The Price Tag singer said: “I boil down chickpeas and garlic and drink that straight. The house smells lovely.”
She explained the logic behind the health trick by comparing herself to a footballer.
“The way I look at it, a footballer wouldn’t play in flip flops of dip their feet in acid and expect to get to David Beckham’s level.
“My voice is my living, so I’ll be looking after it.”
Jessie, 25, also revealed that, despite her huge success, she’s still the same person she’s always been.
“I’m the most un-divaish person you’ll meet. I’m never rude to people and I’m always on time.
“I have always been the first person on the dancefloor. Before fame people thought it made me a good laugh, now people point at me and call me an attention seeker!”
And she says she tries to not let what people say get to her.
“I’m very aware of the way people can view me but I’m very aware that I just have to enjoy my life.”
The former Voice UK coach also recently shrugged off comparisons to Miley Cyrus.
She said: “You know what? I have to see it as naïve and lazy comparisons. It used to bother me, but it doesn’t anymore. I know what makes me different. You’d never see me kissing a doll in a swimming pool!”