Wow, They are some seriously obese catfish.
If you don't get them into a more healthy condition you may well have health issues with them in the future.
Good luck with the veges, mine wont touch them. :roll:
If they were mine, I would only be feeding them once or twice a week until they lost a bit of "condition". They will get plenty of nutrients from the driftwood.
From looking at your photos and your fanning descriptions, I would say that you have at least one male.