When Not To Be on a Ketogenic Diet

When Not To Be on a Ketogenic Diet


When Not To Be on a Ketogenic Diet

A ketogenic diet is a very low carbohydrate, moderate protein and high fat based nutrition plan.  A ketogenic diet trains the individual’s metabolism to run off of fatty acids or ketone bodies.  This is called fat adapted or keto adapted, when the body has adapted to run off of fatty acids/ketones at rest.

This nutrition plan has been shown to improve insulin sensitivity and reduce inflammation.  It also improves cellular healing and mitochondrial biogenesis which supports stronger and healthier cells.  All of this leads to reduced risk of chronic disease as well as improved muscle development and fat metabolism (12).


Where Ketosis Can Be Extremely Beneficial

There are certain cases, where I typically recommend a ketogenic diet as the research appears to support that ketosis significantly improves the functionality of these individuals.

Overweight or Obese

Neurodegenerative Conditions such as dementia, Alzheimer’s and Parkinson’s

Most Cancers but especially those of the brain, nervous system and blood (leukemia)

Chronic Pain

Seizure Disorders

Non-Elite athletes or individuals looking for higher mental & physical performance

The final one is the area that I and many others who have pursued a state of ketosis fall into.  At this point in my life, I have no chronic diseases, I feel great 99% of the time, but I am always looking to improve my productivity and performance.  I have found being in mild-ketosis to be one of the best ways to improve my energy, mental acuity, creativity, physical strength and overall life performance.


When Ketosis Shouldn’t Be the Desired State

There is no one diet that works perfectly for everyone.  Ketosis has the potential to benefit everyone, but under unique circumstances it would not be warranted.

Here are a list of special cases where long-term stable ketosis is not appropriate.  In some of these cases, short term mild-ketosis can be very beneficial but it is a case by case basis.

Pregnancy and Breast Feeding

Children and Teenagers

Irregular Menstrual Cycles

Adrenal Fatigue

Poor Thyroid Function

High Level Athletes


Insulin, Leptin and Female Hormones

Carbohydrates play a role in stimulating the release of insulin and insulin works with a hormone called leptin to help govern energy metabolism (3).   Leptin is released from fat cells as they enlarge during a meal and its main function is to signal to a part of our brain called the hypothalamus that we are satisfied and no longer need food.

Insulin is known to stimulate leptin synthesis.  A ketogenic diet significantly lowers insulin, which also lowers leptin levels (4).  Leptin receptors are found in the human ovaries and pre-ovulatory follicles.  Lower levels of circulating leptin can negatively affect the reproductive tissue and cause imbalances in key sex hormones in the female body (5).

Low leptin levels send a message to the body that it is in a time of famine, which can cause a stress response.  In these cases, reproductive functions are not prioritized (because the body doesn’t believe the environment is conducive to bringing about life).

This is especially true for women who are already lean and are sticking with a strict ketogenic diet.  Women, who naturally have higher body fat levels, will have slightly higher leptin levels while women who are very lean will naturally have lower leptin levels.

Science and research tells us that leptin is needed to maintain female hormone levels in their proper range (6).  These hormones are critical for menstruation, fertility, lactation and reproduction.  If we lose leptin sensitivity from a higher carb, inflammatory diet or if our leptin levels drop too low from prolonged ketosis, it can spell hormonal problems for women.


Pregnancy and Breast Feeding

As babies are developing the mother’s womb it is critical that the body doesn’t experience any sort of threat of food scarcity.   During this stage, it is not appropriate to practice lengthy periods of intermittent fasting or attempt to be on a ketogenic diet.

My wife is currently pregnant with twin boys as I am writing this and she consumes roughly 60-80 grams of carbohydrates on a typical basis.  So it is still a lower carb diet but not the 50 grams or less that is necessary to be in mild-ketosis.

The best sources of carbohydrates are those that are packed full of anti-oxidants.  I suggest extra berries, yams, sweet potatoes, pumpkin, carrots and beets.

Children and Teenagers

Children are growing and developing so rapidly and major bodily stressors can negatively effect this.  Being in a long-term state of ketosis was shown to help reduce seizures in teenagers with epilepsy but 45% of the girls reported menstrual irregularities such as amenorrhea (no menstrual cycle) and delayed puberty (7).

The only time I recommend a full-ketogenic diet is when children have either epilepsy or another seizure based disorder or if they have cancer.  Other than that, I encourage parents to give their kids some low-glycemic fruit in the form of berries, granny smith apples, kiwi, grapefruit, etc. as well as root vegetables such as sweet potatoes, pumpkin, carrots and beets.

Irregular Menstrual Cycles

If you are noticing irregular menstrual cycles on a ketogenic diet, than I would consider bumping up your carbs into that 60-80 range and see what happens.

