Start workout and you can have isolated whey protein after your workout that would help you..Increase your calories intake...balancing your macros and micros..if you take morning and evening tea replace it with banana shake adding some nuts to it,add milk to your diet,add whole grain food avoid eating refined foods, add lentils and legumes to your diet,add more of fruits and vegetables to your diet..avoid fried food, avoid soda drinks..replace white rice to brown rice..add eggs to your diet