The tofu part is genuinely good for you. Silken tofu is about 55 calories per 100g with 5g of protein, so the 150g in a regular cup is 80 calories and 7g of protein. Kawaling Pinoy's recipe card comes out at 213 calories per serving, which matches a vendor cup. The rest is arnibal: brown sugar boiled into a syrup. A vendor ladles in about 40g of it, which is 110 calories of straight sugar.
Ask for 'konting arnibal' (less syrup) and the cup drops to about 150 calories. Most magtataho will do it without blinking. The sago is minor at about 30 calories for a spoonful, though it is also just starch. A large cup at 30 to 35 pesos is about 350 calories, because the vendor scales the syrup with the tofu.
The strawberry taho from Baguio is a different animal. The strawberry syrup is sugar with fruit flavour and they tend to pour more of it, so a regular cup is closer to 260 calories. Same for the ube and pandan versions at mall stalls, which also add condensed milk. Taho is a 20 peso breakfast that is fine at 220 calories. It is not fine as a 350 calorie large on top of pandesal and coffee.