Barry Popkin, a professor of Nutrition at the University of North Carolina, and a nutrition expert who has advised the U.S. government and health policy makers around the world, says sugary drinks should be taxed. Popkin told Reuters that  the epidemic of obesity and weight gain sweeping the globe could be slowed dramatically by limiting the intake of sugary drinks since, depending on the country you live in, 10 to 25 percent of all calories consumed are in sugary or caloric beverages. Reviving a taste for water could cut between 300 and 600 calories a day from the diet of an average American or Mexican, and almost as much from the intake of many Europeans.