This is especially important if you are doing a lot of high intensity exercise.  The combination of low-carb and high intensity exercise in a lean woman can be a set-up for disaster.  Doing this can put the body into a chronically stressed mode and wear out the adrenal glands causing poor exercise recovery and fatigue as well as premenstrual symptoms (8).


Adrenal Fatigue

The adrenal glands are designed to help the body adapt to stressors.  They allow us to think sharply, run and jump and make quick decisions.  To do this, they play an important role in regulating blood sugar levels in order to make sure we have the sugar in our system for quick and immediate energy.  Adrenal fatigue takes place when the body is under chronic stressors the adrenal glands can no longer keep up with the demands (9).

The common symptoms of adrenal fatigue include the following:

Low Energy                                        Lethargy & Fatigue

Rapid or Extra Slow Heart Rate      Increased Irritability

Sleep Disturbances                             Irregular Menstruation

Increased Muscle Soreness               Poor Exercise Recovery

Digestive Disturbances                      Depression

Inability to Gain or Lose Weight      Anxiety

Lean women who are under stress, do high intensity training and are on a ketogenic diet may be creating a state of chronic stress that there system is unable to adapt too.  Cycling out of ketosis, reducing your training load and improving rest along with using things like adaptogenic herbs and B vitamins can help you to recover effectively.

Most men can recover from adrenal fatigue much faster than women, because they have a different hormonal system that is easier to get under control.  However, if you are a man dealing with adrenal fatigue, it would be a good idea to cycle out of ketosis, get some good rest and using adaptogenic herbs to speed up recovery would be advised before going back into ketosis.


Poor Thyroid Function

The thyroid helps to regulate metabolism and energy levels throughout the body.  If you are in adrenal fatigue, it is a natural mechanism for the body to downregulate thyroid function.  One way the body does this is by increasing reverse T3 (rT3) which is an inactive form that competes with active T3 for cell receptor activity (10).

The body does this as an intelligent response because it is trying to conserve resources and put us in a state of hibernation so we can rest and recover effectively.  If the body allowed the thyroid to continue to function at a high level while we were already experiencing adrenal fatigue, it would drive us into a deeper stage of adrenal fatigue that could be life threatening.

It is important to note that many people with hypothyroidism do very well with a cyclic ketogenic diet, but if adrenal fatigue is the major mechanism, than it can be harmful.  Take time to support the adrenal glands and then try going back into ketosis.


High Level Athletes

If you are a high level athlete that is competing in Cross-Fit, triathlons, iron-man, long-distance runs, soccer, basketball and football than the ketogenic diet may be challenging.  When you are working your body at an extremely high level of activity, you need more calories and quick fuel that is immediately available in your muscle and liver.

A ketogenic diet for a high level athlete can be incredible but it is much tougher to follow and the risk of adrenal insult is higher than someone who is doing a smaller load of exercise.


Cyclic Ketosis and Carb-Back Loading

The best way to add back carbs is to boost them up in the evening.  The reason for this is that keeping your carbs low throughout the day is the best way to keep your blood sugar stable and prevent cravings.  Once you begin eating carbs during the day, you will notice a much greater degree of hunger throughout the day.

Additionally, we naturally have higher cortisol in the morning and cortisol helps to increase blood sugar.  At night, cortisol should naturally drop while melatonin rises so we can sleep well.  If our blood sugar is too low and we don’t have enough stored sugar (glycogen) in our muscles and liver than our body may perceive a time of famine and drive up stress hormones and blood sugar.

Taking in carbs in the evening helps to keep stress hormones down and also provides sugar to refuel the muscle and liver glycogen stores.  When the body has full glycogen stores, it is much less likely to perceive a time of famine.

Once your adrenals are reset, you only want to add back carbs on evenings where you did some sort of exercise.  The exercise will pull glycogen out of the muscles and liver and we want to replace that so the body doesn’t get worries about the lack of glycogen.  On rest days, go low-carb as your stored carbohydrate in your muscle and liver are still full, so your body won’t perceive this as a period of famine.


Dr Jockers Favorite Carbohydrate Sources

I personally will do 2-3 higher carb days (60-100 carbs max) each week on my higher training days.  What is really cool is that after fasting for 14-16 hours the next day,  I am typically back into mild-ketosis.  This process allows me to do very high intensity training while keeping my adrenals and thyroid healthy.

