The bowl of kway is the cheap part of the calorie bill. 300g of flat rice sheets in braised broth is around 190 calories, and the broth itself adds very little. The plate next to it is the problem. Three slices of braised pork belly are about 250 calories on their own. Add 60g of intestines and pig skin at about 90, a braised egg at 75, and some tau kwa and tau pok at 50, and you are at 650 before you have finished counting.
The pork belly is the swing item. A S$5 set usually comes with 2 to 3 slices. Ask for lean meat or pork shoulder instead and the same set drops to roughly 520 calories. Ask for extra belly and it can pass 850. Nobody weighs it, so what lands on the plate depends on the auntie and how much she likes you.
One honest thing about kway chap. The offal gets blamed, but 60g of braised intestines is about 90 calories, less than one slice of belly. The intestines are mostly protein and some fat. If you like them, keep them. Drop a slice of belly instead and you will save more.