Therefore, BMI should not be used as a guide for adults who are very short (less than 150 cm) or very tall (more than 190 cm). Height – BMI is not totally independent of height and it tends to overestimate obesity among shorter people and underestimate it among taller people.In these instances, it is important to consult a dietitian who will provide helpful advice. Their BMI may be slightly lower, but this does not necessarily mean they are underweight. Physical disabilities – people who have a physical disability and are unable to walk may have muscle wasting.Muscles – body builders and people who have a lot of muscle bulk will have a high BMI, but are not overweight.This means there are some exceptions to the BMI guidelines: However, BMI cannot differentiate between body fat and muscle mass. Generally speaking, the more body fat you’re carrying, the higher your health risk.
Why isn’t BMI always the best measure of health? people with a physical disability, who are unable to walk and may have muscle wasting.īMI is also not an accurate indicator for people with:.BMI isn’t always the best measure of healthĪt the population level, BMI is used to indicate level of risk for morbidity (disease risk) and mortality (death rates).ĭifferences in BMI between individual adults of the same age and sex are usually due to body fat, however there are many exceptions to this rule, which is why a BMI figure may not always be accurate.īMI calculations will overestimate the amount of body fat for:īMI calculations will underestimate the amount of body fat for: Some researchers have suggested that a BMI range of 22–26 kg/m 2 is desirable for older Australians. over 30kg/m 2 – you are considered obese.įor older Australians over the age of 70 years, general health status may be more important than being mildly overweight.25.0 to 29.9kg/m 2 – you are considered overweight.18.5 to 24.9kg/m 2 – you are within a healthy weight range for young and middle-aged adults.under 18.5kg/m 2 – you are considered underweight and possibly malnourished.Your BMI will classify you as ‘underweight’, ‘healthy weight’, ‘overweight’ or ‘obese’, as defined by the World Health Organization. You can use the body mass index (BMI) calculator for adults to calculate your BMI, provided you know your: However, in adults who have stopped growing, an increase in BMI is usually caused by an increase in body fat.
This makes it difficult to have set values for BMI cut-offs for young people. It is calculated by dividing your weight in kilograms by your height in metres squared (m 2).īMI is intended for adults only, as children and adolescents are constantly growing. Body mass index (BMI)īody mass index (BMI) is an approximate measure of your best weight for health. Abdominal obesity is measured using waist circumference. Increased abdominal obesity is related to a higher risk of cardiovascular disease, type 2 diabetes and cancer. For this reason, your waist circumference is thought to be a better predictor of health risk than your BMI. However, the distribution of fat on your body is more important that the amount, when assessing your disease risk. A much cheaper alternative is to estimate your total amount of body fat by calculating your body mass index (BMI).īMI is a useful indicator of health at the population level. The amount of fat your body has stored can be accurately measured with a dual-energy absorptiometry (or DXA) machine.
However, too much or too little body fat can increase your risk of illness and disease, depending on where your body stores it. It is normal for your body to store energy as fat.