Many “thought-leader” bloggers, social media wellness influencers, and even some credentialed medical professionals espouse the benefits of kicking all sugar to the curb. Stat.  

It’s addictive. It messes with your hormones and increases cravings. It makes you fat. 

Sugar (glucose) can be associated with all of these statements. However, understanding sugar, glucose metabolism, and how your body processes glucose provides foundational knowledge to help you make informed decisions about what’s best for you. It is even more important if you live with chronic illnesses such as diabetes mellitus, hyperglycemia, or metabolic syndrome.

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What is Glucose Metabolism?

Glucose metabolism is the process that cells in the human body use for nourishment and energy. Glucose metabolism begins with the digestion of carbohydrates. The primary role of carbohydrates is to supply energy for your body's cells. Complex carbohydrates are broken down into simple sugars, such as glucose and fructose. When your cells need energy, bonds between carbon atoms in glucose are broken to release energy that your cells can use. 

Since many cells preferentially use glucose for energy, your body can also convert amino acids from proteins and fatty acids into glucose. Excess glucose is stored as glycogen, primarily in the liver and muscles.¹

How Does the Body Process Glucose?

Glucose is a simple sugar. It’s present in the blood (often called blood glucose) and is a major fuel source for organs, tissues, and metabolic processes. 

When we eat sugar, our bodies convert it to glucose to use as a source of energy. As carbohydrates enter the bloodstream, the pancreas releases insulin to be a glucose transporter and shuttle the glucose to the cells for energy or storage. After blood glucose levels reach a post-meal peak, glucose slowly decreases over several hours and returns to fasting levels. Immediately after a meal, glucose removal into the skeletal muscles and adipose tissue is driven by insulin.¹³

Dietary fat and protein can affect your blood glucose as well. Fat isn’t broken down like carbs; it’s broken down slowly into fatty acids. A high-fat meal may have a minimal effect on post-meal glucose and insulin; however, animal research has associated a high-fat diet with an increased risk of insulin resistance.²

While protein is broken down similarly to carbs, it affects blood glucose differently. Protein digestion begins in the stomach and continues in the intestines, where it’s broken down into amino acids. In the liver, some amino acids convert to glucose while others are used to make protein again for muscle use. When adequate insulin levels are present, protein can have a minimal effect on glucose levels. 

Glucose, the body’s preferred source of metabolic fuel, is most readily available from carbohydrates. When carbs are restricted, your body can make glucose from fat (from glycerol) and protein (from the amino acid glutamine) through gluconeogenesis.

Cells' Role in Our Organism?

Glucose metabolism entails the process of glucose entering the tissue cells and converting into adenosine triphosphate (ATP). Glycolysis, the process by which carbs are broken down to produce energy, occurs in the cytoplasm of the mitochondria when one glucose molecule is broken down to form pyruvate to synthesize ATP molecules. 

The body's energy currency, mitochondrial ATP, is used to transport molecules across cell membranes, contract muscles, conduct nerve impulses, divide and grow cells, and create reactions that make hormones, cell membranes, and other vital molecules.