The Screaming Viking is a former athlete, SwimSwam contributor, and coach who has long advocated the ketogenic diet. He wrote a 7-part series for SwimSwam several years ago entitled “The Viking Manifesto” (1, 2, 3, 4, 5, 6, 7) in which he claimed that the ketogenic diet along with USRPT might cause optimal adaptation for racing. He even went so far as to experiment on himself by returning to the pool after an 18 year hiatus to prove it’s worth. With the recent Gold Medal Mel episode revealing Michael Andrew’s experimentation with the Ketogenic diet, SwimSwam invited the Viking to give readers a brief break-down of exactly what it means to “go Keto” and to address some of the common questions that arise when the diet comes up in discussion.
Since Michael Andrew let the cat out of the bag about his use of the ketogenic diet, you will probably hear “keto” come up a lot more often on the pool deck. There is a lot of confusion surrounding the ketogenic diet so the SwimSwam staff decided we should take some time to bring people up to speed on the basics. Keep in mind that this article is not intended to endorse a ketogenic diet. We just want to make readers aware of both sides of the argument on whether this is a healthy choice or not, and give you some insight into why it can be a controversial topic. Hopefully, this article can serve as a starting point in your research and give you a basic vocabulary to have further conversations.
Please note: Shawn Klosterman is not a medical doctor, nor is anybody at SwimSwam. Do not take this as medical advice. Consult your doctor before starting any new diet.
What is keto? The ketogenic diet is similar to the Atkins diet in that it is essentially just “low-carb” and is often also called LCHF for “low-carbohydrate, high-fat.” The idea behind it is that if we lower our supply of glucose from food far enough, our body is capable of flipping the switch toward burning fat as a fuel source to replace it. It is as simple as that. The ketogenic diet can be quite a controversial topic though, as food can often be tied to our belief systems and people tend to take a stance on the “right” or “wrong” way to eat. The advice keto proponents suggest often flies in the face of conventional wisdom, national nutrition guidelines, and most likely even the advice of your family doctor. Even more controversial is that there are so many anecdotal claims of healing from all sorts of chronic diseases with a ketogenic diet, yet very little scientific data to back up those claims. It doesn’t help that there is also a lot of conflicting science out there when you start down the rabbit hole looking for answers. Nutrition studies are difficult and expensive, which can open the door to manipulation. Once you take an interest in searching for the truth on what to eat, you will start to realize that nutrition science has some issues that need to be worked out and that a lot more avenues need to be explored through high quality research.
What can one eat and what must one avoid in a ketogenic diet? Essentially, someone following a ketogenic diet is trying to avoid blood glucose spikes and the insulin surge that follows them. That means that sugar, and all of the carbohydrate foods that eventually become glucose in the bloodstream, are forbidden. Some sources recommend staying below 50 grams of carbohydrate per day, while others recommend as low as 20 grams, which can prove quite difficult to do. There is evidence that the more active you are, the more carbohydrate you can allow without interfering with ketone production. The furthest ends of the keto spectrum are the “zero-carb” or “carnivore” lifestyle that allows only foods from the animal kingdom and the “vegan keto” lifestyle that excludes animal products entirely. In standard keto:
- Meat is typically encouraged, but since there are people out there who follow a vegan keto plan, animal products are certainly not required. Some keto advocates suggest limiting protein while others feel this is unnecessary. Standard keto advice is “low carb, moderate protein, high fat.”
- Dairy is allowed, but many would warn against any reduced fat dairy products as they tend to add sugar as a replacement. Hard cheeses are preferred and heavy cream is often encouraged as a replacement for milk.
- Generally all low carb veggies are fair game, and the more fibrous they are the better as this blunts the rapid glucose spike significantly. Many don’t even count fiber as a carbohydrate when counting their macronutrients. Some keto proponents even encourage dark chocolate at 80% cacao or above due to the high fiber content. Starches and grains are typically forbidden.
- Fruits are generally frowned upon in keto, but many allow berries and other lower carb fruits as long as they are in small quantities.
- Many people allow limited sweets as long as they fit their macronutrient allowance for the day or week. Some people even follow a Cyclic Ketogenic Diet, which allows one “cheat day” of high-carb eating per week while maintaining strict macros the rest of the time.
