Amino Acids: Friend Or Foe On Keto?

Amino acids are the building blocks of proteins and can be categorised into three types: essential, non-essential, and conditional. They can be further classified as ketogenic amino acids, glucogenic amino acids, or both, depending on their catabolic reactions. Ketogenic amino acids are broken down to form ketone bodies, which provide energy when glucose is insufficient in the body, a process called ketogenesis. This is particularly relevant for those on the keto diet, which is an extremely low-carbohydrate diet that trains the body to burn fat more efficiently. As such, some people wonder if amino acids can improve the results of the keto diet.

Amino acids can be categorised as exclusively ketogenic, exclusively glucogenic, or both

Amino acids are the building blocks of proteins. They can be categorised into three groups based on the end products produced during amino acid metabolism: exclusively ketogenic, exclusively glucogenic, or both.

Ketogenic amino acids are a subset of amino acids that cannot be converted to glucose and instead give rise to acetoacetic acid or acetyl-CoA. The only two amino acids that are exclusively ketogenic are lysine and leucine. These amino acids produce acetyl-CoA or acetoacetyl CoA without any glucogenic byproducts.

Glucogenic amino acids, on the other hand, can be converted into glucose through a process called gluconeogenesis. This occurs in the liver, where muscle cells release alanine, a glucogenic amino acid, when blood glucose levels fall, such as during fasting or intense exercise. There are 13 amino acids that are exclusively glucogenic.

Some amino acids fall into both categories and are known as "switch hitters". These amino acids can yield both glucogenic and ketogenic products when catabolised. There are five amino acids that are considered "switch hitters": isoleucine, phenylalanine, threonine, tryptophan, and tyrosine.

Understanding the role of amino acids in the keto diet is important as they can enhance metabolic processes responsible for ketogenic weight loss. Additionally, essential amino acid supplements that include the ketogenic amino acids lysine and leucine can help protect against protein insufficiencies that may occur when following dietary restrictions, such as the high-fat, moderate-protein requirements of the keto diet.

Amino acids are the building blocks of protein

Amino acids are made up of one or more linear chains of amino acids (called polypeptides). There are 20 types of amino acids commonly found in proteins. They can be thought of as different flavours that get linked together like beads on a string to make long chains that we call polypeptides, and those are the building blocks of proteins.

The basic structure of an amino acid is a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and a variable component called a side chain. Within a protein, multiple amino acids are linked together by peptide bonds, thereby forming a long chain. The linear sequence of amino acids within a protein is considered the primary structure of the protein.

The side chains of amino acids have different chemistries. The largest group of amino acids have nonpolar side chains. Several other amino acids have side chains with positive or negative charges, while others have polar but uncharged side chains. The chemistry of amino acid side chains is critical to protein structure because these side chains can bond with one another to hold a length of protein in a certain shape or conformation.

Amino acids are ultimately the building blocks of protein, providing a crucial role in repairing health and protecting your body from diseases. Studies have also shown several health benefits when taken in concentrated doses, such as in supplements. By incorporating foods that are filled with amino acids, you will see improvements in your mood, sleep, athletic performance, and muscle gain.

Ketogenic amino acids can be converted to water-soluble compounds called ketone bodies

Ketogenic amino acids are amino acids that can be converted to water-soluble compounds called ketone bodies. Ketone bodies are produced when the body has limited access to glucose and must use alternative methods to create energy. This process is called ketogenesis.

Ketogenic amino acids can be degraded directly into acetyl-CoA, which is the precursor of ketone bodies. From the citric acid cycle, ketogenic amino acids can be degraded directly from pyruvate into acetyl-CoA, a pyruvate dehydrogenase process. They are then further catabolized into acetyl-CoA and acetoacetate, and then into three ketone bodies: Acetoacetate, Acetone, and β-hydroxybutyrate.

Ketogenic amino acids follow the ketogenic metabolic pathway, where the amino acid is introduced into the body and then degraded into water-soluble ketone bodies, which are easier to transport in the body for energy.

Ketone bodies, specifically β-hydroxybutyrate (βHB), aid in the renewal of myelin for demyelinated axons. This is important for individuals with multiple sclerosis (MS), a condition where the immune system attacks the myelin sheath that insulates nerves.

In humans, two amino acids are exclusively ketogenic: leucine and lysine. Five more are amphibolic (both ketogenic and glucogenic): phenylalanine, isoleucine, threonine, tryptophan, and tyrosine. The remaining thirteen are exclusively glucogenic.

Amino acids can be further categorised as essential, non-essential, and conditional

Amino acids are organic compounds that combine to form proteins, which are the building blocks of life. There are 20 amino acids that our body uses to synthesize proteins, and these can be further classified into three groups: essential, non-essential, and conditional.

Essential amino acids are those that cannot be synthesized by the body and must be obtained from food. There are nine essential amino acids: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Non-essential amino acids, on the other hand, are those that our bodies can produce even if we do not obtain them from our diet. Examples of non-essential amino acids include alanine, asparagine, aspartic acid, and glutamic acid.

Conditional amino acids are those that are usually not essential but become essential during times of illness or stress. For example, individuals with the disease phenylketonuria (PKU) cannot synthesize tyrosine and must obtain it from their diet. Other conditional amino acids include arginine, cysteine, glutamine, glycine, ornithine, proline, and serine.

The distinction between these categories is important when considering dietary requirements, as a lack of one or more essential amino acids can lead to protein deficiency, affecting various bodily functions and overall health.

In the context of a keto diet, amino acids can play a role in enhancing metabolic processes and improving results. Ketogenic amino acids can convert to acetyl-CoA, a precursor of ketone bodies, which are small fuel molecules that the body uses for energy when it does not have access to significant amounts of glucose. Leucine and lysine are exclusively ketogenic amino acids, meaning they only produce ketone bodies without any glucogenic byproducts. Additionally, branched-chain amino acids (BCAAs), including leucine, isoleucine, and valine, can be particularly beneficial for keto dieters who engage in physical training as they can help reduce exercise-related muscle damage and soreness.

Ketogenic amino acids can be broken down to form ketone bodies

Amino acids are the building blocks of proteins. They can be categorised as exclusively ketogenic, exclusively glucogenic, or both. The glucogenic group is the most predominant, with 13 amino acids. The carbon skeletons that result from the breakdown of glucogenic amino acids can be used to synthesise glucose. These are not the amino acids that will derive energy from the body's pre-existing fat stores.

The second-largest category contains five amino acids that, when catabolised, can yield both glucogenic and ketogenic products. Exclusively ketogenic amino acids only produce ketogenic products. Lysine and leucine are the only two amino acids that produce acetyl CoA or Acetoacetyl CoA without any glucogenic byproducts.

Acetyl CoA (the precursor of ketone bodies) and Acetoacetyl CoA are the first steps of the Krebs Cycle of energy production. To access citrate synthase, the catalyst of this cycle, without glucose or carbohydrates is the value of ketogenic amino acids.

Ketogenic amino acids are a subset of amino acids that cannot be converted to glucose and instead give rise to acetoacetic acid. Ketogenic amino acids form acetoacetate or acetyl CoA. Glucogenic amino acids form pyruvate, α-ketoglutarate, succinyl CoA, fumarate, or oxaloacetate.

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