Ayam bakar is genuinely one of the more diet-friendly things you can pick off a nasi campur counter, which is not something you can say about most Malaysian lauk. At 290 calories for a whole piece of thigh or drumstick, you are getting 28g of protein for that spend. The calories mostly come from the chicken itself with skin (245 cal) and the marinade adds about 45 calories on top. Where things go sideways is the madu version. That honey glaze is not a small difference, it pushes a piece up to 330 calories and bumps your carbs noticeably. Berempah sits in the middle at 300 calories because the rempah paste adds a bit of oil. So the version matters, but none of them are disaster territory lah.
What actually changes the maths is three things: version, skin, and what you eat with it. Biasa saves you 10 to 50 calories versus berempah or madu. Removing the skin before eating knocks off roughly 40 to 60 calories. And the rice underneath is the real wildcard, 200g of white rice is already 260 calories before you even touch the chicken. If you are eating ayam bakar at a warung and wondering why you are not losing weight, the honest answer is probably not the ayam. It is the rice, the sambal, and the kuah that come with it. Keep the chicken, manage the sides.