Fish ball noodles is genuinely one of the friendlier noodle dishes at the hawker centre. At 390 calories for dry and 370 for soup, it's not going to wreck your day. The reason the number stays manageable is simple: fish balls are mostly fish paste and water, not deep fried, not coated in batter. Six pieces at around 120g only comes to 110 calories. The bulk of the calories here is the noodles, 130g of cooked mee or kway teow at 185 calories, which is just carbs doing carb things. The lard oil in the dry version adds 70 calories and a lot of the flavour, bro, let's be honest.
What actually shifts the maths is how much lard the uncle uses and whether you go soup or dry. Soup version saves you about 20 calories because the condiments are lighter and there's less oil. Ask for less oil on the dry version and you could probably shave another 30 to 40 calories off. The other variable is add-ons: most stalls let you top up with extra fish balls or a slice of fish cake. Two extra fish balls or one slice of fish cake pushes you to around 450 calories, which is still not crazy, but it adds up if you're tracking. Stick to the standard six fish balls, go soup if you can, and you've got a 370-calorie lunch that actually keeps you full.