Introduction
With the release of several books outlining a role in mental health, therapeutic ketogenic diets have grown in popularity. Some people think they are the same as keto diets for weight loss or blood sugar control in type 2 diabetes. They are similar but very different.
A therapeutic ketogenic diet is used for ketogenic diet therapy (also called ketogenic metabolic therapy, a type of medical nutrition therapy). A doctor may prescribe it, or a dietitian may implement it under a doctor’s supervision as part of treatment for mental health and other conditions. [1]
There is no single “keto diet.” Most keto diets restrict carbohydrates and offer different levels of protein. They usually do not require weighing food or checking blood sugar or ketones, though some people choose to. Therapeutic ketogenic diets tightly control protein and carbohydrate amounts relative to fat. Diet plans such as 4:1, 3:1, or 2:1 require weighing ingredients and monitoring blood glucose and ketones. [1]
Therapeutic Ketogenic Diets
Therapeutic ketogenic diets have been used for more than 100 years in the treatment of epilepsy and diabetes, and more recently as adjunct treatment in some types of cancer and in mental health.
These diets are very high in fat, from 65–72% (2:1) up to 90% (4:1). [1] Protein, fat, and carbohydrate are strictly controlled, so ingredients are weighed. Blood glucose and ketone levels are monitored to reach the desired Glucose to Ketone Index (GKI). [1]
Three Types of Therapeutic Ketogenic Diets
Since a therapeutic ketogenic diet is like a prescription, each ingredient is weighed to achieve the correct ratio, just as medicine has a dosage. High-fat, low-protein diets such as 4:1 and 3:1 ketogenic diets make Meal Plan design both time-consuming and challenging. Meals in a therapeutic ketogenic diet are precise amounts of ingredients assembled to be as palatable as possible.
Classic Ketogenic Diet (KD) – 4 : 1
The 4:1 KD is used for epilepsy and seizure disorders, and is sometimes used along with chemo or radiation for cancers like glioblastoma. The classic Ketogenic Diet (KD) has a 4:1 ratio, i.e., 4 parts of fat for every 1 part protein and carbohydrate. That is, for every 5 grams of food, there are 4 grams of fat and 1 gram of protein, and/or carbohydrate. [1]
Modified Ketogenic Diet (MKD) – 3 : 1 ratio
The Modified Ketogenic Diet (MKD) has a 3:1 ratio, i.e., 3 parts fat for every 1 part protein and carbohydrate, with 75% of calories from fat, and 25% from a combination of protein and carbohydrate. Protein may be set at 15% of calories, with a maximum of 10% of calories coming from carbohydrate.
Modified Atkins Diet (MAD) – 2 : 1 ratio
The Modified Atkins Diet (MAD) has a 2:1 ratio, with 2 parts fat for every 1 part protein and carbohydrate. Fat is set at 60% of calories, protein at 30% of calories, and carbohydrate at 10% of calories.
The Popularized “Keto Diet”
There is no one “keto diet”, but rather a range of keto diets. They all limit carbs to about 10% of daily calories to encourage ketone production. The popular high-fat / moderate protein version of a keto diet with ~75% fat and 15% protein is commonly referred to as “the keto diet,” but this is not the only keto diet, nor the first.
The high-fat, moderate-protein version became popular in 2016 with the publication of Dr. Jason Fung’s books, The Obesity Code [2] and The Complete Guide to Fasting [3]. Unlike therapeutic diets, protein is not tightly regulated in the popularized keto diet. Food does not need to be weighed, and ketones do not need to be monitored. These diets are often used for weight loss or blood sugar control, but are not therapeutic diets.
A Well-Formulated Ketogenic Diet
In their book, The Art and Science of Low Carbohydrate Living [7], Dr. Stephen Phinney and Dr. Jeff Volek outline a “well-formulated ketogenic diet.” Since ketosis can occur within a fat intake range between 65-85% of calories, protein intake can range from 21-30%. Although this diet specifies the amount of protein, fat, and carbs for weight loss and maintenance, it is not classified as a therapeutic ketogenic diet.
