1. What is BMI?

Body Mass Index (BMI) is a value derived from the mass (weight) and height of a person. It is used to categorize whether a person is underweight, normal weight, overweight, or obese based on tissue mass (muscle, fat, and bone) and height.

2. How Does the Calculator Work?

The calculator uses the BMI formula:

Where:

• \( weight \) — Body weight in kilograms (kg)
• \( height \) — Height in meters (m)

Explanation: BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems more objectively with their patients.

3. Importance of BMI for Weight Loss Surgery

Details: BMI is a key factor in determining eligibility for weight loss surgery. Generally, patients with BMI ≥40, or ≥35 with serious obesity-related health conditions may qualify for bariatric surgery.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For accurate results, measure height without shoes and weight in light clothing.

5. Frequently Asked Questions (FAQ)

Q1: What BMI qualifies for weight loss surgery?
A: Typically BMI ≥40 alone, or ≥35 with comorbidities like diabetes or hypertension. Some programs may consider lower BMIs with severe comorbidities.

Q2: What are the BMI categories?
A: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obese Class I (30-34.9), Obese Class II (35-39.9), Obese Class III (≥40).

Q3: Are there limitations to BMI?
A: BMI doesn't distinguish between muscle and fat. Athletes may have high BMI without excess fat. It may underestimate body fat in older people.

Q4: How often should BMI be checked before surgery?
A: Typically monitored throughout the preoperative evaluation process, which may last several months depending on insurance requirements.

Q5: Does BMI predict surgical risks?
A: Extremely high BMI (>50) may increase surgical risks, but other factors like overall health and comorbidities are also important considerations.