The Scientific Basis of Guideline Recommendations on Sugar Intake A Systematic Review Jennifer Erickson, RD*; Behnam Sadeghirad, PharmD, MPH*; Lyubov Lytvyn, MSc; Joanne Slavin, PhD, RD; and Bradley C. Johnston, PhD Background: The relationship between sugar and health is af- fected by energy balance, macronutrient substitutions, and diet and lifestyle patterns. Several authoritative organizations have is- sued public health guidelines addressing dietary sugars. Purpose: To systematically review guidelines on sugar intake and assess consistency of recommendations, methodological quality of guidelines, and the quality of evidence supporting each recommendation. Data Sources: MEDLINE, EMBASE, and Web of Science (1995 to September 2016); guideline registries; and gray literature (bibliographies, Google, and experts). Study Selection: Guidelines addressing sugar intake that re- ported their methods of development and were published in English between 1995 and 2016. Data Extraction: Three reviewers independently assessed guideline quality using the Appraisal of Guidelines for Research and Evaluation, 2nd edition (AGREE II), instrument. To assess ev- idence quality, articles supporting recommendations were inde- pendently reviewed and their quality was determined by using GRADE (Grading of Recommendations Assessment, Develop- ment and Evaluation) methods. Data Synthesis: The search identified 9 guidelines that offered 12 recommendations. Each of the reviewed guidelines indicated a suggested decrease in the consumption of foods containing nonintrinsic sugars. The guidelines scored poorly on AGREE II criteria, specifically in rigor of development, applicability, and editorial independence. Seven recommendations provided non- quantitative guidance; 5 recommended less than 25% to less than 5% of total calories from nonintrinsic sugars. The recom- mendations were based on various health concerns, including nutrient displacement, dental caries, and weight gain. Quality of evidence supporting recommendations was low to very low. Limitation: The authors conducted the study independent of the funding source, which is primarily supported by the food and agriculture industry. Conclusion: Guidelines on dietary sugar do not meet criteria for trustworthy recommendations and are based on low-quality ev- idence. Public health officials (when promulgating these recom- mendations) and their public audience (when considering di- etary behavior) should be aware of these limitations. Primary Funding Source: Technical Committee on Dietary Carbohydrates of the North American branch of the International Life Sciences Institute. (PROSPERO: CRD42015029182) Ann Intern Med. 2017;166:257-267. doi:10.7326/M16-2020 Annals.org For author affiliations, see end of text. This article was published at Annals.org on 20 December 2016. * Ms. Erickson and Dr. Sadeghirad contributed equally to this work. T he relationship between sugar and health is com- plex due to multiple interrelated variables, includ- ing state of energy balance, macronutrient substitu- tions, and underlying diet and lifestyle patterns (1). Existing evidence of a link between sugar intake and adverse health outcomes has been translated into di- etary guidance and recommendations for the general public by authoritative health organizations (2). Dietary guidance addresses the types of sugars, especially sources of nonintrinsic sugars, such as added sugars and free sugars (2). Added sugars consist of monosac- charides and disaccharides added during the produc- tion and preparation of foods and beverages and do not include sugars naturally found in milk, fruit, and fruit juice. Free sugars comprise sugars added to products as well as sugars naturally found in fruit, honey, and syrup (3). As research continues to add knowledge, authori- tative organizations have issued public health guidance based on the available evidence (2). Recent guidelines have included both qualitative and quantitative recom- mendations that consistently focus on limiting and re- ducing sugar consumption, especially sources of non- intrinsic sugars (2). For example, in 2015, the World Health Organization (WHO), the Scientific Advisory Committee on Nutrition (SACN), and the U.S. Depart- ment of Agriculture and U.S. Department of Health and Human Services issued public health guidelines (PHGs) with specific recommendations for dietary sugar intake (4 – 6). Each organization conducted its own review of the available evidence and published its recommenda- tions, including the scientific basis for its conclusions. These organizations have crafted different recommen- dations with regard to sugar consumption, with various rationales for limiting intake. When respected organizations issue conflicting recommendations, it can result in confusion and raises concern about the quality of the guidelines and the un- derlying evidence. We conducted a systematic survey and critical appraisal of authoritative PHGs, including an assessment of the quality of evidence supporting recommendations for dietary sugar intake. See also: Editorial comment ......................... 305 Web-Only CME quiz Annals of Internal Medicine REVIEW © 2017 American College of Physicians 257 Downloaded From: http://annals.org/ on 09/22/2017