Hello Sir:
You ask many questions but more information is needed to provide any type of informed answer. First of all, you ask about diet -please tell me what would you like to know? I have been in the field 30 years and never stop learning, so you are asking a broad question. Clarify, didn't digest properly how? Your stools, your stomach, what? So, to try to intuitively address your concerns, Sheenam, you are looking to put on about 30 pounds. For every pound you want to put on, it will take an extra 500 calories per day. So, considering that you are eating approximately 1700 calories per day to maintain you weight without entering exercise into the equation. You should be eating a total of 2700 kcals per day to gain 2 pounds. Now, muscle weighs more than fat so if you do strength training that will help proportion your weight gain. Cardiovascular exercise is also encouraged if your doctor has no restrictions on you. If your foods are not digesting well you need to look at timing, amount, type (i.e. are you lactose intolerant with milk making you bloat,etc), adding fiber when you aren't used to it - there could be a host of reasons. Keep a food diary so if you decide to seek further nutritional consultation you will have more information to provide., There is more guidance that can be given about how to eat when exercise is an issue. .To gain weight include healthy high fat foods frequently like olives, olive oil, nuts, nut butter, avocados, dark chocolate (high in antioxidants), raisens,dates I sincerely hope I helped somewhat. Kathy Shattler, MS,RDN