What is body mass index

Being underweight could be a sign you're not eating enough or you may be ill. If you're underweight, a GP can help. Find out more in underweight adults. Keep up the good work! For tips on maintaining a healthy weight, check out the food and diet and fitness sections. The best way to lose weight if you're overweight is through a combination of diet and exercise. The BMI calculator will give you a personal calorie allowance to help you achieve a healthy weight safely. The best way to lose weight if you're obese is through a combination of diet and exercise, and, in some cases, medicines.

See a GP for help and advice. Black, Asian and other minority ethnic groups have a higher risk of developing some long-term chronic conditions, such as type 2 diabetes. Measuring your waist is a good way to check you're not carrying too much fat around your stomach, which can raise your risk of heart disease, type 2 diabetes and stroke. As can be seen from the list above, there are numerous negative, in some cases fatal, outcomes that may result from being overweight.

In some cases, being underweight can be a sign of some underlying condition or disease such as anorexia nervosa, which has its own risks. Consult your doctor if you think you or someone you know is underweight, particularly if the reason for being underweight does not seem obvious.

Although BMI is a widely used and useful indicator of healthy body weight, it does have its limitations. BMI is only an estimate that cannot take body composition into account. Due to a wide variety of body types as well as distribution of muscle, bone mass, and fat, BMI should be considered along with other measurements rather than being used as the sole method for determining a person's healthy body weight.

BMI cannot be fully accurate because it is a measure of excess body weight, rather than excess body fat. BMI is further influenced by factors such as age, sex, ethnicity, muscle mass, and body fat, and activity level, among others.

As well as measuring your BMI, healthcare professionals may take other factors into account when assessing if you're a healthy weight. Muscle is much denser than fat, so very muscular people, such as heavyweight boxers, weight trainers and athletes, may be a healthy weight even though their BMI is classed as obese. Your ethnic group can also affect your risk of some health conditions. For example, adults of South Asian origin may have a higher risk of some health problems, such as diabetes, with a BMI of 23, which is usually considered healthy.

You should not use BMI as a measure if you're pregnant. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet , , pp. Epub Aug Inflammation- sensitive plasma proteins are associated with future weight gain. Aug ; 52 08 : Oxidative stress in obesity: a critical component in human diseases.

International Journal of Molecular Sciences. Dec ; 16 1 Skip directly to site content Skip directly to page options Skip directly to A-Z link. Healthy Weight, Nutrition, and Physical Activity. Section Navigation. Facebook Twitter LinkedIn Syndicate.

About Adult BMI. Minus Related Pages. On This Page. How is BMI used? Why is BMI used to measure overweight and obesity? What are other ways to assess excess body fatness besides BMI? How is BMI calculated?

How is BMI interpreted for adults? Is BMI interpreted the same way for children and teens as it is for adults?