Australian BMI Categories (Department of Health)
| BMI Range | Category | Health Risk |
|---|---|---|
| Below 18.5 | Underweight | Increased — malnutrition, osteoporosis, immune dysfunction |
| 18.5 – 24.9 | Healthy Weight | Lowest overall health risk range |
| 25.0 – 29.9 | Overweight | Increased — cardiovascular disease, type 2 diabetes |
| 30.0 – 34.9 | Obese Class I | Moderate increased risk |
| 35.0 – 39.9 | Obese Class II | Severe increased risk |
| 40.0 and above | Obese Class III | Very severe increased risk |
Waist Circumference — A Critical Additional Measure
Australian health authorities strongly recommend measuring waist circumference alongside BMI, as abdominal fat distribution is independently associated with metabolic disease risk. A person within a healthy BMI range but with a large waist circumference still carries elevated cardiovascular and metabolic risk.
- Men: ≥94cm = increased risk; ≥102cm = substantially increased risk
- Women: ≥80cm = increased risk; ≥88cm = substantially increased risk
BMI for Different Australian Populations
Standard BMI categories were developed primarily from European population data. Research suggests that people of Asian background may have increased health risks at lower BMI values. Some Australian health professionals recommend lower thresholds for Asian Australians: overweight at BMI ≥23, obese at ≥27.5. Discuss with your GP if this may apply to you.
Australian Physical Activity Guidelines
The Australian Department of Health recommends adults aged 18–64 complete at least 150–300 minutes of moderate intensity physical activity per week (or 75–150 minutes of vigorous activity), plus muscle-strengthening activities on at least 2 days per week. Meeting these guidelines is associated with significantly reduced chronic disease risk independent of BMI.