> 1. Protein takes more calories to digest (many people unintentionally eat more protein on keto, though keto is actually about fat intake and protein can break

> 1. Protein takes more calories to digest (many people unintentionally eat more protein on keto, though keto is actually about fat intake and protein can break ketosis through gluconeogensis) I'm pretty sure this is a myth, unless you're eating such a small amount of fat that you can't get energy anywhere but though gluconeogensis. Your body uses gluconeogensis to create glucose for the cells that need it. It's not an efficient way to produce energy for cells that can just use ketones. > Your anecdata is likely accounted by: I suspect it's mostly that I didn't store all of the excess calories I ate. E.g. I've seen excess fat in my stool. When people say CICO doesn't work, they don't mean thermodynamics doesn't work. They mean that not all calories consumed (i.e. eaten) get burned or stored. If you limit "Calories In" only the calories that get burned or stored, then sure, tautologically, CICO is correct.