Bone marrow is about 780 calories per 100g, almost entirely fat. A single bulalo bone gives 20 to 25g of marrow, which is 160 to 200 calories that most people slurp out in ten seconds. The shank meat around it is honest beef at 260 calories per 120g with 30g of protein. So a bowl is 520 if you eat the marrow and about 350 if you leave it, which nobody does.
The Tagaytay version is a different animal. Bulalo houses along the ridge sell a bowl for 400 to 600 pesos meant for 2 to 3 people, with two or three bones and 300g of meat. Split in two, each person is at 800 to 1,000 calories of soup, then the rice, then the tawilis. The broth also carries a fat layer from 4 hours of simmering that adds 40 to 80 calories per bowl unless it was skimmed.
Nilagang baka is bulalo without the marrow bone and is the sensible choice at about 400 calories a bowl with the same meat and vegetables. Kansi, the Ilonggo sour cousin, is around 480 because it uses the same bone but the batuan fruit and less corn. Corn on the cob in bulalo is about 45 calories for a 50g chunk, so it is not the issue.