A secret lurking in some fast-food fish sandwiches could compromise no-meat diets during Lent

Get the Full StoryLent starts Wednesday which means that many Catholics will be abstaining from eating meat on Fridays.

Business Insider has confirmed that several fast-food restaurants are using beef oil to cook seemingly Lent-friendly products such as fish and fries.

McDonald's has been sued for using this oil in the past.

Beware of fast food this Lenten.See the rest of the story at Business InsiderNOW WATCH: What 'Dilly Dilly' means and how Bud Light came up with its viral campaignSee Also:Amazon's Whole Foods delivery service is off to a roaring start and it's a huge threat to InstacartPepsi is investing in a 1 billion part of its business to avoid the retail apocalypse that wrecked Sears and Macy'sShoppers are dropping hundreds of dollars on 'ugly' clothes here are the worst examplesSEE ALSO: We tried the fried fish sandwiches from the biggest names in fast-food and the winner is clear