National Obesity Forum (NOF) deputy chairwoman Deborah Cook, a diabetes nurse, and Dr Jen Nash, a clinical psychologist, quit the board as a result of the 23 May report, Eat Fat, Cut The Carbs And Avoid Snacking To Reverse Obesity And Type 2 Diabetes, a spokesman said.
Their departure follows those of clinical director Dr Matt Capehorn and consultant obstetrician and gynaecologist Sangeeta Agnihotri on Thursday.
In the damning report, which accuses major public health bodies of colluding with the food industry, the NOF and the Public Health Collaboration called for a “major overhaul” of current dietary guidelines.
The report, which has caused a huge backlash among the scientific community, also argued that saturated fat does not cause heart disease while full fat dairy foods can actually protect the heart.
NOF chairman Professor David Haslam said he was “not stepping back on the content” of the report, which has been backed by global experts, but said the way the message was delivered may have been a problem.
He said: “They [the NOF]do not disagree with the content of the report, just the way in which the report was published without their final say on it. Other board members feel, quite rightly, that, had they known this report would be going around the planet, they would have wanted a more emphatic input in it. I agree and apologise.”
The NOF is a charity set up in 2000 to promote ways to tackle obesity through “achievable and manageable lifestyle changes”.
An NOF spokesman said: “The publication went out without their knowledge or having seen a draft of anything. In a democratic organisation that is not what you do. It has caused a huge amount of problems. They feel they were not consulted or shown any of the drafts of the document.”
The report also said sugar should be avoided, people should stop counting calories and the idea exercise can help you “outrun a bad diet” is a myth. Instead, a diet low in refined carbohydrates but high in healthy fats is “an effective and safe approach for preventing weight gain and aiding weight loss”.