Nutrition
The ketogenic diet has many benefits, but chronic use causes hormonal imbalances affecting thyroid and leptin levels. Learn why cyclical ketosis is superior to constant ketosis and how the edubily approach works.
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After learning about the ketogenic diet last week, today we want to discuss its benefits and limitations.
Admittedly, some research results make a ketogenic diet (KD) appear very attractive. We have previously discussed the application of the ketogenic diet in specific diseases such as epilepsy¹, chronic kidney disease², and metabolic disorders like type 2 diabetes³ and severe obesity⁴.
Throughout these discussions, a ketogenic diet has consistently proven to be a powerful tool with minimal side effects.
In a recent pilot study from Stanford University, the KD even showed promise for psychiatric disorders.⁵ Recent findings suggest that schizophrenia and bipolar disorder may stem from metabolic disturbances that negatively affect synapses and nerve cell excitability.
Forever keto?
We have long been aware that the healing effects of ketone bodies can be a true game-changer for some people with specific conditions. And it is no secret that most people in our society of abundance would benefit from mild ketosis from time to time.
Therefore, we also recommend reducing excessive carbohydrate intake and instead of eating bread and pasta daily, increasing protein and vegetable intake.
But must there be permanent (severe) carbohydrate restriction? In most cases, the answer is «no». The fact that a keto diet carries certain risks is often—intentionally or unintentionally—ignored. More on this shortly.
To lose weight and become metabolically healthier, there are simpler approaches than going straight into full keto…
As a frequently cited 2019 study showed, overweight participants on an unprocessed diet automatically consumed approximately 500 fewer calories daily compared to those given ultra-processed foods.⁶ And notably, people in each group could eat as much as they wanted.
There is no magic behind it: A potato simply keeps you fuller longer than white bread.
Refined flour products are automatically eliminated on an unprocessed diet—and with them, a lot of carbohydrates. And here we are back at the edubily ketogenic approach (see our Instagram post from Monday).
Cyclical, not chronic
Now let's look at what can go wrong with the KD.
First, keto is often misunderstood. Some people think eating ketogenically is a free pass for unlimited butter coffee, salami, bacon, cheese, and cream cake.
At the end of the day, they wonder why the promised weight loss never materializes while their blood lipid values keep getting worse.
If someone already has elevated free fatty acids in their blood due to obesity, they don't need to further overload with dietary fats. Ultimately, you can lose weight just as well with carbohydrates. The key is achieving an energy deficit in the first place and living off your own reserves—the how is secondary.
On the other hand, even a well-designed keto diet has pitfalls. We have mentioned it before: Biology wants to oscillate. Chronic processes, regardless of direction, rarely achieve goals long-term.
Hormonal Effects of Chronic KD
With the growing popularity of the ketogenic diet, the number of scientific publications has grown exponentially since the 2000s. While there were barely 300 publications on KD from its first publication in 1931 through 2000, just last year there were over 600—more than double!
Then there is the matter of hormone balance. Under a strictly low-carbohydrate diet (we're talking under 100 g carbs per day), thyroid hormones decline, specifically T3.⁷ Even iodine supplementation cannot prevent this.⁸
Closely related is the satiety hormone leptin. This drops significantly under an overly carbohydrate-restricted diet.⁹ Low leptin means intense cravings, slowed metabolism, absent libido, and a compromised immune system—to name just a few consequences. Not desirable.
Additionally, testosterone levels in men can decrease during a KD, while cortisol increases.¹⁰ Persistently elevated cortisol is undesirable because this stress hormone can long-term lead to insulin resistance, sleep disturbances, and belly fat deposition.
Famed longevity researcher Valter Longo studied the effects of KD in a mouse model of multiple sclerosis.¹¹ While cyclical ketosis («fasting mimicry») could strongly slow MS progression and even completely reverse it in some animals, a conventional KD only produced «mild improvement»—without halting the disease. Again: cyclical is better than chronic.
Just in May 2024, an animal study revealed another downside of the keto diet.¹² Continuous KD can trigger cellular aging, so-called senescence, in mice. Particularly in heart and kidney tissue, which could lead to premature organ damage. Fortunately, this can be prevented with regular ketosis breaks.
These keto breaks also help restore leptin levels, by the way. Convenient!
Learn the edubily KD approach
Without therapeutic indication, we therefore see no reason for permanent strict ketogenic eating. On the other hand, it is certainly advisable to periodically lower your diet's carbohydrate content to benefit from ketosis's advantages.
This is easy to do—simply have a protein and fat-rich, carbohydrate-light dinner and breakfast. When you wake up in the morning, your ketone bodies are already significantly elevated from the overnight fast.
You can further leverage this state by delaying carbohydrate intake or continuing to avoid refined carbs like flour. It's really no witchcraft, is it? ;-)
Our edubily KD is a gentle method to periodically enjoy ketosis without the disadvantages of extreme carbohydrate restriction. We detailed how to structure an edubily-KD day in our Instagram post.
We wish you success and bon appétit ;-)
