4 minute read

Understanding the chemistry of your metabolism

Published October 12, 2023

Metabolism is the set of chemical processes that take place in your body, from the smallest cell to the largest organ. These processes are responsible for converting food into energy, building and repairing cells, and removing waste products.

You can think of metabolism as the engine that powers your body—it continues working even when you're at rest. Because even during rest, your body still needs energy for its vital functions, from breathing to circulating blood to regulating body temperature. And without metabolism, life wouldn’t be possible.

What’s the body’s chemical balance?

The body's chemical balance means keeping the right amounts of different substances in your body so that everything runs the way it should. This includes minerals in your blood, your body’s acid/base (pH) level, and even hormones that regulate your stress response. When your chemical balance is off, it can lead to a variety of problems like feeling tired, not having enough fluid (dehydration), weight changes, and muscle cramps.

Building and breaking: the reactions of metabolism

When we talk about metabolism, we mean the chemical reactions that are constantly taking place to keep our bodies alive and healthy. Metabolism involves thousands of different chemical reactions, but can be divided into two main categories:

  1. Anabolism is when your body builds things. It uses energy to take small parts (called molecules) and puts them together to make bigger pieces. For example, anabolism is what helps your body grow and strengthen bones, increase muscle mass, and repair tissues. 
  2. Catabolism is when your body breaks things down. It releases energy by taking big pieces and breaking them down into smaller parts. For example, catabolism is what breaks down food into nutrients that can be taken in and used by your cells. 

In other words, anabolic processes are like building a house, while catabolic processes are like tearing one down. Anabolic reactions use up energy, while catabolic reactions make energy. Here are more examples of anabolic and catabolic reactions:


  • Building muscle tissue
  • Repairing damaged cells
  • Producing hormones
  • Storing energy
  • Producing new blood cells
  • Adding minerals back into bones
  • Healing wounds
  • Growing hair


  • Breaking down food into nutrients
  • Digesting carbohydrates (sugars/starches), proteins, and fats
  • Generating energy
  • Removing waste products
  • Breaking down damaged cells
  • Releasing heat

How do anabolic and catabolic processes work together?

Together, anabolic and catabolic reactions work to maintain a balance in your body. They make sure it can build and repair what it needs while efficiently storing and using resources to keep you healthy. For example, when you eat a meal, your body breaks down the food to release energy. This energy is then used to do things like healing wounds, making hormones, and building muscle.

When you're at rest, your body still needs energy to function. This energy comes from catabolic reactions that break down stored energy. This energy is used for things like breathing, pumping blood, and keeping your brain active.

These two processes play different roles in our bodies, and knowing how they work can help you train more effectively to achieve your fitness goals. So, say your goal is to lose weight, you could create a calorie deficit by burning more calories than you consume. This can be done by exercising regularly and eating a healthy diet. When you're in a calorie deficit, your body will break down stored fat for energy, which is a catabolic process.

But if you only focus on breaking down substances in your body without also paying attention to the building-up process, you might lose not only stored fat but also muscle mass. This can happen because your body could start breaking down muscle tissue to get the energy it needs. 

How do hormones affect metabolism?

Hormones are chemical messengers that regulate many bodily functions, including metabolism. 

Any changes to your hormones caused by things like menopause, thyroid disorders, or diabetes can affect these processes. This can affect how your body manages energy, and that can have a say in your overall metabolism and health.

What does a Comprehensive Metabolic Panel have to do with understanding metabolism?

A comprehensive metabolic panel (CMP) is a blood test that measures 14 different substances in your blood to check your body's chemical balance and metabolism. The results of a CMP can provide valuable information about your metabolic health, organ function, and overall well-being. Imbalances in these substances can mean problems with vital organs like the liver and kidneys. Monitoring these markers can also help doctors diagnose and manage a variety of health conditions.

No doctor visit is required to buy your own lab test at questhealth.com. PWNHealth and its affiliates review your purchase to ensure it is medically appropriate before submitting the test order for processing. PWNHealth also reviews your test results and will contact you directly if they require prompt attention. Included in each purchase is the option to discuss your test results with an independent physician; however, you are also encouraged to speak with your primary healthcare provider. 


  1. Britannica. Metabolism. Accessed September 15, 2023. https://www.britannica.com/science/metabolism. 
  2. Healthline. Catabolism vs Anabolism: What’s the Difference? Accessed September 15, 2023. https://www.healthline.com/health/catabolism-vs-anabolism. 
  3. Cleveland Clinic. Anabolism vs Catabolism: The Role They Play in Your Metabolism. Accessed September 15, 2023. https://health.clevelandclinic.org/anabolism-vs-catabolism. 
  4. MedlinePlus. Fluid and Electrolyte Balance. Accessed September 15, 2023. https://medlineplus.gov/fluidandelectrolytebalance.html.