Gassy baby

My 4 week old daughter is breastfed and due to slow weight gain (long story for another post, she is gaining now) I give her 1oz of breast milk via bottle 3 times a day. Intermittently she’s always had gas and occasional spit up. I’m assuming this must have to do with my diet. She’ll be sound asleep and start screaming, pass gas and go back to sleep. It also causes fussiness throughout the day as I can tell her belly tenses up. I eat a pretty bland diet, only drink water, not many vegetables and no dairy due to her gassiness. I use Little Remedies gas drops and last night started gripe water which seemed to work really well. I hate having to treat the gas and would rather eliminate it. Any ideas for a healthier diet?