Understanding Our Metabolism

Everyone has a unique metabolism, and the rate of our metabolism is dependent on a number of different factors.

Some people are still under the impression that weight is directly associated with the speed of their metabolism, which is not the case.

Although metabolism does play a role in your body weight, it is not set in stone and is only one small aspect of how your body burns calories and balances energy levels.

What Is Metabolism?

Metabolism is a word that refers to the biochemical processes that our body uses when it converts food (calories) into energy. This happens to support both physical activities and sustain life.

The metabolic process is as follows:

  1. Breathing
  2. Digesting Food
  3. Delivering nutrients to your cells through your blood
  4. Use of energy by your muscles, nerves, and your cells
  5. The elimination of waste products from your body

The rate at which you burn energy or calories is called your metabolic rate, or BMR. Your BMR is the most important component of your metabolic rate and accounts for 60%-70% of your total calories expended daily.

What Factors Affect Metabolism? Understanding Our Metabolism

Everyone has a unique metabolic rate as there is a multitude of factors that can influence just how fast (or how slow) our body converts or uses energy. These factors include your gender, age, size, and body composition, other factors also include whether or not you are pregnant, eating enough, and much more.


Generally speaking, men have a higher metabolism than women. Studies have shown that this could possibly be due to women conserving energy and storing fat more efficiently than men do, on top of this, it also appears that the differences in various hormones also play a role.

There is one reason, however, that men may tend to have a higher metabolism, and that is due to their propensity to carry a leaner mass, which is metabolically active, therefore increasing the metabolic rate. This means that this factor might be mainly due to body composition, and not necessarily sex.

On average, women’s total energy expenditure (when unadjusted for fat-free mass) is on average about 5% to 10% lower than a man – which is partially due to the sex differences in body composition.

Menopause can signify a shift in hormones that have the ability to alter metabolism. After menopause, women will become more insulin resistant and can have decreased levels of estrogens along with increased levels of circulating androgens – all of these hormone changes can directly affect the metabolism.


As we age, our metabolism slows down, and some studies suggest that this is due to the changes in body composition that occur as we get older. You might also gradually lose lean mass while your body fat levels remain the same or even increase. As fat burns fewer calories than muscle, your metabolism can begin to decline.

This lean mass loss can lead to body composition changes, which is a factor regardless of our age.

Body Size / Height

A person’s height can also directly affect the body’s metabolic rate but in very complex ways. Those who are taller tend to have a higher BMR (as they are bigger), but there is research that has shown that when compared to shorter people, taller individuals tend to burn fewer calories when walking relative to their body weight. This is due to more efficient walking by taking longer strides.

Body Composition

Lean muscle mass can burn more calories than body fat, even when your body is resting. Meaning that the more muscle you have – the more calories you can burn over the course of a day, and the higher your metabolism.

Lean mass is also more insulin sensitive and can offer protective effects against metabolic disease.

For obese individuals, energy expenditure can be directly impacted by inflammation. On top of this, high body fat mass can lower the amount of glucose and fatty acids the metabolism uses for fuel. By increasing your lean mass you can reduce this effect and therefore improve metabolism.

To Sum Up

Your metabolism will be slightly different each day, but if you can learn to maintain and manage a healthy metabolism, it can become easier to achieve weight loss and weight maintenance in the long term.

It is important to speak to your doctor or health care provider regarding your weight loss goals and concerns.