Probably, since there are a lot of good prepared foods like flakes, pellets, wafers that cover all the nutritional needs of most fish, so if you get a good brand (Hikari, New Life Spectrum aka NLS, Ocean Nutrition), you can feed that mainly and then supplement with the other foods a couple times a week. I would definitely add veggies at least once a week, though.
There are exceptions to this, such as puffers that must have frozen or live foods (won't touch flake or pellet).