Restaurant manager Mr Liu shows the narrow metal bars that serve as a gate to the restaurant
A restaurant in east China is offering discounts to customers if they can squeeze through a gate made of narrow metal bars.
The owner of the eatery, Zhao Lang, claimed that the promotion campaign serves as a reminder for people to watch their diet.
The restaurant in Jinan city offers customers free food and beer - if they can enter the eatery by fitting through a gap that is only 15cm wide.
A girl attempts to squeeze through the narrowest bar at the restaurant in Shandong province
A sign marking the width of the bars determines the different types of discounts.
Inspired by similar challenges trending online recently, Mr Zhao intended the campaign as an entertaining challenge as well as a warning to those who are considered 'overweight'.
'So many people have told me that they've failed losing weight - just because they can't quit drinking beer,' he said.
'Maybe this could serve as a reminder to them to keep an eye on their diet.'
If a person can fit through the smallest gap, he or she can enjoy a free meal and free drinks for the entire table.
The restaurant offers discounts to customers who are 'slim' enough to fit through the bars
The next level of difficulty is at 18cm - the successful contender will win five beers.
Customers who can fit through the third gap - at 25cm - will be given one free beer.
A customer tries his luck and squeezes through the metal bars in an attempt to win a discount
The next pair of bars, with a width of 30cm, offers no discount but a message for those who can fit through: 'Your figure is just average - you shouldn't ask for more.'
The last pair of bars - which are 'exceptionally wide' according to owner Zhao Lang - poses a question to the customer: 'Are you sure you should be drinking beer?'
The restaurant owner hopes the campaign can remind people to keep an eye on their diet
'At least one person can make it through the narrowest set of bars every day,' Mr Zhao said. 'They are all female customers.'
As for the next level of difficulty, 20 people have managed to squeeze through so far.
Mr Zhao said the promotion campaign drew crowds lining up to do the 'metal gate challenge'.
Opened in 2016, the restaurant in Shandong province is known for Mr Zhao's own creation of the popular spicy crayfish dish, made with Chinese peppers, garlic and chillies, as well as other big-portioned seafood dishes.