I nursed exclusively for about a year and a half, then supplemented with food for another 2 years, but she never ate much real food til I cut her off completely. I felt like a milk cow. Anyway, since I worked full time, I pumped, and I found that pumping really increased my supply. I would pump during off times when she wasn't hungry. Pretty soon I'd built up a huge reserve supply. I know it's weird but it was almost like exercising - I conditioned my body to produce more than we ended up needing.

Good luck!