What Your Metabolism does and Why it doesn’t actually Affect Your Weight
“Metabolism” is a word that people tend to throw around, but aside from those who are doctors or fitness experts, seldom really understand.
The general belief is that the metabolism is responsible for spending energy and burning calories – that’s not very far from the truth. There are simpler as well as more complex ways to explain what your metabolism is and how it works, but none of them really say it is a fat burning mechanism, as some might think.
Metabolism is the process through which your body transforms what you eat and drink into energy for your basic bodily functions. What this means is that metabolism is really only responsible for taking the nutrients your body needs to perform the passive tasks that keep you alive such as breathing, thinking or pumping blood through your veins.
That is, however, only part of your daily energy consumption. Basal metabolic rate – or metabolism – expends about 70% of your daily caloric intake, but it is not largely affected by how much you eat or the amount of activity you do. In fact, metabolism is only really influenced by your body composition: bigger or more muscular bodies will have higher metabolic rates, as will younger people. Otherwise, your metabolic rate is likely to stay constant all the way through.
Another calorie burning process that stays unchanged is thermogenesis, or food processing. The processes of digestion and those related to it aren’t part of your basal metabolic rate, but they also need energy to function. However, the quantity of energy used for these actions does stay stable, much like the BMR, so it isn’t responsible for weight gain or loss either.
The last process through which your body expends energy is actual physical activity. This doesn’t just mean exercise but also every other action you take - from getting up and brushing your teeth and to walking in or out of the house. Physical activity is where the energy that isn’t needed for the other two processes is used, which means it is responsible for burning excessive calories.
What this ultimately means is that if you’re eating more than your body needs for its basic processes, the only way to get rid of the excess energy is to increase your levels of physical activity. This in turn might actually boost your metabolism slightly because your heart will need to pump more blood, more quickly, and your muscles will need to be rehabilitated frequently. But it still won’t cause any significant change in your metabolic rate – not to the point that it would affect your weight exponentially.
To sum up, the lesson to be taken here is that while your metabolism is in fact responsible for burning most of your calories, it won’t affect weight gain or loss except in very specific cases such as chronic diseases, because otherwise it is very similar to that of another person of your size, build, sex and age.