Sounds to me that you might have H. pylori infection with all that heartburn. Maybe our body ecologies are different but I lose weight drastically when dieting. Don't you think eliminating predominantly carbohydrate-rich foods will induce weight loss? I see that you mention mostly fruits, veggies, brown rice, figs.. these seem like menial snacks to me. Look at things like Nutrisystem or Jenny Craig, their diets are very complementary-"lean". Despite being healthy, the calories are too low and don't support an active lifestyle-unless you're overweight and pushing to lose the ibs.