hmmm...I wouldn't recommend only once a week unless your cham seems to be OK with it, but if the poor thing is starving waiting for food every week then it is obviously not a good idea.
Think of how it would be in nature - sometiems they may go a few days without food, but the fact that they eat insects (and veiled's eat vegetation, too) there would often be enough to go around. I think most folks feed them at certain times of the day if they don't free range. Just not too late in the day so they have time to digest before lights out.
My suggestion would be to cup feed and observe your cham's behavior for a week or so. He may prefer to eat right after his morning bask and that's it, or he may want to eat twice a day. Also, vary the food items ocassionally so he doesn't tire of the same ol' crix 
hope this helps!
lele
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0.1 veiled - Luna
0.2 felines - Kyndra and Líta
1.0 African Clawed Frog - Skipper
0.5 Mad. Hissers
0.1 Chilean Rose Hair Tarantula (no name yet)
?.? Goliath Bird-Eater Tarantula (no name yet)