People think Milo is a health drink because of the ads with kids playing sports. The Milo powder itself is mostly malt and sugar, and the kopitiam version makes it worse by adding condensed milk on top. That is why a glass of milo ais lands around 250 calories, closer to a dessert than a drink.
It is not evil, but be honest about what it is. A milo ais is a 250 calorie sweet treat, not a free drink to wash down your nasi lemak. Pairing a 250 calorie drink with a 556 calorie nasi lemak turns an 800 calorie breakfast into a thing you did not plan for.