human
I've heard that a flat stomach is a sign of good health. Is this true?
assistant
Yes, it's true that a flat stomach is associated with good health and fitness. It can be an indicator of overall health as well as a predictor of long-term health outcomes. A healthy body mass index (BMI) score is considered to be between 18.5 and 24.9. A BMI below 18.5 is classified as underweight while one above 25 is overweight or obese.