If you aren't trying to completely get rid of ultraprocessed foods, high fiber breakfast cereals can help with fiber. General Mills Fiber One Original or Kellog's All Bran Buds for example. The former has less sugar and slightly more fiber, but the latter has a better mix of soluble and insoluble fiber. Fiber One is 17 g insoluble/1 g soluble, and All Bran Buds is 12 g insoluble/5 g soluble.