Underweight:
Underweight is a term describing a human whose body weight is considered too low to be healthy.
en.wikipedia.org
体重不足:
体重不足指一個人的體重低於健康水平，通常以身高體重指數（BMI）作指標，BMI值低於18.5屬於体重不足。
zh.wikipedia.org
This article uses material from the Wikipedia articles %@, which are released under the Creative Commons Attribution-Share-Alike License 3.0.
Underweight体重不足