The agency’s Media Consumption Forecast reported people will spend an average of 492 minutes a day consuming media this year – up 1.4 per cent from 485 minutes a day in 2014.
Jonathan Barnard, the head of forecasting at ZenithOptimedia, said: "The average person already spends half their waking life consuming media.
"But people around the world are clearly hungry for even more opportunities to discover information, enjoy information, enjoy entertainment and communicate with each other, and new technology is supplying these opportunities."
The report forecasts internet consumption will grow by 9.8 per cent a year between 2014 and 2017 to reach 144.8 minutes a day.
Internet use a share of overall media consumption rose from 12.9 per cent in 2010 to 22.6 per cent in 2014. It will grow to 28.6 per cent of the total in 2017.
Apart from outdoor, the growth in internet use means traditional media i.e. newspapers, magazines, television, radio and cinema, fell between 2010 and 2014, with this decline expected to continue.
The average time spent reading newspapers fell by 25.6 per cent, with magazine reading time declining by 19 per cent between 2010 and 2014.
Television consumption dropped by 6 per cent over the same period.
But the report does not count reading newspapers on digital devices, or watching television via the internet, which are instead listed as "internet" consumption.
Lindsey Clay, the chief executive of Thinkbox, the marketing body for commercial TV, said: "We welcome Zenith’s positivity about TV’s continued strength. However it is frustrating when ‘the internet’ is positioned as a medium having a detrimental effect on other media.
"There are many factors that affect media consumption – you can’t put every change down to the internet.
‘But more importantly the internet is not a medium; it is a technology which delivers loads of things – banking, shopping, (re)searching… and lots of different media. You can’t lump all this activity together. If you do, you lose sight of how things are changing as media are consumed across different platforms."
The report surveys the changing patterns of media consumption in 65 countries around the world from 2014 to 2017.