My favorite carb sources include the following:

  1. Berries: By far the best because they are loaded with anti-oxidants and powerful DNA protecting nutrients such as anthocyanins (blueberries and blackberries) and ellagic acid (strawberries and raspberries).
  2. Beets: Great prebiotic fiber and loaded with B vitamins.  The best food source of trimethylglycine (also called betaine) which is key for protecting our DNA.  If beets didn’t have sugar in them, I would suggest we all eat them everyday!
  3. Carrots: Great prebiotic fiber and beta carotene.  Carrots and beets are two of the very best foods for stimulating healthy peristaltic activity in the gut for good bowel movements.
  4. Sweet Potatoes: Great prebiotic fiber and loaded with beta carotene and tastes great.
  5. Pumpkin: Just like sweet potato, loaded with prebiotic fibers and beta carotene for a healthy body.
  6. Raw Honey: Raw honey has bee pollen and propolis within it that have profound immune system benefits.  It also has over 100 active enzymes, bioavailable amino acids and B vitamins.  If it didn’t have so much sugar, it would be one of my top health foods.
  7. Grade B Maple Syrup or Coconut Nectar: These are minimally processed sugars from the maple tree and the coconut tree.  These natural sugars also have lots of B vitamins and enzymes to support the bodies energy levels.
  8. Quinoa: This is not technically a grain, but instead it is a starchy seed.  Most people tolerate it well and it is loaded with complete protein, minerals and B vitamins.
  9. Unripe Bananas and Plantains: Green bananas and green plantains are unripe and there fibrous starch has yet to ripen into sugar.   This form of starch is called “resistant starch” because the human digestive system cannot form calories from it.  Meanwhile, our microbiome can break it down and use it as fuel.  These do still contain some level of sugar and digestible carbs so they will increase your blood sugar but not as much as fully ripened bananas and plantains.
  10. Brown or White Rice: I am not a big fan of rice, but for an occasional carb feeding it can be a good source.  While brown rice has significantly more nutrients than white rice, some people have problems with the lectins in the brown rice.  White rice is known to be a great prebiotic fiber and dosn’t have the lectin load that brown rice has.

These are all sources that are most often well-tolerated.  Grains and legumes are common food sensitivities that cause further adrenal stress on the body.  If you feel as though you tolerate beans well, than by all means use those.  If you have gas, bloating and inflammation when you consume them (or anything on this list) than I would recommend avoiding it.

Additionally, I would recommend using some of the blood sugar supportive elements in this article to reduce inflammatory spikes in blood sugar when you are carb loading.


Sources For This Article Include:

  1. Krilanovich NJ. Benefits of ketogenic diets. Am J Clin Nutr. 2007 Jan;85(1):238-9; author reply 239-40. PMID: 17209202
  2. Manninen AH. Metabolic Effects of the Very-Low-Carbohydrate Diets: Misunderstood “Villains” of Human Metabolism. Journal of the International Society of Sports Nutrition. 2004;1(2):7-11.
  3. Benoit SC, Clegg DJ, Seeley RJ, Woods SC. Insulin and leptin as adiposity signals. Recent Prog Horm Res. 2004;59:267-85. PMID: 14749506
  4. Park S, Kim da S, Kang S, Daily JW 3rd. A ketogenic diet impairs energy and glucose homeostasis by the attenuation of hypothalamic leptin signaling and hepatic insulin signaling in a rat model of non-obese type 2 diabetes. Exp Biol Med (Maywood). 2011 Feb;236(2):194-204. PMID: 21321316
  5. Karlsson C, Lindell K, Svensson E, Bergh C, Lind P, Billig H, Carlsson LM, Carlsson B. Expression of functional leptin receptors in the human ovary. J Clin Endocrinol Metab. 1997 Dec;82(12):4144-8. PMID: 9398729
  6. Elias CF, Purohit D. Leptin signaling and circuits in puberty and fertility. Cellular and Molecular Life Sciences. 2013;70(5):841-862.
  7. Mady MA, Kossoff EH, McGregor AL, Wheless JW, Pyzik PL, Freeman JM. The ketogenic diet: adolescents can do it, too. Epilepsia. 2003 Jun;44(6):847-51. PMID: 12790900
  8. Nazem TG, Ackerman KE. The Female Athlete Triad. Sports Health. 2012;4(4):302-311.
  9. Allen LV Jr. Adrenal fatigue. Int J Pharm Compd. 2013 Jan-Feb;17(1):39-44. PMID: 23627245
  10. Kahana L, Keidar S, Sheinfeld M, Palant A. Endogenous cortisol and thyroid hormone levels in patients with acute myocardial infarction. Clin Endocrinol (Oxf). 1983 Jul;19(1):131-9. PMID: 6684511
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14 Responses to When Not To Be on a Ketogenic Diet

  1. Keith Runyan, MD October 22, 2015 at 11:01 am #

    I realize your article is about when not to be on a ketogenic diet but since you listed conditions for which a ketogenic diet is beneficial, I felt your readers should know that a ketogenic diet is most thoroughly documented in published studies to be beneficial for the treatment of diabetes. Since type 2 diabetes is a state of insulin resistance and carbohydrate intolerance, a ketogenic diet can actually place type 2 diabetes in remission permanently. I avoid using the term cure because the propensity for insulin resistance does not go away necessarily and thus resuming a high carb diet will result in the return of elevated blood glucose in many cases. However, a ketogenic diet as a permanent lifestyle change can result in normalization of blood glucose, avoidance of the longterm complications, reduction or elimination of diabetic medications including insulin which for such a simple and cost effective therapy is amazing! The same can be said for type 1 diabetes. A ketogenic diet results in near normal blood glucose with reduction in insulin doses and hypoglycemic episodes. For those interested in learning how to implement a ketogenic diet for diabetes, visit http://www.ketogenic-diet-resource.com. Best wishes for excellent health, Keith Runyan, MD.

