An curved arrow pointing right. The old world tradition of adding butter to coffee has recently re-emerged as a performance enhancer embraced by the likes of Bulletproof Executive founder Dave ...

An curved arrow pointing right. The old world tradition of adding butter to coffee has recently re-emerged as a performance enhancer embraced by the likes of Bulletproof Executive founder Dave ...

A case in point is Llorente's penchant for plonking a dollop of butter in his coffee, an addition that supposedly increases energy and concentration while also keeping hunger at bay. Known as ...