To them, their weight may be important. But they actually don't know if their underweight, healthy or overweight. They think being the the 40's area is safe for them but most of the time, it's underweight.

I've only calculated EXO and Girls' Generation's BMI (BMI stands for Body Mass Index)

EXO's BMI

Suho - Height: 173cm / 5'7" ft. Weight: 52kg / 115lbs - Underweight
Baekhyun - Height: 174cm / 5'7" ft. Weight: 53kg / 117lbs - Underweight
Chanyeol - Height: 185cm / 6'1" ft. Weight: 71kg / 157lbs - Healthy Weight
D.O - Height: 173cm / 5'7" ft. Weight: 51kg / 112lbs - Underweight
Kai - Height: 182cm / 6'0" ft. Weight: 69kg / 152lbs - Healthy Weight
Sehun - Height: 181cm / 5'9" ft. Weight: 53kg / 117lbs - Underweight
Kris - Height: 187cm / 6'1" ft. Weight: 72kg / 157lbs - Healthy Weight
Tao - Height: 183cm / 6'0" ft. Weight: 68kg / 150lbs - Healthy Weight
Luhan - Height: 178cm / 5'8" ft. Weight: 52kg / 115lbs - Underweight
Xiumin - Height: 173cm / 5'7" ft. Weight: 51kg / 112lbs - Underweight
Lay - Height: 177cm / 5'8" ft. Weight: 60kg / 132lbs - Healthy Weight
Chen - Height: 173cm / 5'7" ft. Weight: 63kg / 139lbs - Healthy Weight

Girls' Generation's BMI

Taeyeon - Height: 160cm. Weight: 44kg - Underweight
Jessica - Height: 163cm. Weight: 45kg - Underweight
Tiffany - Height: 163cm. Weight: 50kg - Healthy Weight
Yoona - Height: 166cm or 168cm. Weight: 47kg - Underweight
Sooyoung - Height: 170cm. Weight: 48kg - Underweight
Seohyun - Height: 168cm. Weight: 48kg - Underweight
Hyoyeon - Height: 158cm. Weight: 48kg - Healthy Weight
Yuri - Height: 167cm. Weight: 45kg - Underweight
Sunny - Height: 158cm. Weight: 41kg - Underweight

All I want is for them to not care about their weight but their health. Being underweight is not a good thing. If you want to find out if your underweight, healthy or overweight click here. (And if your from somewhere that uses ft or lbs click on the imperial to change it).