I drink protein shakes as one or more of my meals on a regular basis. I keep a tub of protein handy, and I am more likely to have a whey shake for breakfast or dinner than an actual meal.
Sometimes, I have an actual meal but limit the portions substantially so that I can meet my macros by having a few scoops of whey instead. Pretty healthy and easy to meet your goals.
To the OP who remarked that people don't eat meal sticks, MREs are extremely common -- people who spend any extended amount of time outdoors or in inhospitable climes (ever been on a long and arduous climb or hike?), military personnel on the field, and folks who have traveled to exotic locales all eat MREs, which are nothing more than glorified "meal sticks".
In addition, any reasonably fit athlete will consume some pretty tasteless food in the form of protein shakes and other healthy "meals". Sure, they have flavor, but that's only to mask what would otherwise be absolutely unpalatable. And after a while, you even start associating some flavors negatively (after 4 years of having a vanilla whey shake with peanut butter and banana, I am staying far, far away from the combination for a long time to come).