"Opinion is like a pendulum and obeys the same law. If it goes past the center of gravity on one side, it must go a like distance on the other; and it is only after a certain time that it finds the true point at which it can remain at rest." Arthur Schopenhauer.
I cannot think of a more appropriate quote to describe the reactionary nature of nutritional research, trends, and online discussions in recent decades; I've been guilty of it myself. Since 2016, I've followed a ketogenic diet. Initially, my appetite for new information on this metabolic state was insatiable, but I was surprised by the dearth of research and lack of awareness in academia. I received my Master of Science in Human Performance from the University of Florida in 2006, and in our nutrition discussions, the only mention of anything keto-related was ketoacidosis, a serious condition that typically only affects Type 1 Diabetics. Naturally, I needed to learn more. In the first month alone, I devoured 41 published papers and several books. As I learned more, my approach evolved. I've been on both sides of that pendulum and have gained insights on when carbs could be useful-whether that be a season or a specific event.
During initial phases of emerging science, researchers and thought leaders comb through findings and observations to figure out what is reproducible. However, we are past that point with ketogenic diets. In the last decade alone, there has been an explosion in research. In 2010, if you were to search for ketogenic research on PubMed, you would've found over 100 results-compare that with 2020 where the same search will yield close to 500 results. We now see research on ketogenic diets and athletic performance, building muscle, and a host of other interesting subjects.
In this article, I will take aim at an area where I hope the pendulum swings in the other direction-ketogenic diets in the performance realm. You see, a century ago, ketogenic diets were being used as a nutritional therapy to treat epilepsy, but widespread use plummeted after the discovery of epileptic medications providing relief from seizures in a percentage of patients, albeit accompanied by side effects. We now recognize several types of seizures that are resistant to medication, but treatable with this nutritional therapy. As chronic disease rates skyrocketed, ketogenic diets were shown to provide relief for many of them. Naturally, clinicians, researchers, and laypeople began experimenting with these diets as a nutritional therapy.
We've also learned that ketogenic diets provide a metabolic advantage with respect to fat burning. I've repeated the phrase, "carbs are noise" over the years because along with the quick dose of energy they provide, there's a corresponding rise in blood sugar and insulin. Notwithstanding the health issues that arise from chronically elevated insulin, these fluctuations in blood sugar can trigger cravings and feed cravings to eat foods lacking nutrient density. This cycle is perpetuated over time, leading to poor results for body composition, performance and overall health.
Conversely, whether you're a weekend warrior, professional athlete, or soccer mom (or a combination of these), the fewer carbohydrates you eat, the more of a metabolic advantage you may gain. In 2002, Dr. Jeff Volek hypothesized that at maintenance, ketogenic diets may lead to increased fat mobilization vs. a standard Western diet-and this may even hold true if you are in a caloric surplus. The reasons for this are not fully understood, but as Dr. Ryan Lowery and Dr. Jacob Wilson pointed out in 'The Ketogenic Bible', two potential reasons are gluconeogenesis and decreased feed efficiency. When you consume carbohydrates, fat mobilization decreases because the body prefers using exogenous energy sources before moving to its fat reserves, and there are tissues (such as the brain) that need glucose to function optimally. With ketogenic diets, we are able to create glucose. Through gluconeogenesis, our bodies create (genesis) new glucose (gluconeo) by using non-carbohydrate sources such as triglycerides and amino acids. This process is energy-intensive-in order to create 1 gram of glucose, we need roughly 10 grams of fat.
For this reason, fat mobilization increases as carbohydrates drop. There's also an increased intake of fat, so finding the right balance is where self-experimentation is key. Ketogenic diets decrease feed efficiency (how well we store fat based on the food we consume)-and that is a good thing. For example, someone with high feed efficiency may be very successful at storing fat with only 2,000 kcals a day, whereas someone with low feed efficiency could eat 4,000 kcals a day and store very little of that energy as fat. In a study published in November of 2018, Ludwig et al. found that for every 10% decrease in carbohydrate intake, the subjects saw a substantial increase in energy expenditure (52 kcals). After 12% (within 2%) weight loss on a run-in diet, participants were randomly assigned to one of three test diets, which were controlled for protein and energy-adjusted to maintain weight loss within 2 kg.
High Carb: 60% (n = 54) | Moderate Carb: 40% (n = 53) | Low Carb: 20% (n = 57) | |
Difference in energy expenditure | 0 kcals | 91 kcals | 209 kcals |
As carbohydrate intake dropped, energy expenditure increased. The differences were more profound among participants in the top third of pre-weight loss insulin secretion (meaning the higher insulin levels were at the beginning, the greater the difference in caloric expenditure after the intervention). The low carb group also had significantly lower levels of ghrelin, a hunger hormone. Carbohydrates have their place in the athlete's arsenal, but their role may be more limited than previously thought. The key for athletes is to find the best variation of keto to achieve a balance of body composition, peak performance and recovery, and overall health through self-experimentation.
After three to six months, you'll have likely reached some level of keto-adaptation, allowing you to experiment with strategic carbohydrate supplementation for training and events. If you aren't already, consider tracking calories and macros for several days to establish your baselines. Once you have your protein, carbs, and fats, you can manipulate carbs and fats, and observe what happens. For example, a 200-pound male eating 180 grams of protein, 20 grams of carbohydrate, and 200 grams of fat may decide to "carb-up" on his three hardest lifting days. To keep it isocaloric (keeping calories the same) he'd adjust his carbs from 20 to 145 grams while lowering fat from 200 to 145 grams. Ideally, most of these carbs would be eaten in the hours preceding and following training-20 grams pre-workout, 80 grams post-workout, and then 45 grams divided into 1-2 more meals. Lastly, I recommend testing blood glucose and blood ketones for objective data.
The best blood ketone meter for this is Ketocoach. Simply record fasted blood glucose and blood ketones for three days, then compare those to your fasted numbers after carb-up days. You can also take readings before your largest carbohydrate meal, then again at one hour and two hours postprandial (after eating) to ensure your blood glucose drops to baseline within two hours. Every experiment is valid and should give you relevant information, no matter what happens. Just remember that what works for others may not work for you-the key is to figure out what those differences are, rather than remaining stagnant or dogmatic.
About the Author
Danny is currently a coach for KetoCoach's FastCoach app. A native of Miami, Florida, Danny received his bachelor's degree in political science from Columbia University in 2004, where he played football and was a three-time Dean's List recipient. Danny earned his Master's of Science in Human Performance from the University of Florida, where he worked with the national championship men's basketball team along with the tennis and golf programs. Shortly after, Danny became the Strength & Conditioning Coordinator for Virginia Commonwealth University basketball.
