Sir, I was saddened to find that the red herring of intrinsic and extrinsic sugars and their comparative cariogenicity appeared once again in the paper A comparison of the nutritional knowledge... (BDJ 2011; 210: 33–38).

The report of the Committee on Medical Aspects of Food Policy, 'Dietary sugars and human disease', has been responsible for much confusion in the delivery of diet advice since it was published in 1989. The myth that intrinsic sugars are somehow less potentially damaging to the dentition than extrinsic sugars was debunked by I. Hussein, M. A. Pollard and M. E. J. Curzon in A comparison of the effects of some extrinsic and intrinsic sugars on dental plaque pH (Int J Paediatr Dent 1996; 6: 81–86). The most sensible advice to give patients is to avoid eating between meals as all snacking has the potential to cause either caries or obesity.

The lead author of the article, Dr Maria Morgan, responds: I would like to thank the correspondent for their interest in the article. But I and my colleagues would like to emphasise that we referred to the COMA report 'Dietary sugars and human disease' as part of the guidelines that are in current use. It was not our intention to focus in on non-milk extrinsic sugars and intrinsic sugars per se. We would agree with what the correspondent says about snacking, that for the general population snacking should be kept to a minimum, but there will be some instances where smaller frequent meals are indicated for specific nutritional concerns. I hope this clarifies things.