By Julie Cornelius, MS


I have been asked numerous times recently what my opinion is about the so-called “Ketogenic Diet,” which is basically a very low carbohydrate diet. In the past year or so, this diet has been recommended to athletes as a way to “improve fat burning” and “help teach your body to not rely on carbohydrates.” There are better carbohydrate sources than others. Aim for getting the majority of your carbohydrates from fruits, vegetables, root vegetables such as potatoes, and some whole grains like brown rice and oats. These sources will contain more nutrients and tend to be lower on the glycemic index- meaning you will have a steadier source of carbohydrates that can help prevent huge sugar spikes, and huge energy crashes.

Below, I want to give you the reasons why this diet is not recommended for anyone including athletes- and frankly can be dangerous!


  1. Not eating carbohydrates leads to ketones- ketones are acidic and can lead to organ damage

So yes, its true- when you don’t consume carbohydrates, your body will break down fat for energy. The problem is, when you deplete all of your glycogen (how your body stores carbohydrates), your body will begin to produce what are called ketones. Basically, your brain functions on carbohydrates, but since your brain is such an important organ, your body has a built in survival method for the absence of carbohydrates. That is, it will start to break down fat and produce ketones. Your brain can use these ketones as fuel when carbohydrates are not around. The problem is, those ketones will cause your blood to be on the acidic side. There is a lot of research that shows that a more alkaline diet (opposite of acidic) may prevent muscle wasting, reduce the risk of high blood pressure and stroke, improve cardiovascular function, improve memory and cognition, and possibly prevent bone loss.

  1. A low carbohydrate diet lacks fiber.

Fiber has a lot of health benefits, including improved digestive health, lower cholesterol and weight loss/management. Fiber can also help to stabilize blood sugar- important for preventing huge energy crashes, Type II Diabetes and excess weight gain. Fiber is also food for beneficial bacteria (yes there are good ones!) that live in your gut. These bacteria help make up your immune system and even produce vitamin K. Eat healthier carbohydrate like fruits, vegetables, and whole grains to get fiber in your diet.

  1. A low carbohydrate diet lacks antioxidants and phytonutrients.

Every day, we are bombarded with various chemicals in our environment that can do damage to our cells. Every time you do exercise, there is oxidative damage that occurs. Basically, throughout the day, free radicals are produced through these chemicals, as well as during exercise and they can do damage within our body. A diet that includes fresh foods, including fruits and vegetables ensures that you are getting enough antioxidants, which help to neutralize these free radicals and prevent them from doing damage.


  1. You need glycogen stores for endurance activities.

Your body stores carbohydrates in the form of glycogen. During any activity, your body draws on these glycogen stores for energy. Your glycogen stores are much more limited than fat stores- you only have about 1500-2500 calories stored as carbohydrates on average. For endurance athletes, these carbohydrates are crucial. When your glycogen is depleted, it leads to bonking, also known as “hitting the wall.” Making sure to get enough carbohydrates (and the right ones!) can help to improve your athletic performance and keep you going longer.


Julie CornelIMG_1601ius, MS is Co-founder of Potential Energy Training & Nutrition. She has an extensive background in nutrition and graduated from the University of Arizona in Tucson, AZ with both her Bachelors of Science and Masters of Science in Nutrition.  She has worked in fitness studios helping clients achieve their nutrition goals, spent two years teaching college nutrition courses, and was the founder of Julie Bar, an energy bar company. Julie is a long time cyclist and mountain biker who loves being outdoors. Julie helps individuals to meet their nutrition goals, whether it is eating to win an endurance mountain bike race, losing weight, or just eating to be healthier. Connect with Julie:

4 Reasons Why You Should NOT Try the Ketogenic (Low Carbohydate) Diet