For years, McDonald’s fries ruled the world. They were golden, crispy, salty, and delicious. People called them the best fries ever made. But then something changed. Around the 1990s, fans noticed the fries didn’t taste the same anymore.

What happened?

Let’s dive into the real story of why McDonald’s fries lost their magic—and how the changes didn’t make them healthier. In fact, for a while, they actually made them worse.

Before 1990, McDonald’s cooked their fries in a special mix: 7% cottonseed oil and 93% beef tallow. That’s a fancy way of saying animal fat. This gave the fries a rich, savory flavor you couldn’t find anywhere else.

Why did they use beef fat? Because Ray Kroc, the man who built the McDonald’s empire, wanted fries to taste like the original McDonald brothers’ version. He nailed it.

But not everyone loved the fat.

Phil Sokolof wasn’t a doctor. He wasn’t a scientist. But he was a wealthy businessman from Nebraska who had a heart attack. After that, he became a full-time food activist. Think of him like an early version of today’s online influencers—lots of passion, not much science.

Sokolof spent millions on full-page newspaper ads. His messages sounded scary:

It worked. The public panicked. McDonald’s gave in.

In 1990, the company switched from beef fat to 100% vegetable oil.

At first, this seemed like a healthy change. But here’s what they didn’t tell you: the new vegetable oil was partially hydrogenated, meaning it was full of trans fats—the most dangerous kind of fat for your heart.

Trans fats increase your bad cholesterol (LDL) and lower your good cholesterol (HDL). They raise your risk of heart disease way more than saturated fat.

In trying to remove one bad fat, McDonald’s accidentally replaced it with something even worse. FDA, 2015.

They finally banned trans fats in the U.S. in 2018—but for almost 20 years, those “healthier” fries actually hurt people’s hearts more than the original version ever did.

Customers missed the old flavor. So what did McDonald’s do? They added “natural beef flavoring” to the vegetable oil. Yep, they removed the beef fat… and then added beef flavoring back in.

This confused people. Some vegetarians and Hindus believed the fries were plant-based. They weren’t, leading to lawsuits and even more public confusion.

In the United Kingdom, McDonald’s fries are really vegan. But in the United States, that natural beef flavor still makes them off-limits to some groups.

Now fast-forward to today. Steak 'n Shake announced they were bringing back beef tallow for their fries, just like McDonald’s used to. This move caught the attention of RFK Jr., a well-known figure in politics and food activism.

He praised the change. But here’s the problem: RFK Jr. isn’t a doctor. He’s not a nutritionist. In fact, he’s never taken a college-level science course.

RFK Jr has a long history of pushing food myths and anti-science messages, just like early...