Your protein shakes can also contain a hefty amount of calories and carbs and act as minor meal replacements for convenience on busier days. You can mix protein with milk, dextrose, quick oats, fruit, peanut butter, nutella, or any number of additions to help replenish the glycogen and amino acids your muscles need after a workout.
Between a real meal with carbs and meat, the meal would be preferable. But between a protein shake a donut or candy bar from work, the protein shake is going to be the better option. Whey protein would be helpful whether on a bulk or cut because it's a very controlled addition to your macros. You can keep your protein high and your calories low on a cut with a protein-only shake, and you can add both calories and protein to your shakes with peanut butter or milk or dextrose if you have room to bulk.
Brent is the weightlifting coach at Dallas Strength and Conditioning. He has competed at USAW Nationals in 2015 and has been active in competition since 2006.