Delia Smith is among a number of celebrities being criticised by a charity for offering health tips on subjects they know little about.
Sense About Science said the public should be wary of celebrity claims about health which may be based on limited knowledge.
In The Celebrities and Science Review 2008 the group targeted food gurus Delia Smith and the so-called domestic goddess Nigella Lawson for their lack of understanding about food issues.
Delia was pulled up for her lack of understanding of obesity.
The cook said: "That's what causes obesity. It's addiction. After six weeks (without sugar) everything will taste sweet ... because you will have got your palate back to what nature created.
"We could cure the nation if we cut down sugar addiction."
But Lisa Miles, senior nutrition scientist at the British Nutrition Foundation, said: "Delia, you'll never get rid of sugar from the diet, nor would you want to as you consume sugars naturally in many foods which provide us with important nutrients. The causes of obesity are much more complex."
The review criticised Nigella for claiming mind meals "can help you feel different about life".