A postman ate nothing but McDonald's food for 30 days - and LOST weight. Ryan Williams, 29, launched his fast food mission to try and disprove Morgan Spurlock's famous 'Super Size Me' challenge. Spurlock's 2004 American documentary saw the director also eat nothing but McDonald's for 30 days - and gained almost two stone. But Ryan, from Cheltenham, Glos., felt that Super Size Me presented a skewed version of the challenge. He and wanted to prove it is possible to get in shape in 30 days on a McDonald's-only diet.