For many, the festive period is a time to binge on food and drink, but Guardiola has warned his players not to give into temptation.
Man City face Nottingham Forest in the early kick-off on Saturday (December 27), and the Spaniard wants his players at their peak.
Speaking after their comfortable 3-0 win over West Ham, Guardiola admitted he weighed his players following the game.
“Yesterday every player made weight,” he said.
“On the 25th, I will be there controlling how many kilos come up.
"They come fatty... listen, I didn't say one word I've said today to make them feel... no, this is the truth.
“The moment they arrive after three days, I want to see how they come back.
"They can eat at Christmas, but I want to control them. I have to make a selection for the 27th against Nottingham Forest.
“Imagine one player who is now perfect arrives with three kilos more, he will be in Manchester, he won’t travel to Nottingham Forest, that's for sure.”