WHO 10% Free Sugars Guideline Based on Tooth Decay, not Obesity; Unchanged from the March 2014 Draft Guideline

The World Health Organization (WHO) final 10% guideline on free sugars intake continues to be based on evidence related to tooth decay, not overweight or obesity. The final guideline is the same as proposed in their draft guideline and the WHO has clarified that this is "based on moderate quality evidence from observational studies of dental caries"¹. 

The WHO also indicates that the "conditional recommendation" to further limit free sugars intake to less than 5% of total calories is based on "very low quality evidence from ecological studies" also in relation to dental caries. 

Neither of the quantitative targets on free sugars intake were established based on WHO reviewed evidence in relation to obesity. In fact, the systematic review commissioned by the WHO on sugars and body weight concluded that changes in body weight are directly associated with changes in caloric intake and that there is no unique effect of sugars compared to other carbohydrates on obesity². The updated WHO advice for an overall healthy diet states that "energy intake (calories) should balance energy expenditure"³. 

Dental caries (tooth decay) is one of the most prevalent chronic conditions globally. In Canada and other developed countries, fluoride and tooth brushing are recognized as the primary strategies for tooth decay prevention⁴. The Canadian Sugar Institute (CSI) Nutrition Information Service recognizes the importance of reducing tooth decay globally and supports a review of the applicability of the WHO guidance to Canadians. The WHO's targets for free sugars intake do not account for the large body of research showing that frequent consumption of all fermentable carbohydrates, which include not only sugars but also starches, contributes to tooth decay⁵.

Globally, dietary sugars consumption is declining or stable in many developed countries⁶.  Added sugars consumption in Canada has been declining over the past four decades and the current average consumption of added sugars in Canada is estimated to be about 11% of total caloric intake⁷. 

The Institute of Medicine (IOM) Dietary Reference Intake (DRI) report forms the basis of dietary advice in Canada and the United States and found insufficient evidence to set an upper limit on added sugars in relation to dental caries, behavior, cancer, obesity, and hyperlipidemia. A maximum intake of 25% or less of energy from added sugars is suggested based on the decreased intake of some micronutrients in American subpopulations exceeding this level⁵.

Obesity is a complex, multifactorial condition and solutions to the prevention of obesity require public health approaches that address the wide range of behavioral and societal factors that play a role. All non-fibre carbohydrates including sugars, provide energy measured as 4 calories per gram. Research shows that sugars are not unique in their contribution to calories or body weight compared to other energy sources^2,8; nor does the amount of sugars in the diet predict the healthfulness of a diet⁹. Nutrition experts agree that isolating or restricting a single food or nutrient such as sugar is unlikely to be an effective approach in addressing complex public health problems such as obesity^10,11. Rather, for the general Canadian population, focusing on balanced healthy eating according to Canada's Food Guide, managing portion sizes, moderation in overall food intake, and engaging in regular physical activity are key steps in achieving and maintaining a healthy body weight. 

For more information, also see CSI Nutrition Information Service Review of WHO "Draft guidelines on free sugars released for public consultation, 5 March 2014"

The Canadian Sugar Institute (CSI) maintains a Nutrition Information Service, which monitors the scientific literature and reports, and interprets the findings to provide Canadian health professionals, educators, and consumers with current scientific information on sugars and health. 

¹ http://www.who.int/nutrition/publications/guidelines/sugars_intake/en/

² Te Morenga L, Mallard S, Mann J. Dietary sugars and body weight: Systematic review and meta-analyses of randomised controlled trials and cohort studies. British Medical Journal 2013;346:e7492.

³ http://www.who.int/mediacentre/factsheets/fs394/en/

⁴ Jones S, Burt BA, Petersen PE, Lennon MA. The effective use of fluorides in public health. Bulletin of the World Health Organization. 2005;83:670-676. 

⁵ Food and Nutrition Board, Institute of Medicine, National Academy of Sciences. Dietary reference intakes for energy, carbohydrates, fiber, fat, protein and amino acids. National Academic Press. Washington, 2005. 

⁶ Wittekind A, Walton J. Worldwide trends in dietary sugars intake. Nutrition Research Review. 2014;27"330-345.

⁷ Brisbois TD, Marsden SL, Anderson GH, Sievenpiper JL. Estimated intakes and sources of total and added sugars in the Canadian diet. Nutrients. 2014 May 8;6(5):1899-912. 

⁸ Langlois K, Garriguet D. Diet composition and obesity among Canadian adults. Statistics Canada Health Report 2009.

⁹ Forshee RA, Storey ML. Controversy and statistical issues in the use of nutrient densities in assessing diet quality. J Nutr. 2004 Oct;134(10):2733-2737. 

¹⁰ Wolever TMS & Sievenpiper JL. Revised food labeling in North America: the blind leading the blind? European Journal of Clinical Nutrition 2014;68:1275-1276. 

¹¹ Slavin J. Two more pieces to the 1000-piece carbohydrate puzzle. American Journal of Clinical Nutrition 2014;100:4-5.