It feels a bit like - well could I engineer myself to require 1500 calories a day instead of 2000. Maybe. But as a result there would definitely be some downside, maybe I'd be less physically strong, or have less endurance, or have a bit less processing power, or have to rest more, etc. If we straight up designed a more efficient body, then I'd rather keep eating 2k and be "more powerful", or maybe I'd go to 4k!
Maybe I can sleep for 2 fewer hours and retain the same or more productivity. Or maybe I could sleep for the full amount of hours but be more well rested and as a result be more productive in the awake time. That sort of thing.