So 700 calories for one plate, that is not shocking but it is also not cheap. The villain here is not the gravy or even the seafood, it is those fried kuey teow noodles. When you deep-fry flat rice noodles they soak oil like a sponge, and at 520 calories just from the noodle portion alone, the maths are already stacked before the gravy hits. The egg starch gravy adds another 60 cal, and the mixed seafood at 95 cal is honestly the best value thing on the plate protein-wise. So you get 28g protein for 700 cal, which is decent but not remarkable. This dish suits someone who can fit a 700 cal lunch into their day without going crazy at dinner lah.
Now the honest bit: these numbers are a ballpark estimate because solid nutritional data for Kuey Teow Kung Fu specifically is basically nonexistent, so treat the 700 cal figure as a reasonable educated guess rather than a certified lab reading. What actually swings the number is how aggressively the hawker fries the noodles and how thick they pour the gravy. A stingier uncle with a lighter hand on the oil could realistically drop this to 620 to 650 cal. A generous uncle who double-fries for crispiness and pours a mountain of gravy could push it past 750 easily. If you skip the seafood and go vegetable-only gravy, you save about 100 cal and land at 600. Add pork or chicken to the gravy and you are up at 780. The biggest single lever you have is just asking for less noodles, bro, because 210g of fried kuey teow is honestly a lot.