What exactly is going on in your body at the moment? You may just be sitting still and reading this, but under your skin there are all kinds of chemical reactions taking place. Maybe your digestive system is still processing the last thing you ate. Maybe it’s simply that you’re breathing. One thing is certain: you’re never completely at rest. That’s what we call your metabolism.
Metabolism can be hard to describe in detail. Basically, it’s all about how your body converts food into energy that then fuels other processes. Breaking down compounds like glucose to release energy is called catabolism. Anabolism is when the broken-down energy is used to build something new, like growing bone and muscle. Both are essential parts of metabolism without which you wouldn’t even have enough energy to pump blood around the body.
The role of metabolism and the need to keep the body’s internal processes running means that even when you’re not moving, you still need energy. This means you need to consume calories. The number of calories you need to provide energy, even when at rest, is known as your basal metabolic rate (BMR). Messing with your BMR is part of the reason rapid weight loss is often unsustainable.
A fast metabolism or metabolic rate burns more calories quicker. This doesn’t necessarily lead to weight loss because you end up needing to consume more energy to replace the calories and keep your body working. Similarly, trying to build more muscle burns more calories and can therefore increase metabolic rate. This is part of why men often have a faster metabolism than women. Smoking can also speed up your metabolic weight. If you lose muscle as you age, this can slow metabolism again.
Regulation of your metabolism comes in part from your thyroid hormone, as produced by your thyroid gland. Other hormones control when your thyroid gland produces thyroid hormone. Problems with your hormone levels are one of the things that can interfere with your metabolism and metabolic rate. Metabolic disorders, on the other hand, damage the way you process the enzymes and nutrients that your metabolism normally helps work. They’re generally genetic.
Metabolism is very complicated. Trying to understand how it affects your energy levels and weight isn’t easy, but being sensible about what you eat and how you exercise should help it stay at a healthy rate.
