-eskimo-myth/
Yury says

September 26, 2018 at 9:42 pm

This article shows you dont truly understand the keto diet. The keto diet is NOT primarily an animal products diet and is NOT a “high-ish” protein diet as you stated. Most people on a modern keto diet consume mostly non-starchy vegetables (the recommendation is 7-10 cups) with a moderate intake of protein, moderate fruit intake, and moderate animal product intake. Also, it has nothing to do with caloric restriction; many people on the keto diet actually consume MORE than they’re metabolically meant to eat and they still manage to shed the pounds.

You stated Gary’s situation above is the exception, but that is actually what a proper keto diet sounds like. Many of the studies that you cited aren’t true ketogenic studies since either the corbodyrate intake was more than 5% of the diet or the protein intake was much too hig. It’s important to stay at a moderate protein level in order to stay in ketosis, therefore a higher protein intake or high animal fat intake would actually kick you out of ketosis. It’s unfair to group the keto diet along with all the other low-carb diets as you’ve done in this article, since being in ketosis offers a unique set of benefits that other low carb diets like the paleo diet and Atkins diets just don’t. Please review your research again and you’ll see you still have quite a bit to learn about the keto diet 🙂

Also, please research the effect of insulin on our bodies, health, and the impact it has had on obesity and nutrition in modern society. You didn’t mention the insulin effect at all in this article and this is one of the main reasons keto is so effective for health and weight loss in general – studies show that elevated insulin levels are the cause of most modern disease, and the keto diet is one of the most effective diet that keeps these insulin levels consistently low and improves insulin sensitivity in most, if not all, participants.

Reply
- coleadam21 says
  
  September 26, 2018 at 11:42 pm
  
  I don’t think you understand the basic principles of ketosis. You’re unlikely to achieve ketotsis with “moderate” fruit intake, as you have stated. Higher animal fat intake would not “kick you out” of ketosis, as you have stated. A high-fat diet is the basis of the keto diet. The long-term weight loss has everything to do with calorie restriction. I fear you are beyond convincing, but wish you well. As Dr. David Katz of Yale University Prevention Research Center put it, “As for those peddling the concept of ketogenic diets so absurdly beyond the basis for it in any evidence, there are only two explanations. Either they have drunk deeply of their own low-carb Kool-Aid, and are themselves deluded; or they are selling the stuff to you, but know not to buy it, in which case they are profiteering hypocrites.” Link: https://www.huffingtonpost.com/entry/toasting-2017-goodbye-with-ketogenic-kool-aid_us_5a44f4cae4b06cd2bd03de4f
  
  Reply

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