Risks of High BMI

Knowing your BMI can reveal dangers associated with weight.
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People are becoming increasingly aware not only of the dangers of being obese, but also the dangers of being moderately overweight. You might think that extra 15 or 20 pounds you are carrying is harmless. Knowing your body mass index, or BMI, can give you some idea of whether your weight is threatening to good health. Understanding the risks of a high BMI can help you avoid experiencing serious and sometimes irreversible consequences of being overweight.


    Body mass index is a calculation that requires only your height and weight. According to the Centers for Disease Control and Prevention, BMI is a fairly reliable indicator of body fatness for most people. Because it is an easy calculation and does not require extra expense, it is often used by doctors. Though not a diagnostic tool, it is a way for clinicians to screen for weight categories that may potentially lead to health problems.

Risk Categories

    The National Heart Lung and Blood Institute cites disease risks for high BMI ranges. If you have a BMI of 25 to 29.9, you are overweight and have an increased disease risk. For a BMI of 30 to 34.9, you are in obese class I and have a high disease risk. For the obese category with a BMI of 35 to 39.9, you are class II obese and your disease risk is considered to be very high. And for those in the extremely obese range with a BMI of 40 or more, the disease risk is considered to be extremely high. These values are for those with normal waist circumferences; your risk is higher if your waist circumference is greater than the parameters considered to be in a normal range.

Specific Diseases

    The BMICalculator.org website states that being in the overweight category with a BMI of 25 to 29.9 makes you more prone to cardiovascular disease and Type II diabetes. Being in the BMI obese range makes you more prone to certain types of cancer, gallbladder problems, diabetes, cardiovascular disease and high blood pressure. Depression that comes with the social stigma of being obese and the complications this can bring are other risks.


    Although the BMI calculator is a good tool for the majority of the population, it does have limitations. It is not quite as accurate in the case of those with a muscular build. Another consideration is an extremely low BMI, which is not necessarily desirable. BMICalculator.org states that being too thin could lower your body's immunity and make you more prone to infections, osteoporosis and infectious diseases.

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