Oyakodon is the donburi to pick when you want to stay on plan. It is 631 calories, nearly the same as a gyudon, but with 30g of protein instead of 20 and 16g of fat instead of 24. Nothing in it is fried. The chicken thigh is about 70g, the eggs are one and a half, and the rest is rice and a sweet dashi sauce. At Nakau or a soba shop it costs 500 to 700 yen.
The rice is still 60 percent of the bowl. At 250g and 390 calories, the rice outweighs the chicken and egg combined. Ordering 'gohan sukuname' or eating half the rice takes the bowl down to 430 to 500 calories with the same protein, which is a very good lunch. The egg and chicken on top are only about 230 calories together.
Home versions and restaurant versions differ mostly in sugar. A restaurant warishita has sugar and mirin, about 30 calories per serving. Some shops also finish with a third egg yolk on top for richness, another 55 calories. Neither is a big deal. The bigger jump is the 'omori' rice, which adds about 150 calories, and the pickles and miso soup set, which adds about 50.