The first step in determining how many calories you need to consume is to estimate your Basal Metabolic Rate (BMR), which is the number of calories you need to consume each day to maintain basic body functions.

BMR = Body weight in pounds x 10

For example, a 140- pound woman’s BMR :

140 X 10 = 1400 calories

That means to maintain her weight, a 140- pound woman well, even if she stayed in bed all day, would need to consume 1400 calories a day.

Of course, not many of us spend the day in bed. That’s why we need to add an “Activity Factor” to our BMR.

Activity level

Sedentary               : BMR X .30

Moderately active   : BMR X .50

Very active             : BMR X .75

Let’s say that the 140-pound woman is moderately active:

1400 x .50 = 700 calories

Once you know your Activity Factor, add it to your BMR and then add another 10 percent to that total to account for calories consumed by digestion.

Again, using the 14-poubd Moderately Active woman:

1400 + 700 = 2100

2100  x 1.10 = 2310 total calories to maintain current weight.