Pyke was born at Gloucester Terrace, Paddington, London, the son of Clara Hannah Lewis and Robert Bond Pyke, manager of a wholesale confectionery business. He went to St. Paul's School, Barnes, London, where he found he had a "certain bounciness combined with a lack of self-consciousness." He worked briefly for an insurance company before emigrating to Canada to attend Macdonald College, McGill University, Montreal, studying agriculture, gaining a BSc in 1933. During summers there, he worked as a farm labourer. He remained in Canada for seven years. He returned to the UK and in 1934 became chief chemist at Vitamins Ltd., Hammersmith, London. He worked with Professor J.C.Drummond of University College, London on vitamin research. He gained a Ph.D. in biochemistry in 1936. On 23 August 1937 he married Dorothea Mina Vaughan, an accountant. They had a daughter, Bessie, and a son, John.
Wartime scientific career
In 1941 Pyke joined Professor Drummond at the Ministry of Food where Drummond was scientific advisor. They studied the nutritional effects of food restrictions due to wartime shortages. He lectured on practical nutrition for those working in institutions that provided food: these lectures were published by H.M. Stationery Office under the title The Manual of Nutrition . He suggested using excess human blood supplies to make black puddingfor the masses, and supported the idea of using rose hip syrup to replace imported orange juice. He was a scientific advisor to the Allied Commission for Austria in 1945–6, after which he worked as Principal Scientific officer at the Ministry of Food, continuing to work on institutional diets and nutritional education.
Later scientific career
He joined The Distillers Company in 1949 as the deputy manager of the yeast research division at Glenochil Research Station, Clackmannanshire. In 1955 he became manager, retiring in 1973.
Pyke wrote dozens of scientific papers and publications on food and nutrition, and their links to technology and social change. A list of his published books is below.
Manual of Nutrition
Townsman's Food
Automation: Its Purpose and Future
Nothing Like Science
About Chemistry
Slaves Unaware?: A mid-century View of Applied Science
Nutrition
The Science Myth
The Boundaries of Science
The Science Century
Food & Society
The Human Predicament: An anthology with questions by Cedric Blackman
Curiouser and Curiouser: Dr. Magnus Pyke's Amazing A-Z of Scientific Facts
Weird & Wonderful Science Facts
Dr.Magnus Pyke's 101 Inventions
Broadcasting career
Pyke's early broadcasts were from April 1953 in talks about science and technology on the BBC's Home Service, Third Programme, Light Programme and the educational programming of Network Three; later he also broadcast on Radio 2 and Radio 4. In 1974, he appeared on Yorkshire Television's Don't Ask Me and then Don't Just Sit There, in which he and other experts such as David Bellamy, Rob Buckman and Miriam Stoppard fielded popular science questions. His exuberant delivery, with very animated and passionate speech and gesticulation, made him famous. He was a panellist on radio programmes such as Any Questions? and Just a Minute and a guest on Desert Island Discs. He called this period his 'sixth life.' In September 1975, the popular science magazineNew Scientist asked its readers to name the best-known and most characteristic scientist. Pyke came third after Isaac Newton and Albert Einstein. On 10 December 1975, Pyke was celebrated on This Is Your Life, a Thames Television production for ITV. He won the PyeColour Television Award for most promising male newcomer to television and the Multi-Coloured Swap Shop Star Award for expert of the year.
Pyke retired from regular broadcasting in 1980, save for occasional TV appearances. He nursed his wife at home in Hammersmith until her death in 1986. He survived a brutal burglary at his home in 1988 by a thief, leaving him badly injured. He died on 19 October 1992 at Elmsbank Nursing Home, Carlton Drive, Wandsworth, London.