The Science of Hydration: Does salt water have calories?
                                
                                
                                •
                                
                                
                        
                                    
                                    4 min read                                
                            
                                According to nutrient data, a 100-gram serving of pure salt contains zero calories. This simple fact is central to the question, **does salt water have calories?**—and the answer might have a more complex impact on your diet and hydration than you think.