When most people think about health and weight loss, the first numbers that come up are weight and BMI. These are simple to measure and easy to compare, but they don’t always tell the full story. At Inspire Bariatrics, we want you to understand what these numbers mean—and what they don’t.
What Is BMI?
BMI (Body Mass Index) is a formula that compares your weight to your height. It’s calculated by dividing your weight in kilograms by your height in meters squared.
BMI categories are:
- Underweight: less than 18.5
- Healthy weight: 18.5 – 24.9
- Overweight: 25 – 29.9
- Obesity class I: 30 – 34.9
- Obesity class II: 35 – 39.9
- Obesity class III: 40 or more
The problem: BMI doesn’t take into account things like muscle mass, bone structure, or body composition. A muscular athlete may be labeled “overweight” while someone with low muscle but more body fat might fall in the “healthy” range.
Why Weight Alone Isn’t Enough
Weight is an easy number to track, but it doesn’t tell us what kind of weight you’re losing. Losing too much muscle—a problem known as sarcopenia—can harm your health long-term. Muscle helps keep you strong, supports independence as you age, and lowers your risk for conditions like diabetes, heart disease, and even dementia. That’s why our goal isn’t just for you to lose weight, but to lose fat while maintaining lean body mass.
Why the Medical Community Still Uses BMI
For decades, the medical community has used BMI to decide who qualifies for bariatric surgery.
- Old guidelines (1991 NIH Consensus): Surgery was recommended for BMI ≥40, or BMI ≥35 with serious health conditions.
- Updated guidelines (2022 ASMBS/IFSO): Surgery is now recommended for BMI ≥35 regardless of health problems, and even for BMI 30–34.9 if metabolic disease like diabetes is present.
- Race-specific notes: Some studies and recommendations recognize that risks may occur at lower BMI thresholds in certain Asian populations. This has led to slightly different cutoffs for surgical consideration in those groups.
Insurance companies don’t all move at the same pace. Many still use the older guidelines, though some—like Cigna and UnitedHealthcare—are beginning to cover patients under the updated recommendations.
Final Thoughts
At Inspire Bariatrics, we follow the latest recommendations, not outdated benchmarks. If your doctor or insurance has told you that your BMI isn’t “high enough,” it may be time to re-evaluate.
- We’re here to help you:
Review your insurance criteria. - Explore self-pay or financing options if needed.
- Focus on preserving your health—not just chasing a number on the scale.