The Keto Craze: A Dietary Approach For Optimal Performance?

Landon Opunui

The Ketogenic Diet has become a trendy term. Many individuals are experimenting with a ketogenic diet for various health reasons. Implementing this diet correctly is important to minimize the risk of side effects and to maximize the health benefits. What is it exactly? What are the health benefits? What are the risks? Is it for everyone? 

The Old Sports Nutrition Paradigm: 

Sports nutrition has traditionally thought that we need carbohydrates broken down into glucose to fuel the body for function and performance. Carbo loading and sports drinks are two phenomenon most athletes have grown up with and continue to perpetuate today. When using carbohydrates as the primary fuel source, too much or not enough carbohydrates can be a difficult balance to find for endurance athletes. Too much sugar can cause digestive cramping, not enough can result in bonking or fatigue. The vicious cycle of the highs and lows of sugar and insulin levels can result in mood and cognitive impairment, sleep disturbances and poor recovery time. 

We all know that sugar should intuitively be taken out of the diet of patients with diabetes, but why shouldn’t we not explore this strategy in all stages of health and performance. In the absence of carbohydrates, fat oxidation increases to the point where ketones can be the primary fuel source. When keto-adapted body fat is being burned all day. Carbohydrate dependency metabolism is shifted to fat which is a much more reliable source of fuel.  

Nutritional ketosis allows for glycogen stores to be used more efficiently during higher bouts of intensity. In other words, we have the metabolic flexibility to shift back and forth between fat and stored sugar as fuel. Nutritional ketosis can overcome carbohydrate dependent sports nutrition. 

What is Nutritional Ketosis:

Ketosis is an energy state when food is scarce or carbohydrates are restricted that results in the bodies break down of stored fat to be converted into a fuel source called ketones. Nutritional ketosis is a dietary approach by which macronutrient ratios are manipulated in such a way that allows the body to become metabolically flexible.  In other words, an individual is able to use both glucose in the form of stored glycogen and fat as fuel.  Insulin levels are stabilized when on a high fat, low carb diet which may prevent the development and progression of many chronic diseases. Nutritional ketosis is accelerating the production of ketones by breaking down fat by restricting carbohydrates to achieve a blood ketone level between 0.5-3.0 mmol/L. Keto-adaptation means that you can efficiently use fat as fuel. 

What is the Ketogenic Diet:

The ketogenic diet consists of a macronutrient ratio of 70% fat, 20% protein, and 10% carbohydrates. In a 2,000 calorie diet, 10% carbohydrates will be 50g or less. This is very difficult to achieve with grains, starches, fruit, sugary beverages, alcohol and any processed foods with added sugar or flours in the diet. Fat is the staple of the diet and the source is really important. Fats should be primarily anti-inflammatory fats which as a general rule are the plant and fish sources. Fried foods and refined/processed fats should be avoided as in all diets. Butter, ghee, eggs, coconut oil, avocado, olives, macadamia nuts and non-predatory fish and seafood should be staples of the diet. Protein should be lean and moderately consumed as excess dietary protein gets converted into glucose in the liver. A well balanced ketogenic diet will be primarily a plant based diet with lean protein and healthy fats. A healthy ketogenic diet is very different from the Atkins diet that many think of when they hear high fat diets.   

What are the advantages of a Ketogenic Diet:

Not just for sports performance, there are many health benefits associated with the safe and effective implementation of a ketogenic diet. 

  • Stabilized and sustained high energy 
  • Increased fat loss
  • Improved digestion 
  • improved immunity from post-exertion induced immune suppression
  • Improved power to weight ratio because of decreased body fat
  • Improved insulin sensitivity (reduced diabetes risk)
  • Lower inflammation
  • Improved recovery time
  • Curb cravings
  • Slows down the aging process
  • Improved focus, concentration and cognitive performance 

How to implement the Ketogenic Diet: 

Increase dietary fats, consume reasonable amounts of protein while limiting carbohydrates to non-starchy vegetables. 

Generally, a ketogenic plate or meal should consist of the following:  

  • 1 fist of Protein (4 calories per gram)
  • 1 fist of Fat (9 calories per gram)  
  • The rest of the plate should be leaves and colored vegetables 
  • No grains, no starches, no fruit and no sugar
  • *½ -1 serving of low glycemic index fruit such as berries should still allow for nutritional ketosis 

Ketosis Side Effects: 

Insulin retains water and can make us bloated. With the water, also goes the electrolytes, so it is really important for those on a ketogenic diet to make sure that electrolytes are still balanced. A 2% water loss due to dehydration has been shown to reduce sports performance by up to 50%. Because of this dietary induced water loss, those on the ketogenic diet need to ensure adequate hydration. Symptoms of fatigue, headaches, flu-like symptoms and reduced sports performance can occur when dehydration and electrolyte deficiencies occur. 

A ketogenic diet is very different than the Standard American Diet (SAD). It takes 7-10 days for keto-adaptation to occur. During this transition, it is not uncommon for there to be a drop in sports performance. For athletes, it is important to move strategically when first exploring the ketogenic diet. Backing off on exercise intensity is important during the keto-adaptation phase. Focus on mobility, flexibility and hiking for exercise. This is not the time to do high intensity exercise. Once properly adapted, high performing exercise or competition can resume. 

There is no one-size-fits-all approach to diet. Not everyone can tolerate and thrive on this rather restrictive dietary approach. Certain genetic predispositions make individuals hyper-producers or hyper-absorbers of cholesterol. A high fat diet may be contraindicated in these populations. As always, it is important to consult with your physician before making any dietary changes that may affect your health.