Metabolism: Should You Guess or Measure?

Fitnescity | Should we Guess or Measure?

Whether your goal is to lose, gain, or maintain your weight, knowing your metabolism is extremely valuable for designing an effective and personalized weight management program. Knowing the exact amount of energy that your body uses at rest will help you better understand the amount of energy you need from food.


What is metabolism?

Metabolism is the process by which your body changes the food and liquid you take in into energy for use. 

Your Total Energy Expenditure (TEE) is composed of voluntary and involuntary energy expenditure. It mostly falls under three categories: (1) Resting Metabolic Rate, (2) Thermic Effect of Food and (3) Activity.

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Total Energy Expenditure

Resting Metabolic Rate

The Resting Metabolic Rate (RMR) is a set of measures of your metabolism when you are resting. It is an important piece of information; it shows your Resting Energy Expenditure (REE), which is the minimum number of calories that your body needs to function normally. Your resting metabolic rate is influenced by your age, gender, the amount of body fat and muscle you have, the amount of exercise you do, your ethnicity, as well as by a number of environmental factors such as smoking and climate. Two people with the same weight and height can have very different metabolic rates and energy (caloric) needs. 


Thermic Effect of Food

The process of absorbing food, digesting your meal, and transporting nutrients expends energy. This process is known as thermogenesis, or the thermic effect of food.

The energy you expand as part of this accounts for 5 to 10 percent of your body’s total energy expenditure. Since the rate at which you expand energy naturally decreases later in the day, food has a higher thermogenic effect when eaten earlier in the day.

The thermic effect of food is increased more with a high protein meal than with by a high fat meal. Also, spicy food can enhance and prolong the thermic effect of food. Meals with chili and mustard increase the metabolic rate more than non-spicy food, and this effect may last more than three hours. 



The energy you expand from physical activity is the most variable component. It ranges from small movements like shivering to larger activities like heavy exercise. The rate at which you spend energy through physical activity depends on the duration, intensity and frequency of the exercise. Energy expenditure is also influenced by body weight; a heavier person will expend more energy.


Other Factors

Other factors may have an impact on your energy expenditure. For instance, endocrine disorders, emotional excitement or stress, pregnancy and menopause can change your metabolic rate.

There are also a few factors than can increase your metabolism in a short-lived manner. This includes caffeine, nicotine, alcohol and fever.



If you want to lose weight, the total number of calories that you consume should be lower than your total energy expenditure (which is about the total of the three factors mentioned above).



Curious about how your body expands energy?