430 calories for kari kepala ikan is not terrible for a proper lauk, but the number can creep up fast and here is why: about 185 of those calories come entirely from the coconut milk gravy. The fish head meat itself (jaw, cheek, collar) only accounts for roughly 155 kcal and gives you around 23g of protein, which is decent value considering how much bone, cartilage, and collagen you are working around. Fish head is not the same as fillet, so the edible lean meat yield is lower than you might expect. The okra, tomato, and eggplant are basically free at 35 kcal. So the math is not the fish, it is the gravy you are drowning everything in. For someone trying to lose weight, 430 kcal as your lauk is fine if you pair it with plain rice and keep the rest of the meal boring. Fair warning though: these numbers are a ballpark estimate because there is almost no hard nutrition data for kari kepala ikan. The fat content varies a lot depending on how generous the cook is with coconut milk, so treat 430 kcal as the middle of a 350 to 550 range.
The biggest variable is how much gravy ends up on your plate. At a mamak or curry house, a single portion can swing 80 to 100 calories up or down just based on whether you scoop light or let it flood your rice. If you are sharing a claypot between four people at a banana-leaf meal, your per-person share drops to around 350 calories because you get less fish and more gravy. Opposite direction: if you order your own full portion and pour gravy on your rice like a normal person, you are closer to the 690 kcal range with rice included. The fish head meat itself is lean and reasonably high in protein, so the actual flesh is not the enemy here, bro. It is the coconut milk base. Some shops cook it thicker and richer; some cook it more soupy. That difference alone can shift the fat content by 5 to 8g per serving.