The Keto Diet: The Truth Will Set You Free, But...
“The truth will set you free… but first it will piss you off”- Gloria Steinem (Made more famous by Pharrel and Rihanna)
Today I am diving into waters that I have previously ran from like the plague. Whenever I see and hear crazy hype about the newest diet on social media and podcasts, I inherently cringe and want to go hide under a rock. Why? Because I know that I’ll see friends, family members, patients, and random people on the street trying that newest diet, and then asking me if I, too, think that it’s the greatest thing since sliced bread. But as it turns out, I still love bread (slices or otherwise), and today, I feel compelled to write this post. We’re going deep about the ketogenic diet. We’re going to discuss real biochemistry and science. I’m going to cite peer reviewed scientific literature. And most importantly, we’ll discuss, as we always do, how you can practically eat and truly BE healthy in the real world. Here. We. Go.
(If you get lost in the weeds, then skip to the last section for a summary and essential takeaways.)
First, a history lesson
The ketogenic diet (KD) first arrived on the scene in the 1920’s.
Boom! I’m blowing your mind already, whether you want to admit it or not. You thought that “going keto” was just the latest fad. Not true. It has long been researched and validated for improving symptoms in children with epilepsy(1). There are a few theories as to why:
It disrupts cell normal metabolism(1)
It inhibits neurotransmitters which can increase seizure activity(2)
There was a meta-analysis that compared the effect KD, Atkins diet, and calorie restriction on seizure activity. All three showed similar decreases in overall seizure activity. Children have historically been studied because it is easier to control their diets and adherence (unlike adults, who have cars, money, and free-will). There are some theories that any of these dietary approaches may help seizures in adults, but they have not been validated.
At this point, if you don’t have seizures, or are a child, you should be thinking, “I don’t have seizures and I am not a child, and bread is delicious, so why would I want to go keto?” Please continue reading.
Wait, back up. What is ketosis?
Although homo sapiens are the most advanced species on this planet, our cells and physiology haven’t quite caught up to our smart watches. Every cell in our body prefers glucose, which comes from carbohydrates, as a fuel source. It is efficient and can get to our brain and our muscles quickly. When we consume carbohydrates, they get broken down into glucose. In response to this glucose, our bodies will secrete insulin. Insulin is a “storage” hormone. In an ideal world, insulin assists in getting the sugar in our blood stream into target cells - which need this glucose for proper function.
Let’s play a game. We are in the Sahara desert, hunting lions by foot with spears. There aren’t any carbs in sight, and we are running low on fuel. So, our body will pull glycogen, which is stored glucose, from the liver to use for energy. When it eventually runs out of that, we slow way down because we can’t sprint anymore without glucose or gylogen. Our body looks for alternative fuel sources. To do this, we will finally enter into a state called ketosis. The body mobilizes store lipids, converts them into compounds called ketone bodies, which our brain can then use for fuel. To stay conscious and viable, our brain needs constant fuel, preferably glucose. Ketone bodies are like the emergency backup generator that takes a few seconds to kick on when the power goes out, but only has enough power to keep everything dim and flickering like a horror movie. Put simply, the human body evolved the ketotic state as its last ditch resort to stay alive and prevent our brain from dying. This is an expensive process, meaning it takes energy to make energy.
With that context in mind, let’s get specific about what the ketogenic diet typically looks like. It’s intended to deliberately elicit that state of ketosis that we just described (the emergency backup system). To do this, the diet calls for an extremely low percentage of calories from carbohydrates. A very “standard” macronutrient range is about 50% or calories from carbs, 30% from fat, and 20% from protein. A paleo (low carb/high protein) diet may be 30% carbs, 40% fat, and 30% protein. A keto diet is less than 5% carbs, 15-20% protein, and 75-80% fat. You may be asking yourself, “What does <5% of your daily carbs look like in real food form?”, well it looks like about the size of a small banana. For many people, the term keto is now synonymous as “low carb,” but you can see that there is a large range from <5%-30% of daily calories from carbohydrates. Another misconception is that keto is high protein. When followed as it was originally intended (for children with epilepsy), it is actually lower protein than the “standard.” If someone decides to “do keto” but with higher protein, then they are not actually “doing keto” — they’re doing something else that they’ve invented entirely.
