Weight Control Specs

How do you know what a healthy weight for your body should be? If you are trying to control your weight, several systems specify what your weight should be based on factors such as your height, your body fat percentage and other considerations. These systems have advantages and disadvantages and range from the simple, which you can do easily at home, to the complex, which can only be carried out in the doctor's office. Whatever system you choose, if you plan to make changes in your diet or activity level, it is advisable to speak with a physician before starting. These systems, or "specs" are all guidelines, but they cannot take the place of professional medical advice.

Body Mass Index (BMI)

• Your Body Mass Index (BMI) is a number calculated based on your height and weight. The specific equations is weight in pounds, divided by height in inches, times 703. This gives your BMI number. A BMI under 18.5 is considered underweight, from 18.6 to 24.9 is normal, from 25 to 29.9 is overweight, and 30 and above is obese. While the BMI is a very reliable to determine body leanness and healthy weights, it can be somewhat inaccurate for those who are very muscular and athletic or quite tall.

Body Fat Percentage

• Body fat percentage, which tells you the number of pounds of fat you are carrying versus pounds of lean mass, is another reliable spec for weight control. Healthy fat percentages are different for men and women because women naturally carry slightly more fat than men. Healthy men should have a body fat percentage between eight and 19 percent, and healthy women should be between 21 and 33 percent. Body fat can be measured using a number of procedures, include fat calipers and scales that measure fat through electrically charged foot pads. The most accurate fat percentage tests must be completed in the doctor's office or at a specialized clinic.

Waist Circumference

• Measure just above your navel.

  Waist circumference is another reliable and easy-to-use indicator of being at a healthy body weight. The risk of weight-related diseases increases when men have a waist circumference of greater than 40 inches and women have a waist circumference of greater than 35 inches. To measure your waist, use a sewing tape measure and place it around your belly, just above the navel.

Body Adiposity Index

• A new alternative to BMI introduced in 2011 is the Body Adiposity Index (BAI). This spec measures height and hip circumference to calculate body fat percentage. To calculate your body fat percentage using BAI, take the measure of your hip circumference in centimeters, divide it by the square root of your height times your height in centimeters and subtract 18.