As of 2019, I doubt that there is anyone remotely interested in their health and fitness that has not heard of, or knows at least something about the “keto diet”. The keto diet is nothing new and is the most commonly used term for the low carb high fat diet diet that has gone by many names throughout the last century. It’s not my position to recommend anyone go on the keto diet or to avoid it but I want to offer some perspective. Simply put, a ketogenic diet is characterized by the the lack of significant dietary carbohydrates, >50g per day. Accompanied by a mild increase in proteins and significant increase in fat. After a few days of restricted carbs, glucose (carb/sugar) levels in the body become too low to provide energy for the brain and to low to break down fat for energy [yes carbs are typically required to breakdown fat (krebs cycle)]. When this happens the body’s adaptive nature causes it to seek other viable sources of fuel.Turns out the brain’s fuel sources aren’t just limited to sugar but can run on ketone bodies. So in simplest terms, you can survive without carbs, and if low carb diets are more efficient at creating and maintaining a lean physique than low fat diets wouldn’t a ketogenic diet be ideal for everybody? This is what some would have you to believe, and maybe a ketogenic diet would be beneficial, but it’s not the whole story. There are several points that are worth your consideration if you are contemplating the diet for yourself, or someone you coach so I thought I would share my personal experience with the diet.
I pride myself on my ability to adhere to a regimen in the gym and in the kitchen, and even I had some difficulty with this diet for three reasons. For one, the keto diet is not some casual attempt at cutting out carbs and replacing them with fatty foods. It’s an extremely high-risk high-reward diet. Its success is reliant upon you adhering to a very precise macronutrient intake tailored to your specific metabolic needs. It required some of the most dedicated meal prepping I’ve ever done because the diet allows such little room for error. Secondly, the process is unforgiving. You cannot simply take a day off from your keto diet and have some carbs (cheat days don’t work) because as soon as you reintroduce dietary carbs your body is pulled out of the process and it may take several days to restart. At the time when I was adhering to a keto diet, I was working a job 2 hours away. I found it incredibly challenging to adhere to the diet on the road not only practically, but without significantly annoying the hell out of my boss and coworkers. It was not impossible, but it was inconvenient enough for me. I remember one day in particular my boss’s choice of restaurant was the local Popeye’s. I hadn’t eaten since 6am and the clock was pushing 2pm. We’d spent the whole day moving heavy steel by hand, so needless to say my stomach was talking. I learned that day that Popeye’s doesn’t serve a single thing that isn’t breaded and deep-fried. It took me a week to get back on keto. Secondly, if you are an athlete for whom anaerobic performance is of any importance, you will likely notice a decrease in performance. Keto is unwise for weightlifters, sprinters, wrestlers, MMA, Bodybuilding and similar disciplines, at least in the long term. There have been several high profile athletes who touted the benefits of the diet for a period of time only to find themselves declining in performance after several months. The reason for this is partially due to dramatic elimination of liver and muscle glycogen (carb energy fuel tanks). This will become quickly apparent to the athlete within just a few days of the diet. In my personal experience with the keto diet, I actually felt pretty good for the first month. I noticed an increase in mental clarity, a decrease in body fat, and I actually had no significant decrease in athletic performance in the gym—until month 2 and 3. The long-term effects of the keto diet may lead to a decrease in muscle tissue due to depleted levels of growth hormone and mTOR activity (prevents muscle wasting by controlling cell growth in response to nutrient availability and growth factor signaling). This remains true even if you continue to implement resistance-training programs to promote hypertrophy (increased muscle size). I monitor my strength gains closely and I noticed my numbers begin to plateau, and then slowly decrease throughout the second and third month on keto.
So again, if you are considering keto, consider your goals first. Although I appreciated the fat loss, my priorities are more centered on long-term athletic performance and strength gains in the gym. For these reasons, among others, I chose to abandon the keto diet knowing that I can still successfully shed body fat through a more traditional, sustainable, and forgiving style of eating that also fuels my fitness goals. If you have a health complication such as a metabolic syndrome, cancer, epilepsy, or if your singular goal is fat loss, then do your research and consult your dietitian before trying it out. If you are a performance athlete, bodybuilder, or attempting to build your muscle size, you have much better options.