    • Dr. Jockers October 22, 2015 at 11:06 am #

      Yes, very good info Dr Keith! Thanks for sharing that!

  2. Eileen February 3, 2016 at 2:58 pm #

    This is an excellent article, I am very grateful for the specifics here, such as the food list of better carbs to eat later in the day. Very helpful for me personally, confirms some of my own thoughts, and advice from my healthcare practitioners.

    There is very little balanced information out there on this topic. Mostly extreme pro or anti keto voices, as if one size fits all. Thanks so much!

    • Dr. Jockers February 3, 2016 at 3:40 pm #

      Thank you so much for the wonderful feedback Eileen!

  3. Karen February 4, 2016 at 6:13 am #

    Great information! I have no natural thyroid function due to radioactive iodine treatment of Graves Disease 25+years ago. My thyroid hormones are supplied by Nature-Throid (T4+T3). I’ve been successful at losing weight, though slowly, by sticking to a ketogenic diet for the past 3 months and I feel good. Would I fall into the category of poor thyroid function individuals who shouldn’t be following a ketogenic diet? Thank you.

    • Dr. Jockers February 4, 2016 at 7:28 am #

      Thanks Karen! The poor thyroid function is actually more of an adrenal fatigue related issue. If you are feeling well and losing weight doing the ketogenic diet, than I would stay on it, if you begin to feel like you have low energy, dry skin, etc. than try cycling in and out of ketosis. Blessings!

  4. Thao Nguyen March 8, 2016 at 11:29 am #

    Dear Dr. Jockers,

    I’m a regular susbsriber of your blog and I’d like to say thank you for sharing your knowledge and wisdom!

    God bless your family and your work!

    • Dr. Jockers March 8, 2016 at 11:53 am #

      Thank you so much Thao! That means a lot!!! Blessings to you and your family too!

  5. Elman March 8, 2016 at 12:14 pm #

    You said that a ketogenic diet is not good for elite athletes. Yet that is one area it is often specifically used for. Then, you listed what you meant. Generally ketosis produces slower reaction times and slower sprinting such as needed by football and soccer players. Thus it would probably be detrimental to their performance. Where it does well is with endurance athletics, for continued exertion for periods of time significantly longer than someones glycogen stores can last, which for runners is often about twenty miles. That is it could be useful for marathon runners, Iron man competitors, ultra marathon runners, ultracycling and any many hour continuous exercise event.

    • Dr. Jockers March 8, 2016 at 12:23 pm #

      Yes it can be used for athletes and many have reported great results. I recommend a cyclic ketogenic diet for athletes

  6. Grace September 30, 2016 at 9:17 am #

    Dr Jockers I had my gallbladder removes about 7 years ago. I have some issues when eating fatty meals sometimes. Is this diet ok for someone with no gallbladder? and I also have high blood pressure and take meds for that.


  7. AJ April 4, 2017 at 12:02 pm #

    Dr. Jockers,
    Your article answered most of the questions I’ve been wondering about Ketosis. My husband is on a Ketosis diet and he’s been taking it very seriously. Unfortunately, for me that means I’m on it too since we can’t afford, nor have the time, to have two different meal plans. For me, ketosis didn’t seem to have the same effect as my husband. I’m 5’2 hovering just above 100 pounds, but also Asian (which means I’m more vulnerable to diabetic conditions, even though I’m within normal bmi standards). Since being on Ketosis, I’ve been irregular and tired. I’m not sure it’s because of the diet or maybe I need to power through it? My second question is, for someone like me would ketosis most likely reduce or increase my leptin sensitivity?

    • Dr. Jockers April 5, 2017 at 10:29 am #

      Hey AJ,

      A ketogenic diet should improve your leptin sensitivity. I would recommend using a lot of fiber in the form of avocados and chia seeds and drinking extra water with minerals and magnesium in order to get your bowels and energy going again. When you are on a low-carb diet, you excrete more sodium and electrolytes so you need to replace them. You can make a lemonade with lemon juice, water, a pinch of sea salt (best is Himalayan pink salt), and stevia to taste. You can also do organic, free range chicken broth and drink that throughout the day to add electrolytes.

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