Brief Answer:
eat healthy; provide your height for BMI calculation

Detailed Answer:
Hi,
Thank you for posting your query in healthcaremagic.com
This is Dr. Swarnava dattagupta answering your query.

I understand your concern.
First of all, some people are obese no matter how less they eat and some are lean and underweight no matter how much they eat. This is because of the inherent metabolism one has from birth. So if you are underweight since childhood, then it is difficult for you to gain much weight. You have not provided your height so your BMI or body mass index could not be calculated and your ideal weight in this age could not be determined. Kindly provide your height.
In general, for people asking for weight increase, I advice healthy diet with less fat and junk, more vegetables, protein and carbohydrates. Also having lots of water helps. You can have heavy meals twice daily with small frequent meals in between. But alongwith, adequate exercise is required to keep you fit and your metabolism active. Avoid alcohol and smoking.
You can also consult a dietitian and he/she can prepare you a diet chart which you can follow.

Hope i have answered your question.
If you have any further questions i will be happy to help.
Regards

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