- Those who follow keto for health reasons beyond just weight loss are often more careful to focus on eating saturated fats, mostly from animal sources, as they believe that vegetable oils (or more specifically industrial seed oils like canola oil that are so often found in processed foods,) are as much or more of a contributor to the poor health of the masses as sugar.
Common questions and the controversy surrounding them:
- Isn’t there research showing that the ketogenic diet has terrible side effects? Yes, actually there is. Studies were done long ago on children with epilepsy who were being treated with a ketogenic diet, and these are often brought up in conversation. Low carb advocates are quick to argue against many of those studies being presented as valid evidence due to the diet they were fed not being representative of what the average keto dieter would actually eat, among other confounding factors.
- Ketoacidosis is a dangerous condition– aren’t elevated ketone levels inherently dangerous then? Part of the controversy surrounding the ketogenic diet is that often people can confuse or fail to differentiate between Nutritional Ketosis and Diabetic Ketoacidosis. While elevated ketones are present in both, there is a big difference between the two. In a healthy metabolism ketones elevate in the absence of glucose. In a diabetic metabolism, ketones can elevate because glucose uptake is impaired, even in the presence of high glucose in the bloodstream. This is a highly controversial concept simply because the dietary guidelines for diabetics are heavily disputed.
- Isn’t the keto diet heavy in meat, and wouldn’t that be inherently unhealthy? This is controversial because there are a lot of studies that associate meat with poor health outcomes. Low carb advocates tend to scoff at this, claiming that most of the studies showing poor associations with meat are epidemiological studies, which by nature can only show correlation rather than causation, and other potential correlations are not effectively ruled out. Often online you will find conflicting data regarding the health of animal products and study design is typically at the heart of the discussion.
- I hear “Keto-flu” can be awful and that electrolytes can be an issue with the ketogenic diet. This can be a problem with a low carb diet. Because water bonds to glucose, much of the weight initially lost when we restrict carbohydrate intake is water weight because without the glycogen stores we tend to retain less water. When we lose that water, we often lose electrolytes with it. Most sources that advocate a ketogenic diet make recommendations to help manage and adapt to this.
- But the brain requires glucose! Don’t we NEED carbohydrate? We do need glucose, but that doesn’t mean we need to eat carbohydrates to get it. Our biology allows for us to create glycogen from proteins and fats through a process called gluconeogenesis. The part that makes this controversial is that some believe this is inherently unhealthy and that relying on this much slower and arguably more taxing process for the glucose we need might not be adequate, especially for someone as physically active as a swimmer.
- Won’t my cholesterol go up if I go keto? This does often happen, and again this is a very controversial topic. Many low carb advocates have argued for years that we should not fear dietary cholesterol, and also should not fear elevated LDL (the “bad” cholesterol.) This has caused a large number of researchers to go back to pick through data from past studies and pursue new research to question the status quo. It has been accepted for decades that we should avoid saturated fats and keep our cholesterol levels low, but there is a lot of evidence lately questioning whether the context of a low carb diet might cause this recommendation to be reversed.
- Can keto really improve athletic performance? There are actually many studies showing performance impairment when restricting carbohydrate. Low carb advocates have long claimed that this doesn’t match up to anecdotes and that there is a reason for it. They argue that there is a required adaptation period before athletic benefit can be impacted positively and have demanded that studies that don’t allow for this shouldn’t be considered as legitimate evidence. More recent studies have shown more positive results for LCHF, especially in low intensity endurance activities, but mixed results for more intense exercise, which of course leads to more questions that demand more studies. Studies have recently shown that people can adapt to burning fat at higher intensities than previously believed, and there is evidence that LCHF is “glycogen sparing” which would benefit swimmers if proved true. While more research is being done recently there has been nothing definitive enough to cause a complete paradigm shift in athletics for endurance or sprint based racing. One controversial figure in the diet wars is Dr Tim Noakes, author of Lore of Running. He was one of the first researchers to bring the concept “carb-loading” for athletics to the mainstream and has since taken a lot of heat for his complete reversal of opinion on the subject.
No matter your take on whether keto is a good option for the general population, or more specifically for swimmers, we are sure this is a topic that will be discussed as more athletes and coaches seek every advantage they can gain in training. We here at SwimSwam look forward to seeing how it works out for Michael, and also hope that more research is done so that we can make the most informed decisions possible regarding optimal health and training. We welcome (civil) questions and discussion in the comment section below.