If you drink a single can of pop a day, you're consuming too much sugar.
That is the message from the World Health Organization, which on Wednesday unveiled new draft guidelines that say reducing sugar consumption to just 5 per cent of calories is the best way to achieve "additional health benefits." The global public-health agency also renewed its call for governments around the world to recommend a firm limit of no more than 10 per cent of calories per day from sugar, a call Ottawa is so far refusing to heed.
The Canadian government is already under increasing pressure from health organizations to set guidelines on sugar consumption following the release of a study published last month in the journal JAMA Internal Medicine that established a link between high sugar intake and heart disease deaths.
Asked whether Canada would consider adopting the WHO's guidelines on sugar, Health Minister Rona Ambrose's office replied with an e-mailed statement touting the government's ongoing consultations on reforming the nutrition labels on packaged foods.
In a separate statement, Health Canada said it was reviewing the WHO's draft recommendation.
The WHO's move to update its dietary advice reflects the evolution of the science on sugar, which now more strongly indicates that sugar leads to obesity and tooth decay.
The proposal is likely to elicit a strong reaction from the packaged food industry – lobbyists convinced the U.S. government to threaten to withdraw funding for the WHO when it established the 10-per-cent threshold more than a decade ago – and possibly from health advocates who would prefer the agency definitively lower the limit to 5 per cent.
"There'll be a lot of health advocates and people who believe that sugar is really the dominant evil of the moment that say [the WHO] didn't go low enough," said John Sievenpiper, a scientist at the Li Ka Shing Knowledge Institute at St. Michael's Hospital in Toronto who also cautioned that sugar cannot be considered in isolation from total calories.
Lowering the limit is not out of the question down the road, said Francesco Branca, the WHO's director of nutrition for health and development, noting the "evidence [against sugar] is expanding by the day."
"This is a changing scenario," he told a news conference in Geneva. "Even the 5 per cent [goal], which at the moment is our ideal and is a conditional recommendation, might in the future be reconsidered in the light of the new evidence."
The proposed guidelines apply to so-called free sugars, which include sugar that manufacturers, cooks and consumers add to food, as well as honey, syrup, fruit juices and fruit concentrates. They do not apply to sugars that occur naturally in whole fruits, vegetables and unsweetened dairy products.
To meet the 5-per-cent target, an adult of a healthy weight would need to eat fewer than six teaspoons or 25 grams of sugar a day. That means one can of regular pop, which can contain 40 grams of sugar, would exceed the target. Even seemingly healthier foods can add up quickly – a sugar-sweetened yogurt, a bowl of cereal and a granola bar eaten over the course of a day would likely push one over the 5-per-cent mark.
"Five per cent is a very low target," said Sandra Marsden, president of the Canadian Sugar Institute, an industry group. "I haven't seen the evidence in the meta-analyses that were provided [by the WHO] that would support Canadians straying from our current dietary guidelines."
The new WHO draft guideline, which is up for public consultation until the end of this month, is anchored in two systemic reviews of published studies on sugar – one focused on weight, the other on tooth decay. The latter provided the strongest evidence for suggesting an "ideal" target of 5 per cent of sugar a day.
The WHO did not take into account emerging evidence that excess sugar leads to heart disease, including a landmark study published last month that found consuming more than a quarter of daily calories in sugar nearly tripled the risk of heart attack.
Health Canada relies on the U.S. Institute of Medicine (IOM) to guide its dietary reference intakes for vitamins, minerals and macronutrients – all of which underpin the vague advice in Canada's Food Guide to eat less sugar.
The IOM recommends limiting added sugars to no more than 25 per cent of daily calories in an effort to keep sweets from crowding out healthier fare.
However, when the IOM, one of the national academies that advise the U.S. government, last looked at sugar in 2002, it concluded there were "insufficient data" to establish an official upper limit.