Do You Lose Calories When Losing Blood? The Surprising Science Explained
                                
                                
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                                    3 min read                                
                            
                                According to the American Red Cross and Mayo Clinic, your body can burn an estimated 500 to 650 calories in the process of replacing a single pint of donated blood. This widely cited figure raises an interesting physiological question: do you lose calories when losing blood, and what is the scientific mechanism behind this caloric expenditure?