Trying to eat light and cut back on sugar? Then watch what you drink. Soft drinks, juices, flavoured mineral waters, fruit-based drinks and sports drinks are the major source of sugar, according to CSIRO who analysed the Australian diet for sugar intake. Collectively these drinks supply 30 per cent of the added sugar adults consume but as much as 47 per cent in teenage boys who have a sweet tooth and are the biggest consumers of sugar.