Red bull sugar-free is a carbonated beverage that vitalizes body and mind without sugar and only 5 calories per 8.4-fl oz can. When to drink: Red Bull is one of the best energy drinks to have by your side and is appreciated throughout the world by top athletes and busy professionals to college students and travelers on long journeys. For those who have to stay on their game during intense meetings or creative brainstorming sessions, in action with teammates or competitor, or simply want to get the most out of life, a chilled can of red bull sugar free gives you wings without sugar.