A man claiming to be a Subway employee has divulged the fast food chain's secrets — and some of them might put you off your lunch.

The worker, who claims to be a shift manager at a UK franchise store, took to Reddit and asked social media users to quiz him about the sandwich giant.

"Which items would you recommend one avoid and which would you say are highest quality/safest/best prepared?" asked Mistakescostextra.

Using the acronym SubwayworkerUK, the alleged employee warned fans to "avoid chipotle chicken and teriyaki chicken."

He continued: "Why? Chicken is given a two-day shelf life, once in the counter. However, these two [sandwiches] bypass this and get four days, and can get a little stinky.

"I'd recommend anything else, Subway (at least my Subway) is very strict on quality control and dates. Steak is probably the freshest, and safest."

G-o-dude asked: "What's the best bang for the buck sub?"

The unidentified shift manager, who made it clear he was not speaking on behalf of his employer, replied: "Meatball Marinara, Chipotle Chicken, Tikka Chicken, Spicy Italian, and BMT."

He explained these sandwiches are all $4 or $6.50 for a footlong with a drink.

He also told Subway customers that sandwiches are 20 percent off between 7 p.m. and 9 p.m.

In the eye-opening thread, the employee also revealed how to get more sandwich for your money.

"Subway Footlong" is actually a trademark of Subway and is just the name of the sandwich, most measure in at 12.1 inches long, the worker revealed.

He added: "In regards to shrinkage, minor shrinkage occurs when the bread is baked.

"We have a measuring ruler built into the counter (normally only used for kids packs, 4-inch sandwiches), and our bread seems to always be around 12.1 inches.

"Here's a little tip – if you want a footlong, try flatbread. The way flatbread is made and prepared we give you 14 inches."

A Subway brand spokesperson responded to the allegations and told The Sun Online: "All Subway stores are independently owned and operated by franchisees.

"All stores have very strict procedures in place to ensure products are served safely and to customers' satisfaction and all suppliers are required to meet our high standards of food safety and product integrity."

The anonymous manager also revealed how customers can recreate the distinctive Subway taste at home.

"Subway just has that unique subway taste and smell," he said.

"Why don't you go into Subway and buy just a stick of bread, try making your sandwich with that!"

The employee also revealed the food giant's secret menu option of "frozen cookie dough."

Mrnoor asked: "Can you say how to make the honey mustard and sweet onion sauces at home? Also, what's the secret to making them cookies so doughie [sic]!?"

The worker revealed: "I'm sure you can find some replica recipes online. We don't make the sauces in store.

"Our cookies are frozen, and we have to cook them at 160 degrees for 11 minutes.

"I take my cookies out 2 minutes early because I like them gooey. If you go into a Subway, try asking for frozen cookie dough!"

The employee said the store sells more salad bowls than sandwiches, and his favorite is a "6-inch hearty Italian, meatball sauce, cheese, toasted. With a ton of salad and southwest sauce."

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