Hello Laksmish, Gaining weight requires a lot of patience. You should exercise regularly to help your metabolism work perfectly. Yoga and meditation should be the next priority of your life. Stressful life, anxieties and tensions are some of the reasons why people do not gain weight. Try to be physically and mentally happy. Happiness adds laughter, activity in life and good blood circulation which is an important factor that aids weight gain. You should have a Master health check up to rule out any disease which has not been diagnosed. You should take vitamin and dietary supplements to stay energetic. You should plan a menu which is nutritious, high in calorie and has a lot of butter content too. Do add a lot of fresh fruits and veggies to your diet. Brown rice, whole wheat and starchy food should be included regularly in your diet if you want a faster gain. Fruits like bananas, avocados, sweet potatoes, pears, etc will be helpful for you. Nuts, legumes, cereals, eggs, red meat, fishes for omega 3 fatty acids, yoghurt, dairy products, peanut butter, smoothies, protein powder, burgars, pizzas, fries, candies and chocolates will help you gain weight. You should increase your diet. Try to eat more than you expend. Eat three or four times in a day. Compounding helps gain weight faster. Drink your favourite beverages any time and anywhere you like. Have a nice day, enjoy good health.