Underweight

People that underweight is always hardest to gain weight compared to people that overweight with their purpose of losing weight.

Why underweight? It is probably due to genetic issue, diet habits or some other health conditions problem.

How to define underweight?

• BMI : below 20.
• Very weak immune system.
• Very skinny type (almost all bones)
• Able to eat a lots but still unable to gain weight.

Any of your friends are under this category?Please let me know, I can help them.