So how does JXCirrus CalCount figure out what your weight range should be, how manu calories you should consume and burn off, and how much fat, sodium and other nutrients should you take in?
Well here goes...
JXCirrus CalCount gives you a fairly rough estimate of what your weight range should be using a calculation called the Body Mass Index, or BMI.
BMI = (weight in kg) / ((height in m)x(height in
m)
For you to be in your target weight range, your BMI should be between 18.5 and 25.
JXCirrus CalCount uses your height and the BMI range to calculate what your weight should be.
People 18 years our younger are a bit more complex. BMI doesn't really work form them. Instead, they should be between the 5th and the 85th percentile for weight against height in the growth charts. JXCirrus CalCount uses these growth charts to calculate weight range.
Important Note: The computer uses your height to calculate what your healthy weight range should be. It uses the Body Mass Index (or BMI). Despite the fact that the computer can use BMI to calculate your healthy weight range, we don't recommend it - You are much better off getting your doctor, nuritionist, or personal trainer to give you a target range. The reason is that BMI is pretty inaccurate - It tends to be just plain wrong for about 1/3 of people!
Before you get all cranky with JXCirrus CalCount and demand to know why it is using something that isn't accurate - The reason is that it needs some idea of your weight range to know whether you should be trying to lose weight, gain weight, or just stay the same. Without a target range, it has no idea. There are much better ways to figure out the range, usually by measuring how much fat you have on various bits of your body, and that needs special equipment (a bit beyond a humble app).
So what we are trying to say here is: If you have been given a weight range by some sort of medical professional, then use that value. If you are serious about getting your weight right, then find out from your doctor what your weight should be. But, if you just want to use the BMI value, then be aware that it is very limited.
Some examples:
Calories are a little bit more complex than weight.
JXCirrus CalCount first starts out with a value called Basal Metabolic Rate, or BMR. This is the number of calories that you need to just exist. If you were lying in bed all day, and you wanted to stay at the same weight, you should eat calories equivalent to your BMR.
For Women: BMR = 655 + (9.6 x weight in kg) + (1.8 x height
in cm) - (4.7 x age in years)
For Men: BMR = 66 + (13.7 x weight in kg) + (5.0 x height
in cm) - (6.8 x age in years)
Now, most of us do not just lie in bed all day. Even if we just go to work and back, we burn more calories than our BMR. So to match our BMR to our lifestyle, we need to multiply it by a factor.
If you are sedentary: BMR x 1.2
If you are lightly active: BMR x 1.375
If you are moderately active: BMR x 1.55
If you are heavily active: BMR x 1.725
Now, BMR isn't infallible, but it is at least a lot more accurate than BMI (see above).
JXCirrus CalCount could just leave it there and have you keep your weight as it is. But it doesn't. If you are above your target weight range, it recognises that you need to lose weight, so it will get you to eat less calories than your BMR. If you are under your target weight, it will get you to eat more, to get you up to your weight range. Eating 500 fewer calories in order to lose weight is recognised as a good amount in order to lose/gain weight without doing it all too fast. So...
If you are overweight: Your calorie range will be from 750
under BMR to 250 under BMR.
If you are underweight: Your calorie range will be from 250
over BMR to 750 over BMR.
If you are on your target weight: Your calorie range will
be from 250 under BMR to 250 over BMR.
NOTE: If you set a weight goal, that goal will define the rate you want to lose weight.
Now... This will not guarantee you to lose/gain weight. Different bodies have different metabolisms. So if your doctor gives you a calorie range, use that. But this calaculation works reasonably well...
Once we have calories figured, we can calculate carbohydrates and fat:
The rest of the nutrients are calculated based on government recommendations:
These will change depending on your age and sex (and sometimes if you are pregnant).