One quick but important aside: Ketosis is much different than ketoacidosis. Ketoacidosis is a condition that happens most often in patients with diabetes. Due to problems with their insuline response, blood sugar rises but cannot get into their cells. The cells become starved for glucose because the insulin in their body isn’t working to get glucose into the cell. Under these circumstances, the body will accumulate too much acid, make breathing difficult, eventually progressing if untreated to organ failure, and even coma or even death. This is obviously very serious, but is not the same thing as ketosis, and generally should not happen to you if you are healthy and non-diabetic.
Now that you have a better understanding of what keto is (a huge metabolic shift, that is used in emergency situations), we can move on to the claims of the ketogenic diet. We have established and validated that it is appropriate for use in epilepsy. But diet culture has many other claims, such as:
Preventing and reversing diabetes
Improving heart health
Why do most people try the ketogenic diet? Well, weight loss. At EVOLVE, we don’t really believe in weight loss. We generally don’t weigh people; we frankly don’t care. What we do care very much about, however, are your behaviors. Are you sleeping, moving, managing stress, EATING, and connecting? If you aren’t doing those things, then we should probably address that first and maybe leave the number on the scale behind. Because you, and your health are more than just a number. True health is the result of consistent, positive behaviors, not a specific weight or body composition. Weight can often be a symptom, but is never the root cause, and we are not in the business of treating symptoms.
But, since we’re here talking about keto, let’s pretend to talk about weight loss for a second. One of the claims of the ketogenic diet is that people feel full, FINALLY! They can then lose weight because they don’t feel like they are craving unhealthy snacks all the time.
Why does this happen? Well, keto is a high fat diet. Fat is satiating and actually slows down digestion, keeping you fuller, longer. Many people also eat a higher amount of protein than normal on a keto diet (even if this isn’t technically “keto,” as outlined above), and protein as a satiating effect as well. But here’s the cool part: You can get the satiating effect of fat and protein without going keto! Just add more healthy fats to your diet, such as whole nuts, seeds, avocados, or olives, and see how you feel.
Another potential keto weight loss mechanism is related to water retention. If you search #keto in your Instagram explore or online, you will find a million before and after pictures. It’s PROOF of quick and effortless keto-driven weight loss, right? Well, maybe not. Remember our friend glycogen, the stored form of glucose and source of energy in the body? For every 1 gram of glycogen stored in your body, there are 3 grams of water associated with it. When you severely limit your carbohydrate intake, the body burns through the majority of its gylogency stores, releasing all of that water as well. That means that the 10 pounds that you lose in a week or two is mostly water. Although you may lose weight initially, it is difficult to maintain the KD and once you reintroduce carbohydrates, it is likely that all of that weight and more will come back and possibly more.
Effects of weight cycling
Numerous studies are now showing the surprising effect of weight cycling and yo-yo dieting. Between one and two thirds of of those who lose weight on diets will regain more within four to five years (3). How does this happen? Let’s go back to our hunter-gatherer game on the Sahara. You’re running around trying to find food, but there’s a scarcity. Calories are hard to come by. But humans are crazy resilient, and so our physiology has figured out a way to help you survive. When it senses that you are in famine or in a state of restricted calories, it does its best to conserve energy. It will do this by reducing our resting metabolic rate. Your body reacts automatically to calorie restriction by slowing down our metabolism, meaning that you will be “burning less” at rest. Fast forward to the modern world, and our body hasn’t yet figured out the difference between a famine and the latest fad diet. Going on and off restrictive diet can have severe metabolic consequences that make it easier to gain weight and harder to lose it in the future — the opposite of what you probably want if you’re trying these diets. Repeatedly gaining and losing weight also linked to an increased risk of cardiovascular disease, stroke, diabetes, decreased immunity, and higher rates of mortality (4). Dieting is also very isolating. It dissociates us from our family, community and normal life. Because who wants a keto birthday cake?
