Metabolism describes all the chemical processes that go on continuously inside your body to keep you alive and your organs functioning normally, such as breathing, repairing cells and digesting food.
These chemical processes require energy. The minimum amount of energy your body requires to carry out these chemical processes is called the basal metabolic rate (BMR).
Your BMR accounts for anything between 40% and 70% of your body’s daily energy requirements, depending on your age and lifestyle. A “slow metabolism” is more accurately described as a low BMR.
There are lots of online calculators that can work out your daily energy needs. Look out for those that use the Harris-Benedict equation.