How long it would have taken for Majin Buu to have eaten a planet made of sweets?

[Steven Bloodriver]

Let's say Shin, the Eastern Supreme Kai, had used his Power of Creation to keep Super Buu patient enough to wait out the hour he was given by Piccolo by giving him an entire planet full of junk food, how long it would have taken for the Majin to gobble up a planet as big as Mars and would it have been enough for Trunks, Goten, and Gotenks to finish their training in the Hyperbolic Time Chamber, or at least for Ultimate Gohan to have arrived from having a great deal of his hidden power awakened at the time by the Eldest of the Supreme Kais?

[Polyphase Avatron]

If he ate it at the same rate he ate other things it would take many years. If he shrunk it down to eat it faster then who knows.

[Pantalones]

We never really see Buu sat down in front of a massive amount of food and rapidly scarfing it down Goku style, do we? I imagine when faced with a snack pile of that magnitude Buu's eating pace wouldn't be as slow as we saw with, say, a single Dabura cookie.

So an entire planet of junk food would still take some time, but Super Buu isn't as food obsessed as Fat Buu was so I figure he would get tired of it before too awfully long and just blow the whole thing up (or as suggested, shrink it to eat whatever was left all at once like a big jawbreaker or something.)

It would definitely give them more time than they had in the way things went canonically, though! Maybe Gotenks would be Ultimate Gohan level (or even above!) due to having more time to train.