Sugar-free energy drinks deliver caffeine without the sugar load. This one has 5 kcal per 100 g. A randomized crossover RCT in 34 healthy adults (Shah et al., J Am Heart Assoc 2019) found energy drinks raised QTc by ~18 ms and elevated blood pressure versus placebo. Mind the caffeine total.
How should I track Red Bull Sugar Free?
Liquid calories from Red Bull Sugar Free are easy to overlook because drinks do not trigger the same fullness signals as solid food. A meta-analysis (Wehling & Lusher, Am J Clin Nutr 2021) confirmed that people underreport beverage intake more than solid food. Most people pour 30–50% more than the label serving size without realizing it. Use a kitchen scale to weigh your glass or bottle once — you will know your exact pour going forward. This one calibration step can save you from hundreds of untracked calories per week.