Serunding is that fragrant meat floss you get with ketupat and lemang during raya. A normal topping portion is only 2 or 3 tablespoons, around 95 calories, so it is not a big deal in small amounts. But per gram it is dense, close to 470 calories per 100g, because all the moisture is fried out and what is left is meat, coconut and oil.
The trap is treating it like a free sprinkle and piling it on, especially next to lemang or pulut which are already calorie dense. A little goes a long way on flavour, so use it like the condiment it is and you are fine.