EAST LANSING - This is a story of man versus McChicken, of human will and stomach capacity pitted against fried chicken, lettuce, mayonnaise and perfectly toasty buns.

Derek Metcalf, a senior at Michigan State University, saw a challenge posted on Snapchat last week: eat 100 McChicken sandwiches from McDonald's in 24-hours.

And no vomiting.

“I’m a fan of the McChicken,” Metcalf said, “I’ve always loved them.”

He didn't think he could eat 100. Maybe a professional eater. Not a chemical engineering major. But he decided to give it his best shot.

Metcalf spent the weekend working out, burning calories in preparation for a massive all-day meal.

Not incidentally, 100 McChickens is 35,000 calories worth of poultry, bun and toppings.

On Sunday night, he stopped at the McDonalds on Grand River Avenue in East Lansing and picked up the first 10, throwing several in the oven on low heat.

He started eating at 4:30 a.m. The first four went down easy, Metcalf said. But a hurdle soon emerged in his one-day-only dollar-menu diet: mayonnaise.

“Too much mayo makes a man weak,” Metcalf said. “It was really hard to eat that amount of mayo.”

Metcalf is a man of principle. He could have ordered the next batch of sandwiches without mayo, but that would have violated the spirit of the challenge. He pressed on.

Each time he stopped at the McDonalds on Grand River, he’d order five more sandwiches. He pan-fried a few to get them crispy and tried chopping up one sandwich for a change of pace.

Four hours into the challenge, he stuffed his backpack with McChickens and made his way to his 9 a.m. process controls class. He remembers getting puzzled looks when he pulled out McChickens along with his notes.

Metcalf broadcast his efforts via Snapchat during the course of the day. Some clips included tips for preparing McChickens after refrigeration. Others showed him ordering additional sandwiches at the drive-thru. In one video, Metcalf munches a McChicken in his car as Taylor Swift's "Back to December" plays in the background.

He knew he was gaining steam when his friends started texting him to say he was the entirety of the MSU Snapchat stories page.

The story had more than 5,000 views on Snapchat, said Andrew Seng, a friend of Metcalf's.

By the time Metcalf was nearing 20 McChickens - having exceeded Seng's prediction - he agreed to buy his friend the next five.

"Personally, I had him at 16 or 17," Seng said. "He definitely surpassed what I thought he could do."

But after the 24th, Metcalf admitted defeat. It was taking him 30 minutes to eat each sandwich at that point. He knew he didn't have enough time to finish, not without hurling.

A 25th McChicken went uneaten. He hasn’t had a McChicken since.

“The day after I was grossed out, but today I could order one,” Metcalf said.

He’d skip the mayo.

Contact RJ Wolcott at (517) 377-1026 or rwolcott@lsj.com. Follow him on Twitter @wolcottr.