Sinitta told the Sunday Mirror that her best friend has started eating the pudding on a daily basis, as a result of the backlash regarding John & Edward being chosen over Lucie Jones.
The singer said: "He has a two-packet-a-day problem or habit - it's his comfort food. He walks round with a packet of cigarettes and a packet of Angel Delight.
"He will have a bowl of pink Angel Delight at home or even in the back of a limo. It's very '80s and he's an '80s child."
Sinitta added that Cowell has been deeply affected by the recent criticism he has received.
"He does care. He does listen," she insisted. "But if he did make a mistake, cut him some slack. He realises people are disturbed by the result. He listens to the voters, even if it's not always his taste.
"But it doesn’t mean he sits at home listening to John & Edward. It was a shock when John & Edward stayed. But I think they sing as well as a lot of people out there sing."
The 41-year-old also denied claims that the results on The X Factor are predetermined.
"It's not fixed or staged," she stated.