Pork udon (niku-udon) is a spin on a very traditional Japanese dish, udon, originating from the Edo era. As soon as milling became mechanized, udon dish became one of the easy and widely popular dishes - rice noodles boiled in water and topped with one of the local sauces make for a quick and easy meal.
Niku-udon are barely any more complex than basic udon recipe. All you have to do is add chunks of pork-loin to the mix and you have yourself Japanese meaty udon dish. A low-calorie and high-energy meal may sound like a dream, but rice noodles are very high in carb values, and even if you use lean pork bits, you will still get quite an amount of fat in the dish: so it's not a meal for every day, but if you need lots of energy and sodium, this is the dish to turn to. Just make sure you exercise, or the extra carbs will quickly show if you make this meal a part of your regular dietary plan.