Generally true for me, as well. Times I've been the most active (eg military training), I "should have" been thinner. It wasn't the case. I like that quote; that's an interesting way to put it.

I like the Gary Taubes (and others) theory, which is the other way around: it's not that you're overfat because you aren't hamster-wheeling it enough; rather you'll spontaneously become more active when you fix the metabolic problem. When you're overfat mainly because of garbagey food, you're still energy-starved at a cellular level. Fix the diet so that you use food and stored body energy properly, and you'll start exercising. You might need less sleep, you'll be more fidgety, you'll want to move more.