About Body Fat Percentage
Your weight helps track *size*, but your Body Fat Percentage tracks *composition*. Two people can weigh the same but look and feel completely different depending on their ratio of muscle to fat. This tool gives you a window into that ratio without needing expensive scans.
Scientific Basis
This tool uses the U.S. Navy Method (Hodgdon & Beckett, 1984). It estimates body density using circumferences of the waist, neck, and hips (for women) relative to height. It correlates well with hydrostatic weighing, usually within a 3-4% error margin.
Health Implications
High body fat is a stronger predictor of mortality than high BMI.
- Visceral Fat: Fat stored inside the abdomen surrounds vital organs and releases inflammatory markers.
- Hormonal Health: Both very high and very low body fat percentages can disrupt hormone production (testosterone, estrogen).
Actionable Tips
Prioritize Protein: Helps retain muscle while losing fat.
Sleep: Poor sleep increases cortisol, which promotes fat storage.
Compound Lifts: Squats and deadlifts stimulate muscle growth better than isolation exercises.
Limitations
Accuracy depends heavily on measurement precision. It does not account for bone density differences and can be less accurate for extremely lean or extremely obeses individuals.