Step on a scale, calculate a number, and suddenly a single figure is supposed to summarize your health. It sounds too simple — because it is. Body Mass Index, or BMI, has been the go-to metric in medicine and public health for decades, but it has a growing number of critics, and for good reason. If you have ever been told you are in a “healthy” weight range while feeling far from healthy — or labeled “overweight” while being physically fit — this blog is for you. At Express Internal Medicine in Plano, TX, Dr. Iram Qureshi, DO, takes a broader view when assessing a patient’s overall health.
What Is BMI and How Is It Calculated?
BMI is a simple calculation: your weight in kilograms divided by the square of your height in meters. The resulting number places you in one of four categories — underweight (below 18.5), normal weight (18.5-24.9), overweight (25-29.9), or obese (30 and above).
The appeal of BMI is its simplicity. It requires no equipment, just a scale and a measuring tape. That practicality made it popular in population-level health research during the mid-20th century, but using it as a precise individual health assessment tool has always been its weakness.
Why BMI Is Misleading
The core problem with BMI is that it measures mass, not composition. It cannot distinguish between muscle and fat, bone density, fluid retention, or where fat is distributed on the body. This creates some well-documented absurdities:
- A highly muscular athlete with very low body fat may be classified as “overweight” or even “obese” by BMI
- An individual with a “normal” BMI may still carry a high percentage of body fat — sometimes called “skinny fat” or normal weight obesity
- BMI does not account for sex differences, even though women typically carry more body fat than men at the same BMI
- It does not adjust meaningfully for age, though body composition naturally shifts over time
- Studies have noted that BMI cutoffs may not apply equally across different ethnicities, with some populations facing greater health risks at lower BMI values
What Is Body Composition?
Body composition refers to the proportion of fat mass versus lean mass (muscle, bone, water, and organs) in your body. Unlike BMI, it offers a much more nuanced view of what your body is actually made of.
Key metrics in body composition assessment include:
Body Fat Percentage: The percentage of your total weight that comes from fat tissue. Healthy ranges differ by sex and age.
Lean Body Mass: The weight of everything in your body except fat — including muscle, bone, organs, and water.
Visceral Fat: Fat stored around internal organs in the abdominal area. High visceral fat is more strongly linked to cardiovascular disease and type 2 diabetes than overall body fat.
Muscle Mass: Muscle is metabolically active tissue. Higher muscle mass is associated with better blood sugar regulation, stronger bones, and a higher resting metabolism.
Better Alternatives to BMI
Several measurements can offer more useful clinical information alongside or instead of BMI:
- Waist circumference — a measure of abdominal fat and a useful predictor of metabolic risk
- Waist-to-height ratio — some researchers consider this a stronger predictor of cardiovascular risk than BMI
- DEXA scan — the gold standard for body composition analysis, measuring bone density, fat, and lean mass
- Bioelectrical impedance — less precise than DEXA but more accessible, used in many clinical and home settings
- Waist-to-hip ratio — helpful for understanding fat distribution patterns
Should BMI Be Abandoned?
Not necessarily. BMI remains a useful screening tool at the population level and in settings where more sophisticated measurements are not available. But it should be treated as one data point among many — not a verdict on someone’s health. Major medical organizations, including the American Medical Association, have called for BMI to be used in conjunction with other metrics rather than in isolation.
Dr. Iram Qureshi, DO, evaluates patients based on a full clinical picture, not just a single number. If you have concerns about your weight, metabolic health, or body composition, a comprehensive evaluation can give you far more useful information than a BMI calculation alone.
Frequently Asked Questions
Is a normal BMI always healthy?
Not necessarily. Someone with a normal BMI can still have high body fat, low muscle mass, or metabolic risk factors. BMI alone does not confirm good health.
Can you have obesity-related health risks with a normal BMI?
Yes — this is sometimes called “metabolically obese, normal weight.” Blood pressure, blood sugar, and cholesterol levels provide additional context beyond BMI.
What is a healthy body fat percentage?
General guidelines suggest 10-20% for men and 18-28% for women as healthy ranges, but these vary based on age and individual health goals.
Is BMI accurate for athletes?
BMI is generally not an accurate health indicator for athletes, as their higher muscle mass often pushes BMI into “overweight” or “obese” ranges despite low body fat.
Can I measure body composition at home?
Bioelectrical impedance scales offer at-home body composition estimates, though accuracy varies. Your doctor or a clinical setting can provide more reliable measurements.
Medical Disclaimer: This blog post is intended for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making any changes to your health regimen. If you have questions about your health, please speak with Dr. Iram Qureshi, DO, or another licensed medical professional.
Dr. Iram Qureshi is a dedicated board-certified Internal Medicine physician with a strong passion for preventative care and weight-loss management. With over five years of experience as a hospitalist, Dr. Qureshi has honed her expertise in treating acute medical conditions and focusing on preventing hospitalizations. She is committed to providing compassionate care and evidence-based guidance to help patients lead healthier lifestyles.
As the co-founder of Express Internal Medicine, Dr. Qureshi works alongside her husband, Dr. Adeel Khan, to create a welcoming and supportive environment for patients. She specializes in weight-loss management, offering personalized treatment plans aimed at achieving sustainable health outcomes. Dr. Qureshi holds degrees from Ohio State University and The University of Pikeville-Kentucky College of Osteopathic Medicine, with internal medicine training from Midwestern University OPTI in Sierra Vista, Arizona.
Fluent in English and Urdu/Hindi, Dr. Qureshi is passionate about educating her patients and empowering them to take charge of their health. Outside of her medical practice, she enjoys cooking, traveling, photography, and movies.
