[8] He recalls that hearing Stravinsky's The Rite of Spring played loudly on a family friend's state-of-the-art hi-fi, at the age of fourteen, first enlightened him to the power of music.

Regular contributors included Richard Gott, John Gittings, British historian Timothy Mason, JG Farrell, Ian Hamilton, and Kevin Crossley-Holland.

OO introduced the film commentary allied with Cahiers du Cinéma by Ian Cameron, Mark Shivas, VF Perkins, and others, who later founded Movie magazine.

[8] Along with Tony Palmer of The Observer, a Sunday newspaper, he was one of the leading figures in the emergence of British rock criticism during the late 1960s.

[11] Helped by his association with The Guardian, Cannon was able to contribute more substantial articles to the Los Angeles Times and the Chicago Sun-Times, and to underground magazines such as Creem.

[13] He recalls that, together with Rolling Stone journalists David Dalton and Jonathan Cott, he joined Granada Television documentary-makers such as Jo Durden-Smith, John Sheppard and Michael Darlow in devising "prime-time networked shows designed as anthems of the revolution".

[8] He also directed the film of Frank Zappa's performance at the 1970 Palermo Pop Festival, for RAI, Italy's national public broadcaster.

In his address, he discussed rock music's inspirational role on the lifestyle of contemporary youth and also its ability to provide "the catalyst for styles of death", with regard to the counterculture-related deaths of Sharon Tate in Los Angeles, Meredith Hunter at Altamont, and Weather Underground radical Diana Oughton.

Brian Gearing, his successor as editor, wrote: "Cannon arrived, backed by a young and talented staff … the changes he made were the most far-reaching ever to be introduced … At the end of the 1970s, Radio Times … was still Britain’s largest and most successful magazine.

His focus on fitness resulted in regular coverage of the 'Getting in Shape' citizen running project, which he developed from Fun Runner ‘82, and in the 1982 New Year issue of The Sunday Times ran a feature by Cannon with the title ‘Dieting makes you fat’.

[23] With co-author Hetty Einzig, Cannon then wrote the book Dieting Makes You Fat, which became a UK number one best seller.

The result was a Sunday Times front page lead news story and a full-page inside feature article.

[51] While writing Caroline Walker's biography,[39] Cannon discovered that in 1976 his late wife and co-author had been prescribed what would now be seen as a gross overdose of the toxic antibacterial drug co-trimoxazole.

[52] He became interested in antibacterial drugs in general and in 1991, supported by a Winston Churchill Travelling Fellowship, he interviewed various authorities.

[53] He concluded that the overuse and abuse of antibacterial drugs in human and animal medicine and rearing was evolving drug-resistant bacteria and already amounted to a catastrophe.

[56] The method devised by the secretariat of assessing evidence as convincing, probable, possible, or insufficient was adopted by the World Health Organization.

In Brasília, he worked with Denise Costa Coitinho as consultant to the Coordenação Geral de Alimentação e Nutrição (CGAN, the department of food and nutrition) at the federal Ministry of Health.

Cannon was a member of the official Brazilian government delegation to the 107th World Health Organization Executive Board meeting held in Geneva between 15 and 22 January 2001.

He proposed a return to the originally ancient natural philosophy of dietetics as the good life well led, of which food and eating is one part.

[62][63] He then wrote The Fate of Nations, subtitled "Food and Nutrition Policy in the New World", in which he proposed that the pressing need now was to conserve resources and the biosphere.

[72] Brazil held the presidency of the World Federation of Public Health Associations (WFPHA) in 2009, and Cannon was a member of the Brazilian delegation to the 12th meeting in Istanbul.

[78] By 2012, the team led by Monteiro and now including Cannon, in consultation with investigators in other countries, developed the thesis into what became known as the NOVA classification.

[79] The team was in 2012 invited by the Brazilian federal Ministry of Health to draft the text of the second official national dietary guidelines.

[81] Monteiro, Cannon and many other authors have published extensively on the NOVA system and its implications for nutrition, public health, society, economics and the environment.

After graduating from Balliol, Cannon lived in the Bayswater, Hampstead and Battersea areas of London from 1961 to 1968 with his first wife Antonia and their three children, Benedict, Matthew and Lucy.