A row has erupted about links between the sugar industry and scientists who advise government on obesity.
The argument was sparked by a report on the issue in the British Medical Journal.
It claims Prof Susan Jebb - the government's obesity tsar, a University of Oxford academic and an expert in a recent three-part BBC documentary series on obesity - has attracted more than £1.3m of industry funding.
This includes money from Coca-Cola, Unilever and Cereal Partners.
The article says members of a government advisory panel - the Scientific Advisory Committee on Nutrition (SACN) - are supported by companies such as PepsiCo, Mars and Nestle.
It also claims that of the 40 scientists affiliated with SACN between 2001 and 2012, just 13 had no connections to the sugar industry.
BMJ editor-in-chief Fiona Godlee said the investigation showed there was a "network of relationships between key public health experts and the sugar industry".
She said "these sorts of links create bias" and "weaken public health efforts to tackle the harmful effects of sugar on the diet".
Prof Simon Capewell, from the University of Liverpool and an adviser for the group Action on Sugar, told the BBC: "I was shocked, quite honestly; this is heart-breaking news and basically it appears a lot of people have been seriously misled."
He said there would be an "inherent conflict of interest" between profits and public health.
"It's like putting Dracula in charge of the blood bank," he concluded.