Studies show that global sugar consumption has risen dramatically from 11 million tons in 1900 to about 145 million tons today.
VOA: standard.2010.04.25
The reliance on self-reporting weight, height, activity, and soda consumption in some studies rather than independent measuring and verification might confound their reliability, as might small sample sizes.
The report justifies the tax with the same old mantra that obesity is increasing, soda consumption is increasing, government studies speculate that increasing the cost of sugary drinks would lead to a reduction in overweight, etc.