This systematic review compared how consistently between-meal protein supplementation resulted in changes to lean mass, body fat, total body mass, and the ratio of lean to fat gains, when compared to with-meal protein supplementation.

Both approaches produced similarly consistent gains in lean mass, and the with meal supplementation strategy more consistently produced losses in fat mass, drawing into question protein-spread theory. It is still possible that evenly distributing an appropriate daily intake of protein (1.6 g/kG - 2.2 g/kg while not dieting) between boluses consumed every 3-5 hours would maximize hypertrophy, but it may not make a detectable difference in short term studies on individuals with a low training status, which dominate the existing literature.

Adding snacks between meals may be more effective at inducing an energy surplus. Likewise, increasing the portion sizes of the protein-containing foods in your meals, or drinking protein shakes with meals, might result in compensatory eating behavior that keeps your energy intake roughly stable, while also increasing your protein intake. The former may be an easier approach when bulking, the latter when cutting.

However, it should be noted that neither strategy appears more successful than the other for gaining muscle mass, despite mechanistic evidence pointing to the advantage of protein-spread theory. With that said, its probably not a bad idea to roughly evenly spread your protein between your meals if you can manage it without a hassle.
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THE EVIDENCE: Hudson et al. Effects of protein supplements consumed with meals, versus between meals, on resistance traininginduced body composition changes in adults: a systematic review. Effects of protein supplements consumed with meals, versus between meals, on resistance training–induced body composition changes in adults: a systematic review | Nutrition Reviews | Oxford Academic