Ayam kapitan is the fancy cousin of regular chicken curry. It is a Nyonya dish, a dry-style curry where the rempah, that thick paste of chili, lemongrass, galangal, candlenut and belacan, is fried down hard in oil before the chicken and coconut milk go in. The result is thick, clingy and intensely flavoured, finished with a squeeze of lime that cuts through the richness. At around 410 calories per serving, it sits in the same ballpark as a good ayam masak, with a solid 28g of protein from the chicken. The carbs stay low at 12g since there is no sugar glaze, but the fat is up at 28g, and that comes from two places: the oil the rempah is fried in, and the coconut milk that thickens it.
The richness is the whole point of this dish, which is also the calorie problem. Because it is a dry curry, the sauce clings to every piece rather than sitting watery at the bottom, so you eat more of the santan and oil per bite than you would with a thin curry. The amount of coconut milk is the big lever, a kapitan made with more santan and a heavier oil fry can climb toward 480, while a lighter hand keeps it nearer 360. Using chicken thigh with skin versus breast also moves it. If you are watching it, the move is the same as any curry: eat the chicken, do not spoon all the thick gravy and oil over your rice, and pair it with veg. The flavour is in the rempah clinging to the meat, you do not need to drink the oil.