'They be lying to us': McDonald's worker posts TikTok video showing all their cups hold the same amount - but he's accused of faking it

TikTok users have been left puzzled after a McDonald's worker posted a video claiming that all their sizes of drink cups hold exactly the same amount of beverage.

The clip, which has been viewed more than 1.6 million times shows an employee from the fast food chain pouring a Coke into a small 16oz McDonald's cup, before tipping the entire contents into a 21oz medium size cup and then transferring the drink into a large 30oz cup.

Each time, the drink appears to fill the cup up to the top giving the impression to the viewer that the containers all seem to hold equal amounts despite their obvious variation in size.

'They do be lying to us doe,' worker @mykah.mykah captioned the video.

But many viewers were not fooled by the camera trickery.

So far, the video has more than 12,000 comments, mainly from skeptics who believe that some amount of the drink had already been poured into the cups before the stunt was filmed, but carefully hidden by the camera angle.

Crucially, the video never reveals the bottom of the cup which would clearly show some liquid had already been sitting inside.

'That's what happens when you fill up each of the cups slightly and then pour more in,' one person wrote, while another agreed adding, 'You could at least make it less obvious that you filled the cups.'

But there are some users who appear to be playing along, claiming the video is the real deal.

'I worked at McDonald's and this is true,' a former employee said. 'Always say no ice or ice on the side (in another cup) and only order smalls, NEVER medium.'

Another user joked that it didn't matter whether the claim is true or not.

'Either way, y'all are just gonna fill the whole cup with ice and leave no room for the drink itself,' they wrote.

'Now pour the big one into the small one,' challenged one user.

'So, nobody know he put some coke in the cups before the fill up?' wrote another.