So moral of the story: If that latest diet isn’t one that you really, truly think you can make your long term lifestyle, then it’s probably not the best for you. You know what fad diet is incredibly hard to maintain over the long term? You guessed it. Starts with a K and rhymes with “Frito.”
Who is this effect of weight cycling a really big problem for? Well, women. Women are constantly being told by the media, our culture, and social media that we should look differently than we do. We should lose weight, gain muscle, get more toned, and the list goes on. Women are more likely to be exposed to and buy-in to diet culture. In a recent study conducted in 2012 of young adult women (18-35 years old), 75.6% of women were either trying to lose weight (43.4%), or actively trying to avoid gaining weight (32.3%) (5). This is a huge problem because dieting is not benign and keto is definitely not benign. For a longer discussion on the negative effects of diet culture, see my previous article on orthorexia.
Keto and hormones
The keto diet can have a significant impact on our hormone expression as well, and not necessarily a positive one, especially for women.
As a female, our body’s primary physiological goal is survive in order to procreate (as a feminist, I disagree with this, but hey…. evolution). The complex ebb and flow of hormones throughout the month is all geared around childbirth. When we lose weight, the body thinks that something is wrong, and goes into a stress response (remember, that response that tells us that we are in famine). If this state is continued on an ongoing basis, the stress response will increase, and the body will begin to take bigger measures to protect itself. The body’s logic is that you can’t make a baby if you’re starving, as pregnancy takes a tremendous amount of resources. So, it dedicates resources to take care of the first problem before worrying about pregnancy. Hormone expression changes to make pregnancy nearly impossible. Even if you don’t want to have a baby right now, you should still see this as a BIG problem, because your normal physiology and health depends on normal hormone cycles. You can think of hormones as a symphony, if one person is off tune or late to come in, then the whole ensemble suffers. Altered hormones will cause a cascade effect and this can effect our hunger, satiety, sleep, menstrual cycles 6, and well, everything else. One of these stress pathways will increase cortisol, a hormone which will raise glucose, and cause many problems when it is elevated chronically. In a nutshell, keto stresses our bodies out, and that stress response affects our hormones. If you are trying to get pregnant, it may have a drastic effect on your hormones that will make it more difficult. But, hormones control everything our body does and if they start to get wonky…. everything gets wonky, for both males and females.
Keto and heart health
“What about the claims about it improving my cholesterol and heart health?” Good question! We no longer think that fats are bad (thanks to the sugar industry for the crappy low-fat research). There seems to be some short term improvement in triglyceride levels and maybe and increase in HDL (the good stuff), but there was a recent study that also indicated an elevated in LDL (the not so good guy) on a ketogenic diet (7). High levels of LDL cholesterol are associated with higher rates of cardiac disease. But, there are no long-term research on cholesterol levels and keto, mainly because large groups of people cannot sustain this diet for multiple years.
What we do know (from a lot of very, very good research) is that a high fiber diet rich in soluble fibers, which come from fruits, vegetables, and whole grains decreases cholesterol levels and improves heart health (8). Cardiovascular disease is an overall inflammatory disease that is complex in nature, but there are exponentially more studies showing the anti inflammatory benefits of eating foods that are high in antioxidants (such as colorful fruits and vegetables). Any new research study must be interpreted within the context of the greater body of scientific literature. There are countless studies showing how to reduce cardiovascular disease risk and promote healthy cholesterol levels with balanced, inclusive diets and other positive lifestyle behaviors. A handful of small studies about potentially benefits of keto should not cause us to toss what is already known, proven, and established out the window. And any diet or approach to eating must also be evaluated by how sustainable it can be for a person — and keto is hard to maintain due to the severe carbohydrate limitations it imposes.
