The Negative Connotation of Underweight

Underweight, which is the opposite of overweight, is not necessarily more neutral or more neutral than thin. It definitely has a negative connotation, yes, but it's the best one to use if you want to be as neutral as possible and scientific or clinical. I would expect a doctor to say, listen, I think you have to change your diet, eat more protein, maybe eat more times during the day because you are a little underweight. But particularly if you're a tall person, tall people quite often look thin, but medically, they might not be underweight.