The Dutch tech site Tweakers.net also found this in their tests [1].
They found that battery life was degraded mostly in standby mode (with iOS7 losing 12% of battery after 16 hours of standby time, compared to 7% on iOS 6.1.4).
With a more active usage pattern, they found the differences were smaller: their iPhone 5 running iOS 7 lasted 16 hours, compared to 17 hours on iOS 6.1.4.
This would suggest the increased consumption is more likely to come from background stuff than from visual UI effects.
They found that battery life was degraded mostly in standby mode (with iOS7 losing 12% of battery after 16 hours of standby time, compared to 7% on iOS 6.1.4).
With a more active usage pattern, they found the differences were smaller: their iPhone 5 running iOS 7 lasted 16 hours, compared to 17 hours on iOS 6.1.4.
This would suggest the increased consumption is more likely to come from background stuff than from visual UI effects.
[1] http://tweakers.net/nieuws/91361/accu-iphone-5-sneller-leeg-... (Dutch)