Mee rebus is yellow noodles drowned in a thick, sweet, savoury gravy made from sweet potato, taucu and dried shrimp, topped with a boiled egg, tofu, green chilli and lime. The gravy is the catch. It is not a free clear broth, it is starchy, a bit sweet and carries oil, so it acts as a calorie multiplier on top of the noodles. A plate is around 500 calories.
The egg and tofu give you a little protein but this is mostly a carb and gravy dish. Johor style portions run heavy. It is fine occasionally, just do not assume noodles in soup means light, because this soup is doing work.