underweight: adult BMI 18.5 or less; child BMI 5th percentile or less
underweight: adult bmi 18.5 or less; child bmi 5th percentile or less
underweight: adult BMI 18.5 or less; child BMI 5th percentile or less
underweight: adult bmi 18.5 or less; child bmi 5th percentile or less