A BMI less than 18.5 indicates underweight (possibly caused by disease, malnutrition or eating disorders such as anorexia nervosa) and a BMI over 25 as overweight (possibly caused by poor diet choices or lack of exercise).
Likewise, is it good to have a low BMI?
If you have a BMI of: Under 18.5 – you are considered underweight and possibly malnourished. 18.5 to 24.9 – you are within a healthy weight range for young and middle-aged adults. 25.0 to 29.9 – you are considered overweight.
What causes a person to be underweight?
Causes. A person may be underweight due to genetics, metabolism, drug use, lack of food (frequently due to poverty), eating disorder, or illness (both physical and mental). Being underweight is associated with certain medical conditions, including diabetes, hyperthyroidism, cancer, or tuberculosis.