Ketogenic diet: the health benefits that you need to know

The ketogenic diet (KD) is gaining popularity for its weight loss effects. Many questions arise when it comes to the additional health effects one may experience from the diet.

This article explains the KD including its history and health benefits. Stay tuned for the rest of this keto-blog series to learn how to get started on the diet, health concerns, and other helpful resources. 

What Is The Ketogenic Diet?

The KD is essentially a high fat, low carbohydrate diet.

Upon successfully following a KD, one can achieve a “ketogenic state.” This is when fat is the primary fuel source for the body.  

There are several ways one gets into ketosis including, fasting, taking MCT-oil, low calorie diets, and consuming less than 50 total grams of carbohydrates per day.

However, the most common way to achieve the KD is eating a very low carbohydrate diet. This can be quite challenging if you’re used to following the Standard American Diet (SAD).

Most Americans eat about 45 to 60% of their calories from carbohydrates. On the other hand, the KD consists of about 5% to 10% of calories from carbohydrates.

Many foods healthy foods you may enjoy have relatively high carb counts (see below).

Keep in mind that once you follow a KD for a certain period of time (2 to 4 weeks), your body transitions to using ketones (products of fat metabolism) instead of glucose (product of carbohydrate breakdown) for energy. Eventually, the adapted ketogenic person no longer struggles and the low carb diet can feel like a breeze!

What Are Ketones?

Ketones are energy molecules that come from the body breaking down fats. 

Not only can you produce ketones during a ketogenic diet, but you can also produce them when you are fasting, enduring prolonged fasted aerobic exercise, or when there isn’t enough insulin to get glucose into your cells (ketoacidosis).

There are three types of ketone bodies:

  1. beta-hydroxybutyrate
  2. acetoacetate
  3. acetone

This picture was taken from Wikipedia

Carbohydrates and The Body  

The body’s main source of fuel generally comes from the carbohydrate foods like grains, starches, and fruits. These foods break down into simple sugars known as glucose.

Thereafter, the hormone insulin spikes so it can bring glucose into cells for energy production.

Did you know carbohydrates are the only non-essential macronutrient? That means a certain amount of essential fats and proteins are necessary for human survival, but carbohydrates are not as necessary as once thought.

When we don’t consume enough carbohydrates, the body compensates by utilizing fats as energy or turning proteins into glucose through gluconeogenesis.

History Of The Ketogenic Diet

The KD was first used in the 1920’s to treat epilepsy.

Researchers noticed that when epileptic patients fasted, their seizures improved within 2-3 days. They soon realized fasting and the ketogenic diet both produced the same ketones: acetone and beta-hydroxybutyrate (1).

By the1970’s, a research report showed the ketogenic diet produced complete seizure control on 52% of the 1,000 children in the study (1).

Once an anticonvulsant drug was made, the need for the ketogenic diet for epilepsy slowly declined and it wasn’t the primary epilepsy treatment. Having children stick to a diet long-term is obviously a bit more challenging then having them pop a pill. 

Today, there is growing literature on the KD for metabolic health, weight reduction, cancer, and suspected increase in lifespan.

Benefits Of The Ketogenic Diet

There are numerous benefits of following a KD outside of epileptic seizure control.  

Weight Loss & Metabolic Syndrome

Numerous studies support the notion that the KD can produce weight loss and metabolic benefits. 

A meta analysis of randomized controlled trials compared very-low carbohydrate ketogenic diets to low-fat diets in overweight subjects. They found subjects on the very-low carbohydrate diet had overall greater weight loss, decreased triglycerides, reductions in diastolic blood pressure, and an increase in HDL cholesterol (2).

These are all risk factors for metabolic syndrome: a cluster of physiologic abnormalities increasing the risk of cardiovascular disease and type 2 diabetes.

Improvement in Epilepsy

Epilepsy is a condition that typically causes uncontrollable seizures.

Many studies exist showing the efficacy of the KD for epilepsy treatment.

One study compared children treated with the ketogenic diet versus children who were failing to respond to anti-epileptic drugs for 3 months. The children on the ketogenic diet had a 50% seizure reduction compared to the control group that had 6% (4).

Managing Polycystic Ovarian Syndrome (PCOS)

PCOS is one of the most common hormonal disorders in women, often causing irregular periods and infertility.

There is a correlation between PCOS and insulin resistance. Therefore, women with PCOS often try to maintain a healthy weight by having excellent blood sugar regulation.

In one study, a group of 11 overweight women with a BMI greater than 27 who were diagnosed with PCOS followed a 20 gram carbohydrate diet for 24 weeks. There was a significant reduction in body weight, free testosterone, LH/FSH ratio, and fasting insulin levels (5).

Diabetic Control

Type II Diabetes is a condition that results in poorly controlled blood sugar and sustained insulin resistance overtime.

Studies show that the KD helps with reducing blood sugar and increasing insulin sensitivity. Both of these can help improve diabetic control.

One study of type II diabetic men on a low carbohydrate diet (30 to 40 grams of carbohydrates daily) for 16 weeks showed a 7% reduction in weight loss and a 16% reduction in hemoglobin A1C. The reductions were so great that some participants were able to stop taking their diabetes medication (6).


The KD has been studied in animals and humans for many different types of cancers. 

However, it seems to have a more positive outcome in reducing tumor growth in animals than in humans. There are some case reports in human studies. In a recent research study, two females with malignant astrocytoma had reduced tumor growth on the KD (7). 

In animal models, most studies show that the KD reduces tumor growth in certain diseases. Those include malignant glioma, colon cancer, gastric cancer, and prostate cancer. This may be due to the fact that cancer cells thrive on glucose and the KD limits this fuel source (7).

Improve Dementia and Alzheimer’s Disease

Beta-hydroxybutyrate, a ketone body elevated during the KD, is known to improve memory (8).

Therefore, many studies show that the KD can improve memory in dementia and Alzheimer’s disease. There are also studies showing a high carbohydrate diet worsening cognition and behavior in Alzheimer’s patients (8).

Support Athletic Endurance

Many athletes“carb load” before a big endurance event to replenish their glycogen (carbohydrate) storage in their muscles and liver.

Researchers are now studying the positive effect of the KD on athletic performance.

In one pilot study, 5 endurance athletes consumed a KD (less than 50 grams of carbohydrates daily) for 10 weeks. Overall, all athletes showed an increase in exercise intensity. They showed an increase in intensity by reducing their average time to exhaustion, increased peak performance and ventilatory threshold (9).

In another study, researchers found cyclists who were on the KD improved values of VO2 max and lactate threshold (LT) VO2. VO2 max is a measurement that allows researchers to see the maximum amount of oxygen a person can utilize during exercise. However, in that same study, researchers found the power output in athletes were reduced on the KD and that could be due to limited glycogen storage (10).

Not only could the KD be beneficial in increasing VO2 max, but it could also be beneficial when specific athletes need to reduce their body mass and body composition in order to make their weight class (10).

Health Benefits of Keto

Overall, there are many health benefits of the KD outside of weight loss.

Not only can the KD reduce metabolic markers, but it can also reduce seizures in epilepsy, manage signs and symptoms of PCOS, reduce tumor growth, improve cognition and memory in dementia and Alzheimer’s disease, and possibly reverse type II diabetes.

It could possibly increase athletic endurance, as well. 

In the next article, you’ll learn more about the KD and what it consists of, things to look out for, safety, and supplements.

Guest Contributor Amanda Cook, MS, CNS Candidate