This is exactly how some people explain the way they feel after a cup of bulletproof coffee.
To put it in more sciencey terms (eh, not really), carbs will satiate you better for short term durations than any macronutrient. But if you can't eat anything for long periods of time then you need a slower burning source of energy. Enter fat. It lasts longer, has more caloric (energy) density, provides the body with fuel to last a lot longer than fast-burning carbs that trigger insulin release. Fat triggers no (or barely any) initial insulin release when consumed, so you don't have the associated reactions either.