Laksa Kedah sits in the same family as Penang asam laksa, sour, fish-based, built on tamarind and boiled mackerel rather than coconut. That makes it one of the lighter laksas, around 400 calories with only about 9g of fat. The protein from the flaked fish is decent and the calorie load is mostly the rice noodles, not oil or coconut.
Heads up, I will be straight with you: there is no official nutrition data for laksa Kedah specifically. This number is a careful estimate based on the asam laksa family, nudged for Kedah's heavier flaked fish. Some stalls add a spoon of santan or sugar, which pushes it 50 to 100 calories higher. Treat it as a guide.