Our current understanding of the human diet is built around the existence of three macronutrients. Macronutrients are essential components of our diet that provide us with the energy needed for daily activities and bodily functions. They are called “macro” because our bodies require them in large amounts as opposed to micronutrients like vitamins and minerals. 

The three main macronutrients are carbohydrates, proteins and fats. To maintain optimal health and to feel great throughout the day, humans need a balance of these three nutrients.

But what if there was a fourth macronutrient we could ingest to supercharge our health and well-being? A recent white paper published by UC Davis has proposed that ketones may be the fourth macronutrient.

What Are Ketones?

Our liver naturally produces organic compounds known as ketones to use as an energy source when our body runs low on glucose. This can happen when we are in a fasted state or following a strict ketogenic diet that significantly reduces the amount of carbohydrates (i.e., sugar) we eat. The body even produces low levels when we’re asleep. 

The three main types of ketones are acetone, acetoacetate, and beta-hydroxybutyrate (BHB). 

Acetone is a by-product of ketone production and can’t be used as an energy source. It’s responsible for the fruity breath odor often associated with ketosis. 

Acetoacetate can be converted into either BHB or acetone, depending on metabolic processes in the body.

Beta-hydroxybutyrate (BHB) is produced by the liver from fatty acids when carbohydrate intake is limited. It is an alternative energy source for the brain and muscles when glucose levels are low. 

Understanding Macronutrients and the Role of Ketones

As noted above, macronutrients are the three primary nutrients our bodies require in large quantities: carbohydrates, proteins, and fats. There are subsections within each category (like unsaturated fats vs. trans fats), which can differently impact health and function. 

Micronutrients are differentiated from macronutrients, as they are required in much smaller quantities and do not serve as a meaningful energy source. Vitamins and minerals fall under this category. Each macronutrient uniquely provides energy, supports growth and development, and maintains various bodily functions.

• Carbohydrates (carbs) are the body’s primary source of energy. They are found in grains, fruits, vegetables, and legumes. Once in the digestive system, carbs break down into glucose—commonly considered your body’s preferred energy source for your cells, tissues, and organs. 
• Proteins build and repair tissues and support immune function. Common protein sources include meat, poultry, fish and dairy products, with nuts and seeds also providing slight to moderate amounts of protein. Proteins break down into amino acids, which the body uses to make new proteins that grow and repair tissue, build muscles and convert into energy when the body is very low on glucose.
• Fats also provide energy and help absorb fat-soluble vitamins. They are found in oils, butter, avocados, nuts, fatty fish and animal products such as meat. Fats break down into fatty acids, one of the most efficient forms of energy. They are also used for hormone synthesis.

Interestingly, while you need to consume many of these macros through food (essential nutrients), your organs also produce some of these nutrients (non-essential).

Why consider ketone bodies as a fourth macronutrient?

Classifying ketones has been an interesting process. They have not been traditionally categorized as macronutrients for a critical reason. While ketones are organic molecules used for energy, they haven’t been historically available for consumption as food. This is despite ketones making up 5-20% of the body’s total energy expenditure.

So, while they behave and fill the same roles as other macronutrients, we have to rely on our bodies to synthesize them, much like other “non-essential” macros that are created by various organs.

For most of human history, we have naturally accessed the fourth macronutrient, ketones, very frequently. Because humans often didn’t have access to consistent food sources, our bodies would naturally enter into a state of ketosis. 

However, our diets have changed since the Industrial Revolution and the advent of food manufacturing. As a species, humans have become increasingly ketone-deprived. This is unfortunate because ketones are a unique energy source that can allow us all to unleash our extraordinary potential. In fact, with the development of exogenous ketones, many suggest that ketones may be considered the fourth macronutrient, with the ability to favorably impact health and performance. 

What is Ketone Deficiency, and Why Is It a Problem?

Much like every other macronutrient, the amount of ketones consumed/available can impact our health. But why?

One of the key advantages of using ketones as an energy source is their ability to provide a more sustained and stable form of energy compared to glucose. This particularly benefits athletes and individuals engaged in high-intensity physical activities, as ketones can help enhance endurance and improve overall performance.

The body uses macros to regulate various bodily functions beyond energy production. Ketones optimize organ performance and protect from inflammation and injury. They also have a multitude of neuroprotective benefits. Research suggests that they may have neuroprotective properties and could even benefit people with conditions such as epilepsy, Alzheimer’s disease and Parkinson’s disease.

How To Access Ketones

So, how do you take advantage of ketones? Let’s review three common ways modern humans can access ketones.

1. Keto diet

The keto diet is one of the most popular ways to take advantage of the power of ketones. The keto diet, short for ketogenic diet, is a low-carb, high-fat eating plan that has gained popularity in recent years. The keto diet’s main goal is to shift the body’s primary fuel source from carbohydrates to fats. By reducing carbs intake and increasing fat consumption, the body enters a metabolic state called ketosis.

During ketosis, the liver produces ketones from fats as an alternative energy source. The body then uses these ketones for fuel instead of glucose derived from carbohydrates. 

The keto diet typically consists of foods rich in healthy fats like avocados, nuts, seeds, fatty fish, and oils. It restricts or eliminates carbohydrate foods such as grains, sugars, starchy vegetables and most fruits.

It’s important to note that you should consult with a healthcare professional or registered dietitian before starting any new dietary regimen

2. Intermittent fasting

Various forms of fasting have been gaining popularity due to their many benefits, including weight loss, cognitive benefits and increasing the levels of ketones in the body. During fasting, glycogen stores in the liver are depleted, prompting the body to use stored fat as its primary energy source. Ketone bodies are produced and released into the bloodstream as fat is broken down.  

Fasting can benefit many, but it should be approached cautiously and under proper guidance from healthcare professionals or nutritionists. Individual needs may vary based on age, medical history and overall health status.

3. Exogenous ketones

The third method to access ketones is a more cutting-edge (and more accessible) approach. While pure ketones aren’t naturally found in food, scientists have developed ways of creating exogenous ketones (meaning produced outside the body). This means we can finally consume ketones like we do other macronutrients.

We have provided a more in-depth exploration of exogenous ketones, but as a quick overview, these ketones typically come in the form of powders or liquids. They can be consumed alongside or instead of following a strict ketogenic diet.

Exogenous ketone aids provide an immediate source of ketones to the body, helping to induce and quickly maintain an acute state of ketosis. This can be particularly beneficial for individuals who may find it difficult to achieve or sustain nutritional ketosis through diet or fasting. They come either as salts or esters.

Ketone salts are compounds in which ketones are combined with mineral salts. When ingested, the body breaks down the salts into ketones and minerals. The ketones then enter the bloodstream and provide an alternative energy source to glucose for cells throughout the body. 

On the other hand, ketone esters are chemically modified compounds with a ketone molecule bonded to an alcohol molecule. Unlike ketone salts, esters do not require further breakdown in the body before they can be utilized as fuel. Instead, they are rapidly absorbed into the bloodstream and metabolized directly into ketones. 

It is always a good idea to consult with a healthcare professional before incorporating dietary aids and exogenous ketones into your routine, especially if you have any pre-existing medical conditions,  including diabetes, or take medication.

Unleash Your Extraordinary Potential with Ketones

Nutrition is the backbone of our health, providing us with the energy and clarity we need to become our best selves. The natural decline of ketone production within our bodies after the industrialization of food production, coupled with the reduction in periods when we go without food, has reduced the natural use of ketones.  

Luckily, we can take advantage of ketones and actualize our extraordinary potential through diet, fasting or supplementation.