It is my opinion, a well-formulated ketogenic diet containing 21–30% protein is preferable for older adults to the 15% protein provided by popularized keto diets, as the higher amount will help older adults retain muscle mass and avoid sarcopenia.
Final Thoughts…
Both therapeutic ketogenic diets and keto diets limit carbohydrates, but therapeutic diets also tightly control protein. Therapeutic ketogenic diets also require precise weighing and tracking of glucose and ketones, as these diets are dietary prescriptions. Meals high in bacon, eggs, and meat, common in popularized keto diets, are not part of therapeutic ketogenic diets.
More Info
While popularized keto diets offer benefits such as weight loss and improved blood sugar, they are not therapeutic diets. I design both therapeutic ketogenic diets and different types of keto diets and support people in implementing and transitioning between them based on individual goals.
Learn about me and the types of therapeutic ketogenic diets I design as adjunct therapy for physical and mental health conditions, which are implemented under a doctor’s oversight. View my Therapeutic Diet Services page.
To your good health,
Joy
You can follow me on:
Twitter: https://twitter.com/jyerdile
Facebook: https://www.facebook.com/BetterByDesignNutrition/
References
- Kossoff, E. H., Turner, Z., Cervenka, M. C., & Barron, B. J. (2020). Ketogenic Diet Therapies for Epilepsy and Other Conditions: Seventh Edition. Springer Publishing Company. [https://www.springerpub.com/ketogenic-diet-therapies-for-epilepsy-and-other-conditions-9780826149589.html]
- Fung, J. (2016). The Obesity Code: Unlocking the Secrets of Weight Loss. Greystone Books. [https://greystonebooks.com/products/the-obesity-code]
- Fung, J., & Moore, J. (2016). The Complete Guide to Fasting: Heal Your Body Through Intermittent, Alternate-Day, and Extended Fasting. Victory Belt Publishing. [https://www.victorybelt.com/product/the-complete-guide-to-fasting/]
- Eenfeldt, A. (2017). Low Carb, High Fat Food Revolution: Advice and Recipes to Improve Your Health and Reduce Your Weight. Skyhorse Publishing. [https://www.skyhorsepublishing.com/9781510710139/low-carb-high-fat-food-revolution/]
- Eades, M. R., & Eades, M. D. (1997). Protein Power: The High-Protein/Low-Carbohydrate Way to Lose Weight, Feel Fit, and Boost Your Health—in Just Weeks! Bantam Books. [https://www.penguinrandomhouse.com/books/44226/protein-power-by-michael-r-eades-md-and-mary-dan-eades-md/]
- Westman, E. C., Phinney, S. D., & Volek, J. S. (2010). The New Atkins for a New You: The Ultimate Diet for Shedding Weight and Feeling Great. Atria Books. [https://www.simonandschuster.com/books/The-New-Atkins-for-a-New-You/Eric-C-Westman/9781439190272]
- Volek, J. S., & Phinney, S. D. (2011). The Art and Science of Low Carbohydrate Living: An Expert Guide to Making the Life-Saving Benefits of Carbohydrate Restriction Sustainable and Enjoyable. Beyond Obesity LLC. [https://www.artandscienceoflowcarb.com/the-art-and-science-of-low-carbohydrate-living/]
© 2025 BetterByDesign Nutrition Ltd.
Joy Erdile is the Registered Dietitian at BetterByDesign Nutrition Ltd., and has been supporting clients’ nutritional needs since 2008. Joy has a post graduate degree in Human Nutirion, more than 17 years of experience in private practice, and is a published in mental health nutrition. She is licensed in BC, Alberta, and Ontario, and her areas of expertise range from routine to clinically complex cases. Joy is passionate about helping people feel better and restore their health, and believes that there is no one-size-fits-all approach, but that Nutrition is BetterByDesign©.