Is A Ketogenic Diet Healthy (Part 3: The Risks)

Alright ladies and gentlemen this is the last installment in this series on the ketogenic diet. If you haven’t read the first two parts of this series you can find Part 1 HERE and Part 2 HERE.

As a quick refresher the ketogenic diet or nutritional ketosis is when someone eats very low carb, moderate protein and high fat.

Eating in this way shifts the body from metabolizing glucose from carbohydrates to using fats as a source of fuel. Most tissues in the body can use fat as fuel but the brain and nervous system can’t.

With increased  fat metabolism in the absence of carbohydrates a byproduct is produced named ketones. Ketones are a source of energy that can be utilized by both the brain and nervous system. When enough of these ketones are present in the bloodstream this is known as the state of ketosis.

Without the metabolic machinery of ketosis survival in times of food scarcity wouldn’t have been possible for our ancestors because without food we quickly deplete glucose to fuel the brain and nervous system. 

While the ketogenic diet has resurfaced and gained a lot of popularity recently with the explosion of paleo and low carb diets it is by no means a new diet.

It was first discovered in the 1920’s a treatment for children with epilepsy, and has been used for traumatic brain injury, certain forms of cancer, was even used by bodybuilders to help with fat loss.

Some of the benefits of following a ketogenic diet include appetite control and its effectiveness as a fat loss diet, lowering inflammation and helping with diabetes. Lastly there are some promising uses for the ketogenic diet in neurodegenerative diseases.

Today however in part 3 of our series  we are will be discussing the drawbacks and risks of  a ketogenic diet when it comes to its long term use. 

You will have to decide whether a ketogenic diet could benefit you personally. This blog series isn’t meant to encourage or discourage the diet, just to give you some context to consider.

Not everyone will experience these drawbacks of being on a ketogenic diet, some people who I know that eat a ketogenic diet have had any of the problems discussed below.  

Drawbacks of A Ketogenic Diet

Thyroid Health

In times of food scarcity or limited carbohydrate consumption the body will reduce thyroid hormones.  Reduced thyroid function is used as  a means to decrease the metabolic rate, and keep you alive longer.

In times of famine you would be able to stay alive much longer burning fewer calories, and with a lower metabolic rate.

With high levels of the stress hormones cortisol and adrenaline due to a lack of carbohydrates and glucose, the conversion of inactive thyroid hormone T4 to T3 can be  diminished.

Less T4 to T3 conversion impairs thyroid function and impacts digestion, metabolism, energy and the sex hormones testosterone and estrogen.  

Disrupted sleep

If someone already has a stressful lifestyle or reduced adrenal function, eating  a ketogenic diet can be an extra stressor that disrupts sleep.

The body can only handle so much stress before it starts to make adaptations that accommodate this highly stressed state.

We release the stress hormone cortisol in a highly predictable patterns throughout the day, but with too much stress you can flip the cortisol rhythm.

This flipped cortisol rhythm means you would have high cortisol at night keeping you awake (not good) and low cortisol in the morning making you tired (not good either).

A while ago I  was working with a client on a fat loss plan and we were slowly reducing his carb intake over the course of 4-6 weeks to ease him into cyclical ketogenic diet.  

Knowing that he had a high stress job and lifestyle I wanted to drop his carbs slowly over the course of 4-6 weeks to not over stress the body.

The next time we had a consult he explained that he went ahead and dropped the carbs down to much lower than we agreed and instead of eating 75-100 grams of carbs he  had been eating well below 50 grams per day for the last 2 weeks… not good.

He then began talking about how for the past week he had been waking up at 2:45AM like someone shot him out of a cannon wide awake and not able to fall back  asleep. This is exactly what I wanted to avoid!

Dropping his carbs too quickly on top of the other stresses he had in his life caused his cortisol pattern to flip and peak too early in the morning causing him to wake up and not be able to get back to sleep. We got his sleep back to normal using the Stanford Sleep protocol.

High Stress Hormones

Caloric and nutrient restriction is a stress on the body, as we spoke about in part two of this series part of the reason that a ketogenic diet can help with fat loss is the unintentional appetite suppression.

Short term that can be a benefit for fat loss, however long term caloric and nutrient restriction can come back to harm your health.

The body will call upon the stress hormones adrenaline and cortisol to mobilize energy in this stressed state, which if used in an emergency state infrequently is a good thing.

However if someone is relying on these stress hormones all day because they have restricted carbohydrates or calories for too long  it will slow down the metabolic rate, hinder digestive function, steal hormonal precursors, and decrease nutrient absorption.

Not to mention the body will become less responsive to the stress hormones can set the stage for adrenaline resistance making it more difficult to mobilize body fat.

Digestive Problems

An overabundance of the stress hormones inhibits digestive function beginning with insufficient production of hydrochloric acid (HCL) in the stomach.

HCL is responsible for the chemical breakdown of protein in the stomach, and providing the semi digested foods the  acidity necessary to allow to pass into the next stage of digestion.

Without adequate acidity in the stomach, the undigested  foods will sit in the stomach rancidifying before being forced into the next stage of digestion.

When this undigested sits in the stomach normally it would be such an acidic environment that bacteria couldn’t survive.

In a lower acidity environment  it creates a perfect environment for bacterial overgrowth and  digestive dysfunction.

Because these food are improperly digested the likelihood that they will absorbed and used properly will be diminished.

These improperly digested foods are more likely to irritate the gut leading to leaky gut and causing food allergies.

With a reduced metabolic rate  and thyroid function, bowel transit time will become much slower and constipation can become a significant digestive problem.

Nutrient Deficiency

Stress of any kind will deplete the body’s reserve of nutrients and in turn increase the need for those same nutrients in the body.

Being in a ketogenic state for too long, and any kind of caloric restriction are both stresses for the body to manage which will increase the need for nutrients that have been depleted through stressors.

With impaired digestive function the capacity for the body to absorb and use nutrients from the diet when they are consumed will also be lowered.


In Conclusion

I think that low carb and ketogenic diets have benefits in the right context for the right person, but there are also some potential drawbacks that should be considered as well.

Ketosis may be a good starting point for you, but as you get closer to your goal including more carbohydrates can be a benefit.

As someone’s spectrum of health changes so do their needs, and their approach to nutrition should reflect that.

If you decide to try a ketogenic diet I believe the best approach is to use a cyclical ketogenic diet (CKD).

With CKD you eat ketogenic most of the week then carb load by eating lower fat and higher carb 1-3 days out of the week depending on your needs.

A CKD approach allows you to make sure that the metabolism and leptin stay high, hormonal functions doesn’t drop, you blunt the stress hormones for a day and you allow the muscle and liver to refill glycogen stores.

Keep in mind that a ketogenic diet is one of many different dietary approaches you can use. If all you have is a hammer, everything looks like a nail. Always look to expand your nutrition tool belt folks.

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