Is that why they don't fry their French fries in tallow anymore?
No, they got sued because they added "beef flavoring" which were
hydrolyzed wheat and hydrolyzed milk. During the hydrolyzing process water breaks down the proteins in these ingredients to create the "beef flavor". The lawsuit was for mislabeling their fries as vegetarian even though the beef flavoring wasn't actually beef fat but the milk from dairy cattle.
McDonalds switched from beef tallow to vegetable cooking oil because of the misguided science that animal fat where all of a sudden the cause of heart disease so in accordance to public pressure they originally switched to a vegetable oil that was a
"partially hydrogenated seed oil" which contained a very high amount of unnatural trans fats which were directly seen as causative to the increase of heart disease, so they were basically adding to the problem without knowing, or they did know but public opinion and pressure would not work in their favor, we'll never know I guess.
They later switched after the law insisted that trans fats be eliminated from the food supply and went with a "
high oleic canola oil blend" which was bred into existing canola plants to produce an oil with a higher monounsaturated fat content as opposed to the regular canola oil. Even this process doesn't eliminate all the trans fats and some trace trans fats are actually generated just from the refining process but as far as percentage of a serving it shows less than 0.5 grams which legally is acceptable and can actually be advertised as "0 trans fats", but they can never say "No trans fats".
Personally I never believed in this "dogma" and have used beef tallow for all my deep frying and I don't use seed oils of any kind in any of my cooking but do use fruit oils like olive oil, avocado oil and coconut oil where these oil are much less susceptible to the oxidation that takes place with polyunsaturated fats which for the most part are seed oils. The problem with seed oil consumption is it mucks with our LDL cholesterol making each LDL particle smaller and much more atherogenic and it increases low grade chronic inflammation where beef tallow does the opposite as does the fruit oils. Just thought I'd add my opinion.
Personally I don't save beef drippings and would rather use fresh or another fat like olive oil, butter, duck fat etc but do save bacon fat and chicken schmaltz for the flavor they bring which are legendary imo.
People always ask why my fries taste so good and i say it's because I don't use oils that were originally designed to lubricate machinery.
