Kuih Bom is that round, golden, sesame-coated ball you see at kuih stalls and pasar malam. The dough is glutinous rice flour mixed with coconut milk, deep fried until puffed up, with a soft sweet coconut filling inside. At 210 calories per piece, it is not catastrophic if you eat one. The problem is nobody eats one. The calories come from three places: carbs from the glutinous flour, fat from the coconut milk in the dough plus the frying oil absorbed, and sugar from the gula melaka filling. Fair warning: these numbers are a ballpark estimate because detailed lab data for kuih bom specifically is thin, so treat it as a reasonable guide rather than a precise count.
What changes the number most is how much oil the dough absorbs during frying. Freshly fried pieces that have been properly drained will be on the lower end. Ones sitting in a tray soaked in oil, or fried at too low a temperature, absorb more fat and could push past 230 calories easily. The filling matters too: the chocolate variant in modern kuih shops runs about 230 calories versus the classic coconut version at 210. The sweet potato dough version (keledek) drops to around 185 calories because less glutinous flour is used. Two pieces of the classic version is already 420 calories, which is a full meal's worth of calories for some people. One is fine as a snack. Two is a decision you should make consciously lah.