A healthy weight can be determined by using the body mass index and by measuring the circumference of the waist. BMI is intended for people over age 20, according to WebMD.
A BMI is calculated by using the body mass index chart and a person's height in feet and weight in pounds. A BMI less than 18.5 is considered underweight, and it may be due to a medical problem, states WebMD. A registered dietitian may be able to help an underweight person with healthy eating habits.
The recommended weight range is a BMI between 18.5 and 24.9. People in this range must still consider physical activity and healthy eating habits, says WebMD. A person is considered overweight if his BMI falls between 25 and 29.9. This may or may not be unhealthy depending on level of activity, healthy eating practices and muscular build.
A BMI of 30 or higher places a person in the obese category. People in this range should discuss weight loss and eating habits with their doctor, reports WebMD.
Asian people may have a lower recommended weight range. BMI provides a clue into a person's health, but it is only one indicator of overall health, explains WebMD.