To gain weight it is not about eating too much, but eat high energy and protein dense food frequently in small portions.
1 start eating high energy high protein food. Like almond, ground nut, dry coconut, cashew nut, milk and milk products etc
2 do not take stress
, if you are suffering from any kind of stress do yoga and meditation
3 quite smoking
or any kind of tobacco.
4 eat food which is less in fiber so it can be digested easily and make you hungry again.
5 instead of eating large quantities of food in single meal take small portions of food frequently