[kossae]

I think this is the likely reason. For instance, 5 years ago when I'd never tracked a calorie in my life, I had no idea how bad most of the things I was eating were for me, or even how good some of the other things were. Quantifying this over time, as well as similar recording for workouts, got me to the point where if you took the tracking tools away I would still be able to roughly (but accurately) gauge both food intake and fitness progression intuitively.