"Brush your teeth" never worked me. I'd get hungry and eat anyway. Two servings of whey protein powder a day, on the other hand, completely nukes my interest in snacks.

As for HN and such, I find my interest waxes and wanes. I definitely have days where it's a big distraction, particularly when I'm waiting 10 seconds for something to compile and come back ten minutes later. Then there are days when I'm too focused on coding, marketing or whatever I'm doing for it to be a big distraction.