Why does one of the most familiar numbers on a nutrition label turn out to be far more complicated than it looks? What can a can of fizzy drink teach us about thermodynamics, human metabolism, and the strange ways scientists measure energy? Professor Hannah Fry and VSauce’s Michael Stevens dive into the weird science of calories. From century-old experiments involving fire, body heat, and human digestion to the hidden quirks of modern food labeling. Do “negative-calorie” foods really exist? Where does burned fat actually go? Why chewing matters more than you’d think, and how your body is constantly leaking energy out into the universe. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Video Editor: Adam Thornton + Oli Oakley + Jack Meek Animator: Sam Benson Video & Social: Bex Tyrrell Assistant Producer: Lucy Lipscombe Producer: Simona Rata Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn