The World Health Organization issued new guidelines this week calling for adults and children to limit consumption of added sugar to less than 10 percent of calories.

The United Nations’ public health arm recommended that people reduce their daily intake of sugars to 6 to 12 teaspoons per day. It added that curtailing sugar to less than 5 percent of calories consumed “would provide additional health benefits” and help prevent diseases such as diabetes and heart disease.

The guidelines apply to foods and beverages with added sugars, not to those with naturally occurring sugars such as fruits, vegetables and milk.

“We have solid evidence that keeping intake of free [added] sugars to less than 10 percent of total energy intake reduces the risk of overweight, obesity and tooth decay,” Francesco Branca, the director of the WHO’s department of nutrition for health and development, said in a statement. “Making policy changes to support this will be key if countries are to live up to their commitments to reduce the burden of non-communicable diseases.”

The recommendations, the WHO said, are based on evidence that adults who eat less sugar tend to weigh less and that children who drink the most sugar-sweetened beverages are more likely to be obese than children who drink less.

The WHO’s guidelines point out that processed foods and beverages that many people don’t think of as sweet have “hidden” added sugars. One tablespoon of ketchup, for example, has about a teaspoon of added sugar. A can of sugar-sweetened soda has about 10 teaspoons.

Experts have warned that eating excessive amounts of sugar increases the risk of obesity-related diseases such as heart disease, diabetes and cancer. 

To meet the WHO's new guidelines, Americans and Europeans would have cut their average sugar intake by about two-thirds. Sugar accounts for about 13 percent of calories in the typical U.S. diet. And in some European countries such as Spain and the United Kingdom, it’s responsible for 16 or 17 percent, the WHO said, with children often consuming even more.