People think of bun dau as a light tofu lunch. It is 700 calories for one person, and the tofu is the problem, not the pork. Deep fried tofu absorbs oil: 90g of fried dau comes out at around 210 calories, more than the 50g of boiled pork belly at 120. The cha com, a pork sausage mixed with young green rice and then fried, is 110 for two pieces. The pressed bun is 220 for 200g.
The mam tom bowl is 30 to 40 calories, which is nothing, but it is mixed with a spoon of the hot oil from the tofu pan to make it foam. That is what you are tasting. Some quan add a full tablespoon, 90 calories, and if you dip every piece of tofu and bun you get all of it. The herbs, cucumber and perilla on the tray are the only free part.
The real order at most Hanoi quan is the met day du, the full tray, for two people to share. It adds lòng (boiled intestine), dồi (blood sausage), cha quay (fried pork) and sometimes a fried nem. Split in two, each person eats 900 to 1,000 calories. The quan will also refill the tofu without asking if the tray looks empty. Each refill of three cubes is about 100.