Keto and gut health
Let’s keep going. The gut-brain-axis (GBA) is being shown to have a significant impact on mental health, and vice versa (9). Our guts are comprised of a number of bacteria, hormones and neurotransmitters. The foods that we eat impact the balance of our bacteria in our gastrointestinal tract. High fiber foods (fruits, whole grains, vegetables, nuts and seeds) are not completely broken down by our gastrointestinal tract, and whatever is left over will be broken down by our gut bacteria. Fiber is bacteria’s food, also known as prebiotics. Probiotics are the actual bacteria that is found in your gut and fermented foods such as yogurt, kefir, kimchi, and kombucha. Your beneficial bacteria cannot thrive without fiber or prebiotics. High fat and high meat diets - which is often how people follow the keto diet - are associated with increasing intestinal inflammation and decreasing beneficial bacteria. This has correlated with higher rates of insulin resistance and inflammation (10). High fat and high meat diets are also associated with higher risks of colon cancer, so if you have a family history of colon cancer, you may want to try a higher fiber diet (11).
Keto, blood sugar, and diabetes
Diabetes is a chronic, inflammatory disease that occurs because our body either does not produce enough insulin or doesn’t respond well to the insulin that we are secreting. Remember at the beginning of the article, insulin is produced in response to glucose. So theoretically, you would assume, “get rid of carbs, and I don’t have to worry about it, right?” Well… not so much.
Because our bodies are really good at trying to stay alive, research has shown that even non-diabetics on the ketogenic diet may have higher fasting blood glucose compared to controls. That means that there is more glucose floating around in your bloodstream. A higher fasting blood glucose, can increase your hemoglobin A1c (how much sugar is bound to red blood cells), which is an indicator of type 2 diabetes. How does this happen? Two potential mechanisms: 1) Your body is trying to mobilize all of the glucose it can muster because it feels a consistent glucose restriction, and so this ends up getting into the bloodstream at a greater extent than those who consistently eat sufficient carbohydrates. 2) Remember our friend cortisol, released as part of the body’s stress response? Cortisol increases blood sugar, and if keto is stressing your body out, you’ll have more cortisol and thus a potentially higher blood sugar. Weight cycling is also correlated with decreasing insulin sensitivity, which increases your risk for type 2 diabetes (4). Please keep in mind that the opposite of the ketogenic diet is not a plate of french fries, donuts, and Frosted Flakes. What I am saying is that whole grains, a few servings of fruit per day, high fiber vegetables, and lean proteins are all a part of a healthy diet, for those with and without diabetes. Again, there are no long-term studies that show the long-term effects of a ketogenic diet, probably because people can’t adhere to it in the real world.
Keto and endurance athletes
Alright, alright “But what about those ultra endurance mountain runners?”. There actually is some really compelling research that fat adapted ultra-endurance runners (running a distance more than 26.2 miles, often on trails or up a mountain ) will oxidize more fat than those who are not fat adapted (12). Duh - these folks are training their bodies to be really efficient. But does that mean they perform better? I don’t know. Someone should design a study — but it hasn’t been shown thus far.
Let’s return one final time to the Sahara, where we have limited glucose. We have a ton of energy stored in our body fat, and if we can mobilize that, we can go forever right? Well, maybe. But the process to efficiently mobilize this body fat, called fat adaptation, is a bit long and painful. It can initially take 6-10 weeks for your body to adjust, then it can take your body about a year or two to really get your body efficient. That means that in the meantime, you shouldn’t be consuming carbs in the meantime and flip-flopping back and forth, as this will reset you out of ketosis. Say bye to birthday cake, cookies, electrolyte drinks (often essential for distance runners), and beer (ultra runners BFF). Did we mention this diet is really hard to maintain?
And even if this keto is effective in a small percentage the athletic population, but what about everyone else? Probably not ideal. There are a few energy systems that generate power and force in the body (that I won’t go into detail on because I’m already rambling). But with the exception of the low intensity aerobic system, they all function on carbs. So, if you need to do anything else than just trudge at a low pace for a really long time (ultra running), like sprint, jump, climb, or anything else, then your body will function MUCH better with a consistent flow of energy (carbs) (13).
