My parents both also worked full time, but never bought sweets (candies), or fastfood.
We always - even as small children - prepared our own breakfasts (supervised by my father), and often, our own lunch; and we (my brothers and I) once we hit the teenage years were encouraged to cook and prepare meals for ourselves and for the family; in general, my mum usually prepared evening meals, though less so, in latter years.
Instead, we were encouraged to snack on fruit - there was always fruit in a bowl, apples, pears, bananas, plus whatever was in season - and cheese and bread, if necessary.
The upshot of this is that my brothers and I eat vast amounts of fruit to this day, and never (or, hardly ever) buy sweets, (candies) or similar snacks.