I've never taken a proton pump inhibitor but I read this short account of one person's experience. She's got a lot of info about her journey through IBS and GERD. She's had to do different things than just eat paleo or primal so you might find some info looking around her site.
Proton Pump Inhibitors Suck | Melissa McEwen's on food anthropology, economics, and culture
Female, 5'3", 49, Starting weight: 163lbs. Current weight: 135 (more or less).
Starting squat: 45lbs. Heaviest squat: 180 x 2. Heaviest Deadlift: 230 x 2