Bmi does not measure body fat directly but bmi is moderately correlated with more direct measures of body fat 123. Body mass index is the standard metric for determining who is normal weight overweight and obese but bmi is not an accurate measure of fat and doesnt explain the causes of poor health.

Body Mass Index Wikipedia
Is body weight a reliable measurement of overall health. Ideal weight this is the range of weight that anyone your age should weigh on average. Staying a healthy weight can be a challenge and knowing what weight is healthy for you can be too. Typically a person is judged to be of normal weight based on body mass index or bmi which measures weight relative to height. Most people rely on the body mass index or bmi which is a measure of our weight in relation. Also a healthy weight varies depending on your age and if you have any health problems says professor john dixon head of clinical obesity research at baker idi heart and diabetes institute. Bmi body mass index which is based on the height and weight of a person is an inaccurate measure of body fat content and does not take into account muscle mass bone density overall body.
However this one size fits all approach may be flawed according to researchers from the university of california los angeles ucla. For example if the results display small it means that the person has a smaller body size for his or her age. Height and weight are the two factors that determine a persons body mass index bmi a measure of body fat and general health. Health is more strongly correlated with body fat percentage and distribution than with overall weight but getting an accurate measure of ones muscle to fat ratio is not especially simpleand. Body frame size this is simply the interpretation of your size on the basis of your weight and height in correspondence with your age. Body fat scales can be an easy way to track your body fat percentage but they may not tell the complete story about your health.
Accuracy can also vary depending on various factors including. Bmi is an inexpensive and easy screening method for weight categoryunderweight healthy weight overweight and obesity. Ranges from 185 to 25. Body mass index bmi is a persons weight in kilograms divided by the square of height in meters.