I would like to know your height , weight and lifestyle. As you are from IT field, its very much obvious that you are into sedentary lifestyle pattern. Get little active - indulge in high pace exercise as running or jogging, skipping, etc this will help you increase BMR and that will urge for eating more. Then you can help yourself by eating more of good amounts of cereals and pulses, milk and milk products, nuts and seeds, fruits and vegetables. In short follow a rainbow diet. This will help your body with all the macro and micro nutrients. But make sure that you don't indulge in unhealthy meal pattern. You can anytime message me personally, I will help you with exact diet plan and minimum activity required for you.
Hi.try to eat skinned out boiled chicken 1-2 pieces twice a week, fish curry not fish fry as it is rich in vitamins, eat fresh raw sprouts everyday twice, include berries and fresh fruits and vegetables like avocado,pears, apples, citrus fruits,papaya,guava,carrots, tomatoes all this things are rich in fibres and vitamins. Your morning diet should include whole egg and a glass of milk, if possible nuts like almond, walnut, peanuts etc try to repeat this in the evening also. Include green leafy vegetables in your diet. Milk products like chesse,panner etc and meat can help you gain weight but since they contribute more towards fat and you need proteins instead of fat to build your body mass try to avoid it. Drink plenty of water and stay hydrated. Do daily brisk walking, cycling for 5-6kms,yoga and meditation.if possible go for a trekking or join some rock climbing classes if such a facility is available in your place and do it on a regular basis which will help you in developing stamina and strength.if you are not satisfied kindly consult a dietician