The Australian food critic, who judges MasterChef Australia alongside chefs George Calombaris and Gary Mehigan, said that the next series of his programme will be all about the food.
Preston told the Herald Sun that Channel Ten hopes to bring the competition back to basics this year, saying: "The first thing we look at is whether they can cook.
"We could pick nuff nuffs who couldn't cook and it would make great TV, but it is not really what it is about."
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He said of My Kitchen Rules: "TV shows are about ratings. MKR has been fantastic and everyone has loved watching it because they have taken a leaf out of [renovation reality series] The Block's [book]."
Last year, Mehigan said of MasterChef's main competitor: "My Kitchen Rules is quite obviously a blatant rip-off. The set looks similar to ours and the phrases are the same," while Preston added: "I hear that [My Kitchen Rules judge] Manu [Feildel] has borrowed my speech just in case he wins a Logie this year."
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Watch the My Kitchen Rules elimination of Andrew and Emma earlier this week (Australian users only):