I feed mine once a day. He is only 6 months old. He eats some of it in the morning and then comes out again in the afternoon and eats the rest.

Daily.

Sometimes the indoors ones will get a fasting day. Outsides get fed 3-4 times a week prepared. However they have natural foods available 24/7 in the pens.

We feed our 7 year old Greek (guesstimate for age) twice daily.

He eats until he's full and then walks away. Since he is maintaining at about 348 grams I feel this is working for him.

(We soak him twice a week. He already pees at every meal so it seems he is getting enough water from his meals otherwise.
We do mist him every other day.)

i feed them twice a day, in the morning (i just put it into the dish, and usually all of them suddenly wake up and go to the dish.. hehe..) and evening (before they go to sleep, or else after i clean up all of them)