Sara says her breast cancer tumour disappeared after she started a strict eating regime.

"I didn't do surgery, I didn't do chemotherapy, I didn't do radiation," she tells the camera. "I'd walk into the doctor's office and they'd say, oh, our miracle patient has arrived. And that was very disturbing to me. I didn't think there was anything miracle about what was happening. I thought it was hard science."

Dr Eugene Fine, a clinical professor at the Albert Einstein College of Medicine, is then interviewed in an apparent bid to support Sara's claims.

"Most cancers are treated by cocktails of drugs which fail," he says in the documentary. "Cancer cells rely on glucose as a kind of fuel. That then could then lend itself to a metabolic approach which targets just that. I don't know that's going to be the case in most cancers, but it still doesn't stop me from being optimistic about using the idea of diet as an adjunct."

Dr Fine told Fairfax Media he wishes he had expressed himself more clearly. While he didn't suggest people should shun medical treatment, he said in hindsight he should have been more explicit about the lack of scientific evidence to support the ketogenic diet.

"I try to be clear when I talk about ketogenic diets and cancer but it's hard sometimes and I guess I don't always succeed," he said.

"The short story is simple. The data on KD [the ketogenic diet] and cancer is very sparse. Therefore there is no medical justification at this time to scuttle standard therapies for a KD. I get calls from patients on the same issue."

While Dr Fine didn't accuse the documentary-makers of taking his comments out of context, the Australian medical community has been less forgiving. One scientist told Fairfax Media The Magic Pill was "really slippery" and "disingenuous".

"The overwhelming take-home message most will hear is that diet can cure cancer, but if you were to go back over the transcript they have snuck in a few words to cover themselves," he said.

Evans maintains the documentary isn't dangerous or misleading.

"We state that anyone wishing to know more should work with their health professional," he said.

Companies long-associated with the celebrity chef have stood by him following the uproar surrounding the documentary. A spokeswoman for the Seven Network said Evans was a "high-valued member of the My Kitchen Rules family".

"His genuine passion for food and healthy living is a sincere belief and evident in everything he undertakes," she said. "Pete's perfectly qualified for the work he does on MKR."