Lovers of the fast food chain will be awarded £100 if they can eat a meal big enough to feed a family of four.
The Big Mac challenge is not affiliated with the restaurant, but has been created by apparent superfans of the chain.
According their Facebook page, their goal is to “find the person that can actually do this.”
The group was set up in 2005, but they have yet to find a winner because, they say, “as soon as someone wins, and we have hard, undisputable video evidence, this page will be shut”.
The challenge requires someone to eat four Big Macs, four large fries and four large milkshakes of any flavour in 60 minutes.
Shockingly, this amounts to 5,740 calories and 226.8g fat in one sitting.
All food must be held down for 30 minutes after swallowing the final mouthful.
And every single part must be consumed – so any food that falls out of the packaging must also be swallowed down.
Pickles, however, are optional – which is lucky, as they can be considered a controversial part of the burger.
Food is purchased by organisers, and £100 will be awarded to whoever completed the challenge and provides video evidence.
Those who don’t complete the challenge must reimburse event holders for the meals, and buy them three pints of beer each.
Organisers have no expectation of anyone being able to complete the challenge.
They write on their page: “Fair warning: If you think you can do this, you’re wrong. But for some reason people keep on trying. And we’ll keep drinking their beer.”
And making sure to cover their backs for any illness, they write: “The organisers and host venue take no responsibility for any risks undertaken or damages caused to your person, your mental state, you not being able to show up at work for the next two days because of your smell, your personal/professional reputation or short to long term health risks. You will be filmed and it will be posted here.
“It is not a good idea to attempt this as it is physically impossible, regardless of your preparations, strategy, size or weight. Believe us, we’ve seen it all. “
Whilst McDonald’s don’t have anything to do with the Big Mac challenge, they are giving something away to loyal customers – those who purchase their new Signature Collection will get something special with it.