Payne welcomed his son Bear with singer Cheryl in March.
"It's changed me in every single way. It's the first thing you think about in the morning and the last thing you think about at night... It's his first Christmas. He's only going to be interested in the wrapping paper, so buy the shiniest one," Payne told etonline.com.
The 24-year-old singer is looking forward to the festive period.
"My holiday plans are to spend some beautiful time with my son and to eat my own weight in lovely Christmas food. You might see a different Liam after Christmas and then you'll see post-Christmas Liam with a new year resolution, hopefully," he said.