The ZeroFive100 project challenged everything mainstream medicine tells us about fuelling our bodies. Eight runners, including Olympic medallist James Cracknell, completed what amounts to a marathon each day for five consecutive days, consuming zero calories throughout the entire event. Every step was powered purely by their own stored body fat.
Why This Changes Everything About Fat Metabolism
When Dr Ian Lake first approached me about participating in and funding this audacious experiment, I knew we were onto something revolutionary.
This general practitioner with type 1 diabetes had spent years successfully managing his condition through a ketogenic diet, witnessing firsthand how the body thrives without constant carbohydrate intake.
Yet medical professionals continued dismissing low-carb approaches, often frightening patients with warnings about hypoglycaemia and ketoacidosis.
"I wanted to reassure people that the ketogenic diet was a safe practice," Dr Lake explained. "I thought the best way to get the point across was to be as outrageous and audacious as possible."
As someone who had already experienced the transformative power of metabolic flexibility through my own fasting experiments, I understood exactly what Dr Lake was trying to prove.
His proposal was beautifully audacious: if eight people could run 100 miles over five days without eating anything, then skipping breakfast or following a low-carb diet must be be possible and safe for most people.
Each runner needed to utilise approximately 20,000 calories entirely from stored body fat during the event.
