What is the Ketogenic Diet? (+Foods, Benefits, Risks)

Ketogenic Diet: Should You Join the Keto Kraze?

In this article you will learn:

What is the Ketogenic Diet?

The ketogenic diet has been used clinically for over 80 years, primarily for the symptomatic treatment of epilepsy in children.  The classic ketogenic diet was developed in the 1920s to mimic the biochemical changes associated with periods of limited food availability.

The diet is composed of approximately 75% fat, 5% carbohydrate and 20% protein, and while it provides adequate protein for growth, it provides inadequate amounts of carbohydrates for the body’s metabolic needs. Energy is primarily derived from the utilization of fats, which are converted to the ketone bodies β-hydroxybutyrate, acetoacetate, and acetone. These ketone bodies serve as an alternative energy source to glucose. In comparison to glucose, ketone bodies have a higher inherent energy.(1)

Keto Foods

The majority of meals in a ketogenic diet consist of these foods:

  • Meat: Red meat, ham, sausage, bacon, chicken and turkey.
  • Fatty fish: Salmon, trout, tuna, sardines, anchovies and mackerel.
  • Eggs: Ideally pastured or omega-3 whole eggs.
  • Butter and cream: Grass-fed is preferable.
  • Cheese: Unprocessed cheddar, goat, cream, blue or mozzarella.
  • Nuts and seeds: Almonds, walnuts, flax seeds, pumpkin seeds, chia seeds, etc.
  • Healthy oils: Primarily extra virgin olive oil, coconut oil and avocado oil.
  • Avocados
  • Low-carb veggies: Most green veggies, tomatoes, onions, peppers, etc.
  • Condiments: Salt, pepper and various healthy herbs and spices.

Sample Meal Plan

  • Breakfast: Bacon, eggs and tomatoes
  • Lunch: Chicken salad with olive oil and feta cheese on greens
  • Dinner: Salmon with asparagus cooked in butter
  • Snacks: Nuts, avocado, peanut butter milkshake

Health Benefits

Several studies have shown the benefits of a ketogenic diet for patients with type two diabetes, such as weight loss, reducing blood sugar, reversing kidney disease, cardiac benefits, improvement in lipid profiles and even the potential effect on reversing diabetic neuropathy (nerve damage) and retinopathy (eye damage). (2)

Several neurological diseases (e.g.  epilepsy, headache, neurotrauma, Alzheimer’s disease, Parkinson’s disease, sleep disorders, brain cancer, autism, pain, and multiple sclerosis) are thought to be linked to energy dysregulation and as such, could be favorably influenced through dietary means.  

Despite the relative lack of clinical data, there is emerging literature supporting the use of the ketogenic diet for a variety of neurological conditions. These preliminary studies are largely based on the fundamental idea that metabolically, the ketogenic diet may have protective effects on the nervous system. (3)

Health Risks and Side-Effects

There are several concerns with following a ketogenic diet for long periods:


Many of the richest sources of fiber (e.g. beans, fruits and whole grains) are restricted on the ketogenic diet. Consequently, ketogenic eaters miss out on the benefits of fiber-rich foods such as regular bowel habits and microbiome support (A healthy gut flora).

Micronutrient deficiencies

Any diet that prohibits you from eating a variety of fruits, vegetables and other foods can leave you vulnerable to vitamin and mineral deficiencies.

Muscle loss

Some research suggests that the keto diet can lead to the loss of lean body mass.


It is believed that a ketogenic diet is inadequate in fiber, minerals, vitamins and phytochemicals, thereby increasing risk factors affecting mortality. Because ketogenic diets tend to result in a reduced intake of fiber and fruits, and an increased intake of protein from animal sources (along with cholesterol and saturated fat), the risk for mortality due to cardiovascular disease could potentially increase. Ketogenic diets may also be linked to an array of other chronic health problems. A positive cancer risk has been linked to the intake of animal protein and red and processed meat consumption, both of which are prevalent in the ketogenic diet.

Given the fact that long-term adherence to ketogenic diets are potentially unsafe and that calorie restriction has been demonstrated to be effective in weight loss regardless of nutritional composition, it would be prudent not to recommend low-carbohydrate diets for the time being.(4)

Effects on Sports Performance

According to Burke, there are several disadvantages to ketogenic diets for sports performance:

●     Ketogenic diets are glycogen impairing vs glycogen sparing, i.e. They adversely affect one’s ability to use carbohydrates for energy.

