Metabolism is a constant process that begins when we are conceived and ends when we die. It is a vital process for all life forms, not just humans. Living organisms must accomplish to major functions in order to survive: they have to extract energy from nutrients in forms that they can use immediately or in the future, they have to use nutrients to make building blocks for synthesizing all of the molecules needed to carry out their life functions. If metabolism stops a living thing dies.

METABOLISM


FAST SLOW



It depends in the use of energy in food if it is fast or slow.

It is measured in calories.

The number of calories needed each day varies from person to person and depends on body, mass, age, sex and level of activity. In general males need more calories than females.

If you eat fewer calories than your body can metabolize, you will use some of the energy stored in body fat and lose weigth.

If you eat more calories than your body can metabolize, you will store the extra energy as body fat and gain weight.

Active people need more calories than inactive.