Siu yuk is pork belly with the skin blistered. A 130g portion on rice is about 500 calories before you count the rice, because belly is roughly a third fat by weight. CFS measured 12g of saturated fat in a plate of roast pork rice, more than the 10g the WHO considers a reasonable daily ceiling. Char siu is leaner meat but it is glazed in maltose and the fatty 半肥瘦 cut is what most shops chop by default, which is why it comes out slightly higher at 1,000.
The rice is the quiet half of the plate. Most siu mei shops put 280 to 300g of cooked rice under the meat, which is about 360 calories and more than the meat's carb-free 500. Then the shop spoons roast juices and sweet sauce over it, another 30 to 50. Ask for less rice (少飯) and the plate drops by around 120 calories with the same amount of meat, which is the cheapest calorie cut in Hong Kong.
Soy sauce chicken is the one to know about. The CFS figure for 油雞飯 is 770 calories versus 930 for roast pork, a 160 calorie gap for the same plate size. Peel the skin and it is closer to 650. The double combo (雙拼) plates that stack char siu and roast pork are 1,100 or more, and the roast goose leg on rice with skin can pass 1,000 on its own. Pick one meat, pick it lean, and this is a decent 30g plus protein lunch.