●     Ketogenic diets impairs both high-intensity work output (e.g. sprinting) as well as low intensity endurance performance.

●     Ketogenic diets reduce exercise economy by increasing oxygen demand.

Ultimately, macronutrients (carbohydrate, fat and protein) should be periodized to facilitate metabolic flexibility so that nutrients can be used preferentially based on activity.(5)

Keto and Weight Loss

According to the ISSN position stand on diets and body composition, diets primarily focused on fat loss are driven by a sustained caloric deficit. The higher the baseline body fat level, the more aggressively the caloric deficit should be imposed, in conjunction with increased protein consumption to maintain lean body mass. Slower rates of weight loss can better preserve lean mass in leaner subjects. The majority of controlled interventions to date that matched protein and energy intake between ketogenic diets and non-ketogenic diet conditions have failed to show a fat loss advantage of the ketogenic diet. Any advantage of a ketogenic diet vs a non-ketogenic diet for fat loss is potentially in the realm of appetite regulation. (6)

Ketone Ester Supplementation

Some studies support the use of supplemental ketones to provide extra fuel and preserve carbohydrates during prolonged exercise, thereby enhancing endurance performance. Exogenous ketones (500 mg/kg) to achieve active ketosis, along with a carb-smart diet, where carbohydrates are optimally consumed for performance, can enhance performance through a combination of fuel sparing and improved energetic efficiency. The performance enhancements are seen in endurance events (e.g. a marathon), but not glycolytic-based sports (e.g. sprinting). It should also be noted that achieving ketosis via dietary means does not confer the same performance benefits and will likely be ergolytic (performance impairing). (7)

Should You Do Keto?

A ketogenic diet could be an interesting short-term alternative to help manage certain health conditions and may be an option for weight loss. However, it can be difficult to sustain and is generally heavy on red meat and sometimes includes a lot of processed and salty foods that are unhealthy (e.g. bacon). In addition, at this point we still do not know enough about the long-term health effects.

Ultimately, instead of engaging in a ketogenic diet, a balanced, unprocessed diet, rich in colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and adequate water, seems to have the best evidence for a long, healthy, vibrant life. Carbohydrate periodization is a better approach as it is congruent with one’s energy needs and supports healthy weight as well as optimum sports performance (8)


  1. Ketogenic diets are composed of about 75% fat, 5% carbohydrate and 20% protein.
  2. Ketogenic diets can be used therapeutically for seizures, weight loss, type 2 diabetes and possibly neurodegenerative disorders.
  3. Ketogenic diets can adversely affect metabolic flexibility and impair carbohydrate metabolism.
  4. Ketogenic diets can adversely affect athletic performance, especially in sports relying on glycolytic (carbohydrate predominant) pathways for energy.
  5. Carbohydrate periodization is a better approach as it is congruent with an individual’s energy needs and supports healthy weight as well as optimum sports performance.
  6. Ketone ester supplementation can be used to provide extra fuel and to preserve carbohydrates during prolonged exercise, thereby enhancing endurance performance.
  7. In general, one’s diet should be balanced, unprocessed, rich in colorful fruits and vegetables, lean meats, fish, whole grains, nuts, seeds, olive oil, and adequate water.

Want to learn more about the Keto diet and nutrition in general? Become a Certified Nutrition Coach.

For any fitness professional – or anyone in general – looking to venture into the world of nutrition coaching, look no further than NASM Nutrition Certification. It’s your recipe for success.

Become an NASM Certified Nutrition Coach today.


Aragon, A. A., Schoenfeld, B. J., Wildman, R., Kleiner, S., VanDusseldorp, T., Taylor, L., … & Stout, J. R. (2017). International society of sports nutrition position stand: diets and body composition. Journal of the International Society of Sports Nutrition, 14(1), 16.

Azar, S. T., Beydoun, H. M., & Albadri, M. R. (2016). Benefits of ketogenic diet for management of type two diabetes: a review. J Obes Eat Disord, 2(02).

Burke, L. M. (2015). Re-examining high-fat diets for sports performance: did we call the ‘nail in the coffin’too soon?. Sports Medicine, 45(1), 33-49.

Cox, P. J., Kirk, T., Ashmore, T., Willerton, K., Evans, R., Smith, A., … & King, M. T. (2016). Nutritional ketosis alters fuel preference and thereby endurance performance in athletes. Cell metabolism, 24(2), 256-268.

