"The [Joint WHO/FAO Expert] Consultation recognized that a population goal for free sugars of less than 10% of total energy is controversial [with respect of the prevention of obesity]. However, the Consultation considered that the studies showing no effect of free sugars on excess weight have limitations."
See also: Comments on the draft report of the joint WHO/FAO expert consultation on diet, nutrition and the prevention of chronic diseases
www.who.int/dietphysicalactivity/publications/