Hi, for low weight you need to first know that there are no other problems like digestion issues or malabsorption or hormonal imbalances are there or not. If all ok,then do have filling but nutritious meals at regular small gaps throughout the day.
Next Steps
Follow these -
Have a heavy dinner filled with cereals and protein foods like dal, chana, rajma, egg, fish or lean meat.
Have fruit custard n milk shakes and smoothies.
Have banana milk shakes daily,fruits lile dates n mixed nuts.
Exercises for strength n stamina building.
Stress less.
Sleep well.
Be happy.
Health Tips
For customized diet plan you can consult any of us personally.