7 Factors That Influence Your Metabolism

7 Factors That Influence Your Metabolism

More and more frequently, we hear about the million plus things that we do or eat and how they will affect our metabolism. We hear that when metabolism “slows down,” it is a bad thing and that when it “speeds up,” it is good. Slow metabolism leads to weight gain while fast metabolism leads to weight loss. But, what exactly is it that speeds up and slows down? What things do you do consciously or subconsciously that affect this mysterious metabolic rate?

First of all, what exactly is metabolism?

Metabolism is the encompassing term used to refer to the millions of functions your body has to carry out in order to keep you alive and functioning. Essentially, it is the process that turns what you put into your body through food and drink by combining calories with oxygen, into energy for your cells to use.

Your body needs energy constantly, even when you are at rest. At some moments throughout the day, you need more energy than others, and some people require more energy than others. The amount of energy you need to for your body to carry out basic functions (breathing, heart beat, cell maintenance, etc.) when at rest is called you basal metabolic rate. Your basal metabolic rate takes into account your body size and composition, your sex, and your age. In addition to these, explained below, there are many other factors that influence your metabolic rate.

7 Factors that influence your metabolism 

1. Body size and composition

People who have larger or more muscular bodies tend to burn more calories than a smaller, less muscular person. This is true even if you are at rest. This is because muscle needs more energy to function, even when it is not in use, while fat needs less energy.

2. Sex

Generally, men tend to be larger have less fat than women, so they generally have faster metabolisms. While this isn’t true in all cases, it is true on a population-wide scale.

3. Age

Growing requires a lot of energy, which explains why teenagers tend to have such voracious appetites and babies need to eat so frequently. As we grow older, we stop growing, and we can begin to loose lean muscle mass. Additionally, we grow through some chemical changes that require different amounts of energy and may also favor fat storage.

4. Thermogenesis

Food processing, also known as thermogenesis, is one of the main factors that increases metabolic rate. It refers to the amount of energy needed to digest and absorb foods. This doesn’t necessarily change from one person to another, and it tends to remain steady throughout our lifetimes. According to research, it accounts for 5-15% of daily energy expenditure, where those that had a high protein and alcohol consumption were at the upper end of the scale, while those that consumed a high fat diet were at the lower end of the scale.

5. Physical activity levels

The amount of exercise and physical activity you do in a day affects how much energy you use. This may seem obvious, but it is a very important factor to mention as it is one that is completely pliable. People who spend their day walking, doing physical work, or carrying out exercise have more energy expenditure, and thus tend to have a “faster metabolism” than those who live a more sedentary lifestyle.

6. Genetics

Your genetic makeup determines how your cells are programmed to use energy. This is most relevant in cases of people with certain genetic mutations, as they can result in health problems or abnormal development, thus altering energy needs. Some of these include birth defects, connective tissue disorders, and metabolism of particular substances in the body.

7. Hormones

Hormones are chemical messengers that signal certain processes to start, stop, or keep going. A few of the main hormones that affect energy metabolism are:

  • insulin: they tell the body that glucose (generally from carbohydrates) and amino acids (generally from proteins) are available and ready to process
  • glucagon: they tell the body that glucose and amino acids are scarce, and thus the body has to use energy stores to keep functioning
  • thyroid hormones: increase basal metabolic rate

Different people’s bodies have different “reactions” to these hormones, but in general the messages sent and received are the same. The situations where hormones most affect your metabolic rate is when you happen to have a hormonal disorder. Some examples of this are hyperthyroidism (too much thyroid hormone in the blood), hypothyroidism (too little thyroid hormone in the blood), insulin resistance, and diabetes (chronic insulin resistance). All of these will affect your energy use, and thus your weight.

What can you do to “increase” your metabolic rate?

Many factors that determine your metabolic rate are unchangeable: age, sex, thermogenesis, and your genetics, for example. However there are some things you can do to maintain a healthy metabolic rate throughout your lifetime.

First, exercise regularly. This will not only increase your energy expenditure, it will also increase your lean muscle mass and increase your basal metabolic rate.

Second, eat what is right for you: If you feel you might have a hormonal or metabolic disorder, go to your doctor and get it checked out. This could have an impact on what make up the best diet for you.

Sources:

https://www.med.unc.edu/pediatrics/specialties/genetics-metabolism

http://watcut.uwaterloo.ca/webnotes/Metabolism/hormonesAffectingMetabolism.html

http://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/metabolism/art-20046508

http://www.ncbi.nlm.nih.gov/pubmed/15507147