This is the dish to order when everyone else is ordering samgyeopsal. Bulgogi uses sirloin or chuck sliced paper thin, so 200g of cooked meat is 330 calories, roughly half of what the same weight of pork belly costs you. The 34g of protein per serving is real, not marketing.
The marinade is where the sugar hides. A typical bulgogi sauce is soy, sugar, grated pear, garlic and sesame oil, and 30g of it per serving adds about 55 calories and 10g of sugar. Ttukbaegi bulgogi, the brothy version served bubbling in a stone bowl with glass noodles, comes in at 320 to 380 calories per serving with the noodles included.
The catch is that bulgogi is almost always eaten with rice, and the sweet juices make rice go fast. One bowl of rice is 300 calories. Two bowls, which the sauce practically demands, turns a 330 calorie dish into a 930 calorie meal. A bulgogi lunch set at 10,000 to 13,000 won typically lands at about 700 with rice and side dishes.