How Do Hormones Regulate Metabolism?

Each of us has a different, specific metabolism and the way our bodies manage the energy from food. We often hear that some people have a “slow” and some have a “fast” metabolism, which describes differences in the way food and energy are utilized and stored.

Since metabolism describes a rather complex network of various processes, today, we will focus on one segment that strongly influences metabolism: hormones.

What is metabolism?

Metabolism is a term that describes all the biochemical processes and reactions that take place in the body. There are many of them, and some of them are extremely complex. But most often in the context of weight loss, metabolism is used as a term for the way our body produces and uses energy.

Even if we do not do any physical activity during the day, our body needs energy to perform basic life functions. The energy needed for these functions is called basal metabolism, and it is different for each individual.

It is influenced by multiple factors, such as muscle mass, age, gender, body size, hormones, external factors, etc. Genetics also plays a major role in the way our body converts and consumes energy from food.

How do hormones control metabolism?

Metabolism and hormones are intricately linked, as hormones can be said to have one of the central roles in regulating metabolic processes, including the conversion of food into energy, fat storage, etc.

Several hormones such as insulin, thyroid hormones (T3 and T4), cortisol, leptin, and ghrelin influence many different aspects of metabolism.

Insulin, produced by the pancreas, helps regulate blood sugar levels by taking sugar from the blood into cells, as well as storing glucose in muscle and liver cells.

Thyroid hormones, which are secreted by the thyroid gland, are essential for maintaining the basal metabolic rate (BMR), and thus they directly affect energy balance or metabolism.

Reduced levels of thyroid hormones (hypothyroidism) can lead to a slower metabolism, while increased levels of these hormones (hyperthyroidism) can cause a more active, accelerated metabolism.

Cortisol, or the stress hormone, is released by the adrenal glands and can increase metabolic rate in the short term, but chronically elevated cortisol levels (due to chronic stress) can lead to insulin resistance, accelerated fat accumulation, and impaired metabolism.

Leptin and ghrelin are hunger and satiety hormones. Leptin signals the brain when the body has sufficient energy reserves, reducing hunger and increasing energy expenditure. In contrast, ghrelin, often called the “hunger hormone,” signals hunger and reduces energy expenditure when levels rise.

All of these hormones are also involved in complex interactions with each other and create an intricate network that governs metabolic rate, energy balance, and fat storage. Therefore, any disruption in the levels of any of these hormones can significantly affect overall metabolic health.