If you're trying to lose weight healthily and effectively, this adjusted body weight calculator is the tool for you. You may also find it handy if you're a professional dietitian - as using this calculator will allow you to save time calculating your patient's needs, and thus make your work easier, quicker, and more efficient. Read on to find the adjusted body weight formula, and learn how to calculate adjusted body weight on your own.
What is adjusted body weight?
Adjusted body weight (sometimes abbreviated to AjBW) is a measure used for calculating a person's nutritional needs, popular among dietitians when they are tasked with setting up a weight loss program. It is especially useful when the patient is overweight or obese. As adipose tissue is less metabolically active than lean tissue, using actual body weight for calculating one's energy requirements might result in some overestimations for people above their healthy BMI. Hence, it's often recommended to use AjBW instead.
How to use the adjusted body weight calculator?
To use our calculator, follow these instructions:
- Provide the calculator with your sex.
- Input your height.
- Input your actual body weight.
- The adjusted body weight calculator will use your sex, height and weight to figure out your ideal weight, which is a component of the adjusted body weight formula. Please note that there are several accepted equations used for calculating ideal weight, based on slightly different scientific theories. However, the differences in results are practically negligible, so you shouldn't worry about them. In this calculator, we use the Robinson formula.
- The calculator will use the values you provided to calculate your AjBW and display it to you in the bottom-most field.
How to calculate adjusted body weight?
Of course, our calculator will do the work for you quickly and effectively. Nevertheless, it may be worth knowing how to calculate adjusted body weight on your own - you never know when you will find yourself needing to giving nutritional advice with no device to access our calculator at hand!
To calculate AjBW, the following adjusted body weight formula is used:
AjBW = IBW + 0.4 * (ABW - IBW)
- AjBW is adjusted body weight,
- IBW is ideal body weight,
- ABW is actual body weight.
Ideal body weight, according to Robinson's formula, is calculated as follows:
- for men:
52 kg + 1.9 kg per every inch over 5 feet
- for women:
49 kg + 1.7 kg per every inch over 5 feet
Calculating adjusted body weight - example
Let's say we want to determine the nutritional needs for a man who is 180 centimeters tall and weighs 90 kilograms. From the ideal weight formula, we get that his ideal weight would be 72.65 kilos. So we know that:
IBW = 72.65kg
ABW = 90kg
All we need to do is input these numbers into the adjusted body weight formula:
AjBW = 72.65kg + 0.4 * (90kg - 72.65kg) = 72.65kg + 0.4 * 17.35kg = 72.65kg + 6.94kg = 79.59kg
Now we know that when it comes to setting up a daily diet, this particular man should be treated as if he weighed 79.59 kilograms.
Limitations of the adjusted body weight calculator
It's essential to keep in mind that the adjusted body weight calculator is not appropriate in all situations. One should only use it when their excess weight comes from adipose tissue.
For example, many athletes weigh more than their appearance may suggest, and their simple BMIs are theoretically above the healthy level. Their "excess" weight comes from lean muscle tissue. In this case, AjBW does not apply. Also worth mentioning - for such individuals it's recommended to use FFMI, rather than BMI.
Another case where you should not rely on your adjusted body weight to calculate your needs is during pregnancy. If you're expecting a child and you're interested in how it might affect your weight, as well what a healthy diet is for you and your child, please refer to our pregnancy weight gain calculator.