The Claim
Caffeinated energy drinks containing 280 mg of caffeine and limited electrolytes or carbohydrates significantly reduce fluid retention compared to water, with a Beverage Hydration Index (BHI) of 0.86–0.91 at 240 minutes, indicating a 9–14% reduction in hydration efficiency.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
Drinks with 280 mg of caffeine and minimal electrolytes or carbohydrates result in 9–14% less hydration efficiency than water after 240 minutes, as measured by the Beverage Hydration Index.
See the scientific wording
Caffeinated energy drinks containing 280 mg of caffeine and limited electrolytes or carbohydrates significantly reduce fluid retention compared to water, with a Beverage Hydration Index (BHI) of 0.86–0.91 at 240 minutes, indicating a 9–14% reduction in hydration efficiency.
Caffeine blocks a natural signal in the kidneys that tells the body to hold onto salt and water. Without enough salt or sugar in the drink to help the kidneys reabsorb that salt, the body ends up flushing out more water than it keeps, leading to less hydration than plain water.
What the research says
1 studyThis study found that energy drinks with a lot of caffeine but little sugar or salt make your body lose more fluid than water does — so they’re worse at keeping you hydrated. The numbers show they’re about 14% less effective than water.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.