Dashti, H. M., Mathew, T. C., Hussein, T., Asfar, S. K., Behbahani, A., Khoursheed, M. A., … & Al-Zaid, N. S. (2004). Long-term effects of a ketogenic diet in obese patients. Experimental & Clinical Cardiology, 9(3), 200.

Egan, B., & D’Agostino, D. P. (2016). Fueling performance: ketones enter the mix. Cell metabolism, 24(3), 373-375.

Gasior, M., Rogawski, M. A., & Hartman, A. L. (2006). Neuroprotective and disease-modifying effects of the ketogenic diet. Behavioural pharmacology, 17(5-6), 431–439.

Noto, H., Goto, A., Tsujimoto, T., & Noda, M. (2013). Low-carbohydrate diets and all-cause mortality: a systematic review and meta-analysis of observational studies. PloS one, 8(1), e55030.

Potgieter, S. (2013). Sport nutrition: A review of the latest guidelines for exercise and sport nutrition from the American College of Sport Nutrition, the International Olympic Committee and the International Society for Sports Nutrition. South African journal of clinical nutrition, 26(1), 6-16.

Rho, J. M., & Stafstrom, C. E. (2012). The ketogenic diet as a treatment paradigm for diverse neurological disorders. Frontiers in pharmacology, 3, 59.

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The Author

Geoff Lecovin

Geoff Lecovin

Dr. Lecovin is a chiropractor, naturopathic physician and acupuncturist, in addition he earned a Master's degrees in Nutrition and Exercise Science. He holds additional certifications in exercise from the National Strength and Conditioning Association (CSCS), International Society of Sports Nutrition (CISSN) and National Academy of Sports Medicine (CPT CES PES FNS WLS), where he is also an Master instructor.

Dr. Lecovin specializes in treating musculoskeletal pain and sports injuries by integrating trigger point acupuncture, soft tissue release, joint manipulation, corrective exercise and nutrition. In addition, he combines exercise and nutrition for weight loss, weight gain, performance enhancement and wellness. His clinic is located in Redmond, Washington. He can be reached at Northwest Integrative Medicine at (425) 999-4484 or at his website address:

Advice: Learn the fundamentals of exercise and diet from evidence based organizations such as the NASM and take continuing education classes or pursue higher education in order to keep up with the research. Becoming certified by the NASM has changed the way I practice and look at exercise.


  1. June 29, 2019 at 6:21 am — Reply

    This is an informative post. Got a lot of info and details from here. Thank you for sharing this and looking forward to reading more of your post.

    Women’s Health And Fitness

  2. Steven
    July 8, 2019 at 6:49 pm — Reply

    A caveat that can be added here is that it is an erroneous assumption that ketogenic diets be based upon animal proteins. While not the norm, there are people taking a plant-based approach and study on the so-called “Eco-Atkins” diet has shown benefits. There are also high fiber ketogenic foods available like chia seeds and avocados. I know someone who eats a high fat diet just shy of fully ketogenic who actually had to take steps to reduce their fiber intake. That said, it is a diet focused on health benefits, not performance.

  3. Daniel murphy
    July 12, 2019 at 4:55 pm — Reply

    I agree that ketosis may lower total output in the realm of anaerobic performance. However, when compared to aerobic and long term sustained endurance activities many claim to only have an increase in available stamina. What do you think about the Navy seals considering a ketogenic type diet? In some cases they have noticed an increase in the ability of their seals to hold their breath for longer periods under water while operating in ketosis.

  4. August 19, 2019 at 12:16 am — Reply

    I’m curious as to why lean meats are emphasized over red meat in this article as health promoting? As a nutritional therapy practitioner, I find lean and fattier cuts of meat (from high quality sources) can be very nutritious and part of a healthy diet.

    Great post! Thanks for sharing.

  5. August 29, 2019 at 9:51 am — Reply

    Thank you for sharing such a great informative information it’s very helpful and useful for me.

    Fitness Diet

  6. November 13, 2019 at 1:31 pm — Reply

    It’s interesting to know that it has been proven that supplemental ketones will provide extra fuel and preserve carbohydrates during exercise. My sister got recommendations on the keto diet, and we are looking for advice. I will let her read your article to help her understand more about the keto diet.

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