bmi overview (for me)

 this is for me (165cm / 5'5)

54kg - 19.8 (normal)

52kg - 19.1 (normal)

51kg - 18.7 (just 700gr underweight)

50kg - 18.4 (1.7kg underweight) 

49kg - 18.0 (2.7kg underweight)

48kg - 17.6 (3.7kg underweight)

46kg - 16.9 (5.7kg underweight)

45kg - 16.5 (6.7kg underweight)