Our metabolic rate is the number of calories we spend at rest and during activity every 24 hours.
It varies from person to person of course but on average a female of normal weight will spend around 12 or 13 hundred calories at rest over a 24 hour period. As she will not be at rest for 24 hours (presumably) she will spend additional calories in activity.
If she is a mostly sedentary person she will spend an additional 500 or six hundred calories over 24 hours so her total 24 hour expenditure will be not much more than 1800 calories.
If she is an active person she will spend in excess of 2,000 calories depending on just how active she is. An athlete for example can spend in excess of 3,000 calories in a typical 24 hours.
A calorie is simply a unit of energy (the amount of energy required to raise the temperature of 1 gram of water by 1 degree centigrade) and all food contains calories. If we consume more calories than we need for energy, the rest are stored away in our fat cells for when we need them! If we never need them, they remain in the fat cells as fat.
To lose weight therefore is quite simple. Spend more calories than we consume to make the body release some of the stored energy in our fat cells.
To lose one pound of fat from our fat cells each week (that’s four stones in a year) we would need to spend just 500 calories each day more then we consume. That’s because every pound of fat in our fat cells is actually 3,500 calories. So in simple terms what that means is that someone who has a metabolic rate of (say) 2,000 calories per day, just needs to consume no more than 1,500 calories each day to lose a pound of fat each week.
For more info on how your diet should be based on your metabolic rate, ask your Instructor who will be happy to help.