Metabolism is defined as the bodily processes needed to maintain life. But when people talk about metabolism, they usually aren’t talking about a long list of physical and chemical processes—which is the actual definition of metabolism. We often use the word “metabolism” to describe the rate at which our bodies burn calories.
This is the rate at which your body converts food into energy (calories) and then uses the energy to perform essential and non-essential daily functions. The rate at which we burn calories or burn energy is called metabolic rate.
Your metabolic rate might change from day to day depending on your activity level, but your basal metabolic rate stays fairly steady. Your basal metabolic rate is the number of calories needed to fuel your body’s essential functions, like breathing and circulating blood.
Basal metabolic rate is the most significant component of your total metabolic rate.
While there’s some truth to this, other factors — such as how much you eat and exercise — play a much bigger role in your weight than your metabolism does. And while it’s true that how much lean body mass you have can affect how many calories you burn at rest, its effect is limited — in part, because you can build only so much lean muscle by strength training.
Here are some other facts about metabolism.
What it is
Though the process of metabolism, your body turns the food you eat into the energy it needs. It’s a vital process for all living things, not just humans.
What can affect your metabolism
- Some medications can affect your metabolism — either dangerously speeding it up or slowing it down.
- Eating breakfast every day can jump-start your metabolism.
- Weight loss — especially when it’s rapid — actually slows your metabolism because it takes less energy for your body to function at a lower weight. So, as you lose weight, you need to take in fewer calories or get more physical activity to burn more calories to keep losing pounds.
- Age can slow your metabolism. In general, as you age, you gain fat and lose muscle. Some people also become less active. However, you can do the opposite and take on more physical activity to make up for your slower metabolism.
The bottom line
You can help your metabolism — and your odds of weight-loss success — by changing your energy balance, or the balance between what you consume and what you burn off, through a healthy diet and regular physical activity.