Human metabolism is the process that helps the body convert food into energy. The words 'metabolism' refer to all the chemical processes that take place in the human body that release or use energy. These processes are essential for survival as they allow food to be digested, new cells to be produced and energy to be generated.

Every cell in our body needs nutrients to produce energy called ATP (adenosine triphosphate). The process by which what we eat is converted into energy is called metabolism and takes place in three main ways: 

- catabolism, 

- anabolism,

- intermediate metabolic pathways.

 

What is catabolism?

Catabolism is the process by which cells break down complex molecules into smaller ones to release energy. In the context of metabolism, catabolism refers to the breaking down of large molecules into smaller molecules such as amino acids, glucose and fatty acids to produce energy. Read more about what amino acids are and their importance here. If you eat a balanced diet, catabolism accounts for about 10% of your daily calorie intake. With age, the body's ability to break down large molecules gradually decreases. This means that as we age, our body needs fewer calories to maintain the same rate of catabolism compared to younger age. In other words, as we age, we need fewer calories to stay healthy and maintain a healthy weight than when we were younger.

 

What is anabolism?

Anabolism is the process by which cells add new molecules to form larger molecules. In the context of metabolism, anabolism refers to the building of molecules using energy. This energy is generated by the catabolic process. Anabolism is responsible for muscle growth. With proper training and nutrition, anabolism can be stimulated by resistance exercise, a process where we challenge the muscles by exerting low force on them, lifting weights. This will stimulate your body to build new muscle tissue to compensate for the strain placed on the muscles during these exercises.

 

What is intermediary metabolism?

Intermediary metabolism involves the chemical reactions that take place between the breakdown and formation of molecules. These metabolic pathways are essential for converting food into energy. 

The human body converts ingested food into energy through a process called cellular respiration. This process takes place in the mitochondria (oval-shaped organoids enclosed by two membranes, read more about what mitochondria are here.), the energy 'powerhouse' of every cell. 

There are three main stages of cellular respiration: 

- Glycolysis, 

- the citric acid cycle, 

- oxidative phosphorylation. 

In the first stage of cellular respiration, known as glycolysis, food molecules are converted into ATP molecules together with lactic acid. In the second stage, called the citric acid cycle, the hydrogen from the food molecules is used to produce ATP and electrons. The electrons are transferred to oxygen to form water molecules and CO2. The third step, called oxidative phosphorylation, produces ATP from the hydrogen produced in the first step and CO2 produced in the second step.

 

How does human metabolism depend on exercise?

Exercise is very important for metabolism because it stimulates the body to break down carbohydrates, fats and proteins into energy. For example, when you run or do any aerobic exercise, the body breaks down glycogen (a carbohydrate) in the muscles and converts it into ATP, which is a source of energy. Once the body has used up the glycogen stored in the muscles (for more information on glycogen, click here), it will start to break down fat stores to provide energy through a process called beta-oxidation. The fitter you are, the more fat you will break down compared to a less physically fit person. This is because the fitter and more muscular you are, the more glycogen you have stored in your muscles.

 

How does a person's metabolism depend on diet?

Diet also plays a big role in metabolism. A balanced diet will help you maintain your metabolism and keep your body healthy. On the other hand, eating a lot of processed foods will lead to the accumulation of excess fat in your body and a slower metabolism. Fibre (plant-based substances, read more about them here) is essential for a healthy gut and also helps the body break down certain molecules. Raw Powders is available in Sea Moss & Bladderwrack capsules. Factors such as protein intake and calorie intake can also affect your metabolism. A high protein intake can help maintain muscle mass and speed up metabolism, while a high calorie intake can lead to weight gain.