An adult male needs around 2500 kcal per day. This works out to 2906Wh. The battery in a Nexus 5 is around 8Wh, for comparison. The question then becomes: how many hours would the battery last running the Komodo 9 engine full-out?

That would be an interesting matchup. I bet a grandmaster could play slow enough to kill the battery on the phone. A human could go a day without eating no problem. There's no way the phone could go a day without charging while running 100% CPU.