Finally, remember that fat is satiating because it slows down our digestion. Keto is a high fat diet by definition. So when you are running or biking, your digestion rate is already slowed because digestion takes a lot of blood, which is being sent to your muscles and heart instead. It will then be pretty dang difficult to process all of the fat you need on a keto diet, which can contribute to GI distress. You can read more about this in my article about gastrointestinal issues and the athlete. Muscle may also start to break itself down because your body is searching for a way to make glucose, this means that your #gainz will probably be diminished. Please note, I am not promoting the low-fat diet nonsense. A low fat diet is also not the opposite of keto. We should probably eat more fat, like nuts, seeds, and good oils.
The ketogenic diet is most likely not ideal for females, athletes, diabetics, those with cardiac disease or a family history, or those with a history of colon cancer. It also might not be beneficial for those with mental health disorders because it may affect the gut microbiome. There still needs to be more research here. Lastly, we should stop weight cycling and dieting. It is actually harmful to us mentally and physically.
Lastly, there are a lot of genes that make up who we are and how our body functions. Our genes get to decide how we metabolize food, substances, and basically write our life story. The ketogenic diet may work really well for those who process fats really well, and don’t process carbs well. Unfortunately, there aren’t many tests out there (yet) that can tell us this, and they are really expensive.
Let’s wrap this up. Read this even if you’ve skimmed everything else!
We have discovered that there needs to be A LOT more research done to determine the benefits or lack there-of for the ketogenic diet. A lot of the REALLY big proponents online of the ketogenic diet are people who do not have a nutrition or a science background. Know where you are getting your information. The ketogenic diet is likely not ideal for most females, athletes, diabetics, those with cardiac disease or a family history of heart problems, or those with a family history of colon cancer. It may not be great for those with mental health issues due to the brain-gut connection. And for anyone who doesn’t think they can sustain it for a long period of time (years and years) — also not ideal due to the potential for weight cycling and metabolic shifts. The ketogenic diet may be appropriate for males who are comfortable with a rigid dietary regimen. Lastly, there are a lot of genes that make up who we are and how our body functions. Our genes get to decide how we metabolize food, substances, and basically write our life story. The ketogenic diet may work really well for those who have specific genes that allow them to process fats really well, and genes that inhibit the processing of carbohydrates. Unfortunately, there aren’t many tests out there (yet) that can tell us this, and they are really expensive.
Finally it, is so, so important to look at the weight of scientific evidence, and consider any individual study in the context of this bigger picture. Research has time and time again proven that eating vegetables, fruits, lean proteins, and healthy fats from nuts, seeds, olives, and the like. This stuff isn’t sexy. But it works, and it can be sustainable throughout a lifetime. The keto diet, or really whatever the next restrictive, rule-based diet is, violate basic principles of sustainable behavior change. Even if science told us that going keto was as good or better than an inclusive, balanced diet, it still probably wouldn’t be my top recommendation because it’s focus is all wrong. It focuses on what you can’t have, rather than what you can. Why go down that road? Why not learn how to eat intuitively, find balance and joy in food, and a positive relationship to your body and your food?
What we would focus on instead is eating. Eating mostly vegetables, with lean proteins and high fiber legumes, fruits, and whole grains. Oh, and leave some room for those things that make you happy like the occasional cake or donut. Because we eat for more than nutrition. Food should also bring us pleasure, and connect us, rather than alienate us. We should focus on moving our bodies in ways that make us feel good. We should do this often, daily if possible. We should sleep and rest because we live in a stressful place, and the ketogenic diet may actually put more stress on our bodies, and who needs that? We should also connect. Connect with ourselves and our community. Dietiting is inherently dissociating, not associating. It tells us to ignore hunger, that eating is bad, that cheating is okay. This alienates us from ourselves, our families, and communities. Let’s all working on being more human instead of lab rats.
If you have questions about keto or really anything else nutrition related, schedule a time to chat with Abby.
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