Low calorie, no calorie and so sweet. Artificial sweeteners just seem too good to be true. Is there a catch? We dig into two big questions: Do artificial sweeteners cause cancer, and are they making us fat? We talk to Prof. John Glendinning, Prof. Susie Swithers, Dr. Kieron Rooney, and PhD student Jotham Suez about the latest research. Plus we do a fun experiment with PJ Vogt and Alex Goldman from Reply All!