Is there a way I can use the If-Else statement to run this code correctly

Newbie here! I am trying to use the if-else statement to compare a BMI result against the standard BMI threshold. so I tried to create variables that represented the threshold hold for underweight, healthy, overweight and obese. my BMI result is 28.28639. here the code I ran initially:

BMI<-28.28639

underweight<- 10-18.4

healthy<- 18.5-24.9

overweight= 25.0-29.9

obese= 30.0-50.0

if(10<BMI<18.5){print("underweight")}