Thats a good question Plonk. Axolotl can be over fed . A full grown axolotl, approx 25-30 cm may only 'need' feeding maybe once/ twice a week depending on how warm they are..the cooler they are the less need to feed. My juveniles which are approx 6 inches are now being fed every other day , small juveniles daily and larvae (babies)twice a day. If your future axolotl is anything like my gang it may claim to be starving and need to be fed far more. I personally feed my adult male one earth worm ( approx 8cm in length ) alternate days and his offspring are now down to one worm each alternate days..they where starting to look like moving barrels ! my youngsters especially will accept food, my adult will reject food if he is not hungry.
It will also depend on what you choose to feed your axolotl. I prefer to give live earth worm whole or chopped with occasional thin strips of raw tiger prawn, lean meat,squid, heart. The youngsters get occasional pellets so that when they are rehomed I can pass on something that I know they will eat.
Keep asking the questions...don't be put off!
