Hi, Well, gaining weight should be healthy and eating a lot is not a correct way out. So the correct way is to incorporate more proteins in your diet and do a regular workout. Weight gain you will have to maintain proper nutritional supplementation to the body through diet and also start doing muscle or weight training to gain muscle mass. You should eat a blend of carbohydrates, proteins and fats. Add whole grains, rice, potatoes, sweet potatoes, ghee [in limits] and also paneer, tofu, eggs [if not vegetarian] and nuts in the diet. Start weight training sessions under the supervision of a trained Physical Trainer. Take proper sleep and drink plenty of water. You can also be advised protein supplements but take only under the supervision of a dietician and in calculated doses. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Honey Arora, Dentist