Taking to Reddit, the ex-employee who uses the name JB4T5gamemusic shared their insider tips.

They claimed: "I worked in fast food for a decade (McDonald's) and quit about seven years ago. Here are a few insights/ secrets.”

The post highlighted that while it's common knowledge that McDonald's pre-cooks some items and keeps them warm, this means they're not exactly fresh when served.

The user explained that the fast service is credited to keeping cooked items in the warming cabinets “for a while”.

While it doesn’t hinder the taste, McDonald's fans who want to get the freshest possible meal can use the former employee’s clever hack to do so.

In the Reddit post, the fast-food chain worker claimed customers should order meat and fries without salt.

The logic to this simple swap is that McDonald's staff “have to salt and season every piece of beef that crosses the grill and every fry that takes a dunk in the fryer”.

Submitting a special request on your order means the food must be cooked fresh to ensure it’s free from added salt.

‌According to the ex-employee, doing this means the food also has to be cooked on a clean grill.

The revelation is aptly timed, as the fast-food chain recently made some major changes to the cooking process of their menu items.

Changes were made to improve “all the elements customers enjoy most” - from soft burger buns to the diced onions.

Restaurants across the UK now put onions on top of each patty while they are cooking on the grill for extra flavour, while also changing the sear of the beef patties among other things.

When it comes to the signature McDonald’s fries, the chain makes a promise to customers that they are served hot.

It claimed: "When our suppliers partially fry our cut potatoes, they use an oil blend that contains beef flavouring... The fries are cooked in our kitchens, seasoned with salt, and served hot to you."

An ex-employee of the famous American fast-food chain offered another handy tidbit for dedicated fry-lovers.

They claimed: "If fries are over seven minutes old out of the fryer, they must be discarded. This is why if you wait till you get home to eat them, they suck unless you live close."