It is important for you to know that you need not merely change your diet in order to gain weight. You will also have to follow a regular routine of exercise to the same end. Exercise is not only a great way to develop muscle mass, which will lead to weight gain, it is also an excellent hunger stimulator. If you exercise, you will automatically feel hungry and your diet will improve considerably. So, the first thing you must do is add about 45 minutes of exercise at least thrice a week to your routine. If possible, try to exercise everyday. The best form of exercise that stimulates hunger as well as build muscle mass and adds weight is swimming. If you can, try to get in a swim everyday. This will tone your body considerably. It will also make you extremely hungry!
You must try to eat at least five times a day. This is healthier than eating fewer times. Even if you eat small meals, it is better to eat more frequently. This will automatically increase the quantities of food going in. Add whole milk to your diet. Try to have at least two glasses of whole milk everyday. This will help you not only to gain weight, it will also add to your musculature. You should also start adding simple carbohydrates such as potatoes, white bread, regular pasta and rice to your daily diet. Carbohydrates are the fastest and easiest way to gain weight. Since you are vegetarian, meat is completely out of question for you. Instead, you can add nuts and dry fruits to your diet. Cashews, in particular are extremely rich in protein as well as fat. You should have at least a fistful of a mixture of cashews, almonds, pistachios, raisins and any other nuts. This can actually be a snack for any one snack time. Dry fruits are also extremely healthy and will add to your weight as well as your general good health. All milk products are also important to move towards achieving your goal. Try to eat cheese and whole milk full fat yogurt with your meals. All of these steps will help you to gain weight and will also add to your musculature. Do keep in mind that if you take all of these steps slowly, you will be able to see positive results within a couple of month. You would need to be patient and not give up your efforts in the meantime.
answered by S C