Singer Harry Styles takes bullet coffee to remain slim as it controls his hunger pangs.

The 21-year-old singer uses the method to keep his body trim to fit in his skinny jeans, with a 26 inch waist, reports mirror.co.uk.

"Bullet coffee. It's black coffee with a spoonful of butter in it and a spoonful of coconut oil, all mixed up together. I've been on it for two days. You don't get hungry,` The Sunday Times Style magazine quoted Styles as saying.

His fellow bandmates revealed that Styles is into "protein-and-Pilates" while Louis Tomlinson prefers a pasties and bakes.

Styles also shared that he likes to keep fit by doing meditation and Pilates, and stays active by boxing and running.