Nutritional guidelines restricting sugar intake are not based on reliable science, suggests a review published in Annals of Internal Medicine. The quality of available evidence to link sugar with health outcomes is generally rated as low to very low. Public health officials and consumers should be aware of these limitations when considering recommendations on dietary sugar.
The relationship between sugar intake and health is complex and is influenced by many variables. Based on available evidence, several authoritative health organizations, including the World Health Organization, have issued differing public health guidelines on sugar consumption. When respected organizations issue conflicting recommendations, it can result in confusion and raises concern about the quality of the guidelines and underlying evidence.
Researchers conducted a systematic review of nine authoritative guidelines on sugar intake to determine the consistency of recommendations, methodological quality of guidelines, and the quality of evidence supporting each recommendation. Guideline quality was rated using the Appraisal of Guidelines for Research and Evaluation 2nd edition (AGREE II) instrument.
To assess evidence quality, articles supporting recommendations were independently reviewed and rated using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methods. The researchers concluded that guidelines on dietary sugar are based on low-quality evidence and, therefore, do not meet criteria for trustworthy recommendations. These findings suggest that the development of trustworthy guidelines on dietary sugar requires improvement.
The authors of an accompanying editorial suggest that the public consider the funding source and methods of the review before accepting the authors’ conclusions. They note that the review was funded by the North American branch of the International Life Sciences Institute, a trade group representing several big companies in the food and beverage industry, including The Coca-Cola Company, The Hershey Company, and Mars, Inc..