It is important to measure “the fatness” of person. Increased body fat contributes to various medical problems associated with obesity. Body Mass Index (BMI) is the most common and basic method used to determine whether a body is fat or fit. BMI is the ratio of weight to height, calculated as weight (kg),height (m2). The advantages of using BMI are that it is easy to measure, inexpensive and there are standardized cutoff points for overweight and obesity. There is also a strong correlation between BMI &and body fat levels. Also, available evidence from studies suggests that ‘’high BMI’’ predicts higher risk of chronic disease.
But BMI has certain limitations. It is an Indirect and imperfect measurement. It does not distinguish between body fat and lean body mass. The lean body mass includes muscles, organs, skin, and bones. Someone with a higher and healthy muscle mass may be labeled as ” high BMI”. BMI varies with age, so it is not as accurate a predictor of body fat in the elderly as it is in younger and middle-aged adults. It varies with sex as well as ethnicity. At the same BMI, women have, on average, more body fat than men, and Asians have more body fat than whites. So, for accurate measurement of body fat content, other metrics of basic body measurements like waist circumference or waist to hip ratio may be used along with BMI. Scans like Dual Energy X-ray Absorptiometry (DEXA) provide accurate body fat estimates.