1. What is Body Mass Index (BMI)?

Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. It is widely used in New Zealand health guidelines to screen for weight categories that may lead to health problems.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight_{kg} \) — Weight in kilograms
• \( height_{m} \) — Height in meters

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 Calculation

Details: BMI is an important screening tool in New Zealand healthcare to identify potential weight problems in adults. However, it should be used alongside other assessments as it doesn't directly measure body fat.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What are the BMI categories used in New Zealand?
A: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obese (≥30).

Q2: Is BMI accurate for everyone?
A: BMI may not be accurate for athletes (high muscle mass), elderly (loss of muscle mass), pregnant women, and children.

Q3: What is a healthy BMI range for adults in NZ?
A: A BMI between 18.5 and 24.9 is considered healthy for most adults according to New Zealand health guidelines.

Q4: Should BMI be the only measure of health?
A: No, BMI should be used alongside other measurements like waist circumference, diet assessment, and physical activity levels.

Q5: How often should I check my BMI?
A: For most adults, checking BMI every 6-12 months is sufficient unless you're actively trying to lose or gain weight.