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Published on: 7/21/2026
How is BMI used to determine if someone is overweight?
What Is BMI and What Does "Overweight" Mean?
Body Mass Index (BMI) is a screening number calculated from your height and weight to estimate whether your body weight falls within a healthy range. Health professionals use BMI as a quick indicator of potential weight-related health risks.
BMI Categories at a Glance:
- Underweight: Below 18.5
- Healthy weight: 18.5 – 24.9
- Overweight: 25.0 – 29.9
- Obese: 30.0 and above
A BMI between 25 and 29.9 places a person in the overweight category, which may be linked to increased risk of conditions like high blood pressure, type 2 diabetes, and heart disease.
However, BMI alone doesn't tell the whole story. Factors like muscle mass, age, sex, and body composition matter too. If you're noticing symptoms alongside weight changes — such as fatigue, joint pain, shortness of breath, or shifts in appetite — those clues could point to something more specific worth understanding. Rather than guessing, take a few minutes to run a free, instant, online symptom check to see what your body may be telling you and get clear, personalized guidance on your next steps.
Reviewed for medical accuracy: 07/20/2026
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Body Mass Index (BMI) is a simple way to find out if someone is overweight by using their height and weight. It is a number that helps doctors and researchers categorize people based on their weight compared to their height.
How BMI is Calculated: To find BMI, you take a person's weight in kilograms and divide it by their height in meters squared.
Categories: According to the studies, a BMI of 25 to 29.9 means a person is overweight. A BMI of 30 or more means they are considered obese.
Why It's Used: BMI is widely used because it's easy to calculate and doesn't require expensive equipment. However, it doesn't always perfectly measure body fat or health. Some people may have a high BMI because they have a lot of muscle, not because they have too much fat.
Using BMI helps doctors and researchers keep track of weight problems in the population, which can help in planning health programs and understanding health risks related to weight. If you're concerned about symptoms related to your weight or overall health, you can use a free symptom checker to better understand what might be affecting you.
(References)
Klatsky AL, Zhang J, Udaltsova N, Li Y, & Tran HN. (2017). Body Mass Index and Mortality in a Very Large Cohort. The Permanente journal, 28678695.
Flegal KM, Kit BK, & Graubard BI. (2014). Body mass index categories in observational studies .... American journal of epidemiology, 24893710.
Karchynskaya V, Kopcakova J, Klein D, Gába A, Madarasova-Geckova A, van Dijk JP, et al. (2020). Is BMI a Valid Indicator of Overweight and Obesity for .... International journal of environmental research and public health, 32635439.
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