The 34-year-old model says every morning she will make the warm drink to "kick start" her digestion, which is swiftly followed by a nutritious smoothie, reported Contactmusic.
"So one of my favourite things to have in the morning is hot water with lemons. It's a really great way to kick start your digestion, it's full of vitamin C.
"After I've made my hot water and lemon, I'll then make a smoothie, and these are some of my favourite ingredients...It is a great source of protein," Kerr says.