I do a mile a day, 5 days a week.
Sometimes I'll walk it. Sometimes jog or run it. If I'm in a hurry, I run it. If I'm relaxing, I'll take it easy. I hate the clock, I get way too lazy knowing "29 minutes left..."
I've noticed a huge difference. Haven't changed diet yet, but I feel great, never tire at anything outside of the gym, and appetite has gone up a lot for clean foods.
IMHO, lots of water & lots of walking forgive a lot of bad habits.