Energy balance

While fat-free mass gains are similar, 16:8 TRE results in less fat mass accumulation and lower total training volume compared to continuous feeding during a caloric surplus.

Be aware that if you switch to an 8-hour eating window, you might naturally train for less total volume and accumulate slightly less fat than if you ate all day, even in a surplus. This isn't necessarily bad—it might mean you are more efficient with your energy—but it is a trade-off to consider if your goal is maximum fat gain (bulking).