Empurau is basically the wagyu of freshwater fish. It's expensive (think hundreds of ringgit per kilo at a restaurant), it's caught wild in Sarawak's rivers, and it's eaten simply steamed so nothing masks the natural fat. That fat is what gives it the flavour and that's also what drives the 530 calories per serving. At 65g protein and 25g fat, this is a high-protein, moderate-fat meal with almost zero carbs. For a weight loss meal it's actually not bad in terms of macros, assuming you skip the white rice and eat just the fish. Heads up though: these numbers are a genuine ballpark estimate. Hard nutritional data on Empurau is basically non-existent, so treat 530 cal as a reasonable guess rather than a lab result.
What actually changes the maths here is the sesame oil drizzle and any extra soy-based sauces the kitchen adds. That 5g sesame oil accounts for about 40 calories on its own, and some restaurants are heavy-handed with it. Ask them to go light. The bigger variable is portion size, because sharing a whole fish at a table means your 300g of edible flesh can swing 50 to 80 calories either way depending on who takes the thick belly cuts versus the thinner tail sections. Belly meat = more fat = more calories. If you're watching closely, take the tail and leave the belly to the person who's not counting lah.