Ketones: The Key to Metabolic Health and Wellness?

As high-fat, low-carbohydrate diets have grown in popularity, words and phrases like "ketogenic diet, "ketosis, "keto or fat-adapted," and "ketogenesis" have entered the popular conversation, but ketones are nothing new. Let’s review some of these terms.

Low-Carb Ketogenic Diet

A ketogenic diet is formulated by looking at the relative ratios of the calories provided by macronutrients. Fats must provide at least 70% of the calories in order for the diet to be functionally ketogenic, with protein and carbohydrates providing the remaining 30%.

Because fats pack more calories per gram than carbohydrates or protein, this is easier than it sounds. In addition, if your diet provides slightly fewer calories than what you burn every day, the balance will be provided by your body fat, making your diet ketogenic even if it doesn’t quite meet this percentage of fat content.

Ketogenesis

This is a chemical process where the body, specifically the liver, converts fatty acids into ketones for fuel instead of glucose. When in circulation, these are known as “ketone bodies.” This is an ancient metabolic pathway.

Ketosis

This metabolic state occurs when significant amounts of ketone bodies are concentrated in the blood or urine. Ketone bodies are always found in the blood in low concentrations but increase when eating a low-carbohydrate diet or fasting (or starvation).

We can infer that ketosis is when the body burns ketones for fuel rather than glucose. Ketosis that results from a low-carb high-fat diet is known as nutritional ketosis. This is in contrast to what can happen to a type 1 diabetic whose ketone levels get very elevated, which is ketoacidosis and is a medical emergency.

Ketone bodies

These are the actual molecules of ketones that the body can use for fuel.

Fat-Adapted Is Not the Same as Keto-Adapted

Fat adaptation occurs when the amount of carbohydrate eaten is low enough to allow the body to burn fat—removing, for example, all refined and natural sugar from the diet and most carbs, but not necessarily a severe carb restriction. This can be helpful for weight loss but does not necessarily put the person in a state of ketosis, where the body is producing and using ketones for energy.

Burning fat as fuel is not the same as making fuel from fat. Ketogenesis is the building of ketone bodies. An individual who is keto-adapted uses the metabolic pathway of ketogenesis.

When a person is keto-adapted, many different benefits occur across many systems in the body. Keto-adaptation implies that the body is burning ketones for energy, which conveys anti-inflammatory benefits, lowers triglyceride, oxidative stress, insulin and glucose levels, and provides the brain with a stable source of energy.

A person may be fat-adapted but not keto-adapted. Someone who is keto-adapted is also fat-adapted.

Following the Fuel Rule

The human body can burn a mixture of available fuels, but it does prioritize the oxidation of the more volatile fuels first. The body must first draw down available alcohol (if present) and sugars from the bloodstream, then it can use glycogen stores in the liver.

As the sugars are used up, the body will switch to burning more fats and lipids available in the bloodstream. That’s the reason for restricting carbohydrates to 30 grams per day or less. When the body burns fats for fuel, it’s known as being “fat-adapted.”

When carbohydrates have been used for fuel, and the need for more fuel exceeds the availability of more glucose, the liver converts body fat into ketones such as beta-hydroxybutyrate (BHB) and acetoacetate for fuel. This is when someone is “keto-adapted.”

Early Humans

Evolutionarily speaking, our pre-agricultural ancestors probably spent most of their lives in ketosis. For most of our evolution, humans hunted animals, consumed meats and fats, walked great distances, and maintained a general balance of dietary fat and stored fat consumption.

Only when seasonal fruits, starchy roots, honey, berries, and other carbohydrate sources were available did the human metabolism switch from burning fat to burning glucose and storing fat. With carbohydrates available, the body protects its fat stores and packs away as much additional fat as possible—because fall fruits mean that winter is coming!

With this metabolic knowledge, low-carb diets can be used as an effective tool to regain health and wellness.

Health Benefits

As noted above, humans have existed in a state of ketosis for millions of years. If humans had continued to consume the same high-fat, low-carb ratios that we have evolved to consume, the world's metabolic health would no doubt be better.

But as humans moved toward agricultural and industrial societies, grains and sugars became a larger and larger percentage of the diet, and we spent less time consuming/burning fat and more time storing it for future emergencies, which now rarely come.

In years past, ketogenic diets have been used to manage many diseases, including obesity, type 1 and type 2 diabetes, and epileptic seizures. But as various drugs and treatments were developed, including insulin, doctors and patients alike moved away from low or no-carb diets and the natural advantages of ketones.

There has been a lot of interest in ketogenic diets in recent years. A May 2021 article in the journal Nutrients reviewing the potential benefits of a ketogenic diet posits that the diet may help gut bacteria biodiversity, act as an adjunct therapy in cancer treatments, affect gene expression, improve lipid panels, help with weight loss, and help manage blood sugar and insulin resistance as seen in metabolic disease.

Ketogenic diets may also help treat brain-based disorders such as autism, multiple sclerosis, and Parkinson's.

Quick Keto Facts

Ketosis

Ketosis occurs when the body burns fat as fuel by converting stored fat to ketones, like beta-hydroxybutyrate or BHB.

Keto-Adapted

When keto-adapted, a person burns ketones efficiently, reducing the need for glucose. People often remark that in this state, they experience fewer cravings for carbs.

Regaining Health With a Low-Carb Ketogenic Diet

Ketones, ketogenic diets, and ketogenesis are nothing new. Over the last few thousand years—and especially the last couple of centuries—the move toward high grain, high sugar, starchy diets has caused various metabolic illnesses and diseases to flourish.

The move away from healthy fats and cholesterol to the standard American diet has only served to promote metabolic illness around the globe.

A low-carb diet helps us return to the natural metabolic processes that have allowed humans to adapt and thrive in a wide range of environments for over two million years.