Deficiency of vitamin and minerals generally it happens. Check ur haemoglobin. Contact me through this link prac.to/sabasheikh

Hi We would like to know your complete details such as height,weight etc. Eating healthy is very important. Don't go for unhealthy weight gain as it might create problems in future. For increasing weight you must have to follow a proper diet with high fibre and high protein. Try taking 6 meals in a day. Follow a right meal pattern. Don't skip meals. Consume all fruits and vegetables. Try eating protien rich snacks such as dhokla , besan cheela , sprouts, egg whites during mid morning and evening time. Your diet should be balanced Eat curd/ raita + salad  with lunch Dinner should not be as heavy as lunch. Breakfast is important meal of the day. Learn more about sources of protien , fibre , carbohydrates etc. Some exercise is also important. Regards, Godiets.