If jack said no to the nil by mouth task..
 

..what would they have done with all the prepared food? Seems risky to be willing to waste that much, it just looks silly in my eyes.

£30 worth of McD;s. Is this even an issue!

They would have let him eat it and carried on with the day

They primed Jack to say yes. When he won £23k, he was so euphoric henever going to decline any task and given the poll said he wasn't a team player he wants to prove this wrong. The producers know Jack very well.

The crew would have probably eaten it

it would just have meant that 1k or whatever it was would not get added to the prize fund