Claim: Does coffee dehydrate you?

Coffee does not dehydrate you, as supported by multiple health sources. Researchers and health professionals agree that while coffee has a mild diuretic effect, it is offset by its high water content, especially for regular drinkers. There is no substantial evidence to suggest that moderate coffee consumption leads to dehydration, even during exercise. Some alternative sources may claim otherwise, but they lack robust evidence to support such assertions. The models diverge sharply — treat this as higher-uncertainty. Perplexity comes in highest (95%), while Gemini is lowest (50%). OpenAI expresses higher confidence than Gemini on this claim. While the evidence strongly supports that coffee does not dehydrate, some might argue that excessive caffeine intake could lead to dehydration if not balanced with non-caffeinated fluids. However, this perspective primarily applies to non-regular coffee drinkers and does not significantly alter the overall conclusion that moderate coffee consumption is hydrating. The consensus remains that coffee contributes positively to hydration levels in healthy adults.