Healthy Weight Gain Strategies for 18-Year-Olds: Expert Advice

Question
hey this is aman.I am thin.I want to Gain weight.My age is 18 years. Height 168 cm. weight 48. Is it normal?
one of my friend suggested me to have lemon juice + honey + cold water.She said it will increase weight. No she is not a docter she told me that she incresaed weight by drinking that thing.
i searched in google there i found that it was a way of loosing weight but you have to drink with warm water. which one is correct? i am confused. and i cant afford loosing weight anymore. i am thin from the childhood .
please give me some advice to gain weight .
i am sitting at home doing nothing for atleast 2 months.it is a good chance to gain weight.
Thanku.

Answer
The question should be ''how to gain healthy weight''... anyone can gain weight, but gaining fat weight is very unhealthy.  It is really simple actually.... eat plenty of protein in your diet to build muscle mass and avoid getting ''fat'', and perform DAILY exercise, both aerobic and more importantly for you resistance (weights) training.  Building muscle mass with increase your weight in a very healthy way and add good mass to your frame.  So eat right and do resistance or weight training exercise several times a week.  Drinking lemon juice and honey or warm water is not the answer.

JP