TikToker Eating Nothing But McDonald's For 100 Days Says He's Losing Weight. 'From French Fries to Fit Guy.' Kevin Maginnis says the fast-food fitness plan proves that it's not what you eat but how much you eat.

By Jonathan Small

Last month, Kevin Maginnis went on his TikTok channel @bigmaccoaching to try a weird weight-loss experiment.

"I'm going to eat nothing but McDonald's for the next 100 days, the 56-year-old Nashville native said, "but instead of eating everything they give me, I'm going to go ahead and cut the meals in half just to prove to myself and maybe some of the other people watching that it's not as much what you're eating, it's the quantity that we're eating that really jacks us up."

@bigmaccoaching Challenge: Eating mcdonalds every meal for the next 100 days to lose weight! #mcdonalds #mcdonaldschallenge #weightloss #bigmaccoaching #transformativecoaching #nashvilleweightlosstransformation #weightlossjourney #100daychallenge ♬ Inspiring Emotional Piano - Metrow Ar

That video now has 573,000 views.

Maginnis started his unconventional weight-loss plan weighing 238 pounds. He has chronicled every day of his diet on TikTok, eating three meals daily, but only half of the meal.

If you think all Maginnis is only eating salads and yogurt parfait, you'd be wrong. He's eating from the full menu, including Egg McMuffins, Fries, and Big Macs. The only rules are to eat half, only drink water (so soda or juice), and no snacks in between.

Some TikTok users expressed concern about food waste, but Maginnis assured them he was saving each un-eaten meal and eating it the next day.

Related: Some McDonald's Franchisees Aren't Happy With Cardi B and Offset's New Meal, Despite Proven Success of Celebrity-Tied Promos

Is the diet working?

Maginnis claims to have lost 12.5 pounds in 10 days. Yesterday, he went on the Today Show to discuss his journey, saying he estimated dropping 50 pounds in 100 days.

"My health will be better. My blood work will be better," he said. "And if you don't believe me, follow along. Let's find out."

Maginnis isn't the first to try this experiment. In 2014, a high school biology teacher John Cisna only ate only McDonald's for 90 days, asking his students to design his menu. By the end of 3 months, he'd lost 37 pounds.

But most nutritionists and doctors do not recommend Mcdonald's for three meals a day. Sure, you may lose weight, but other health issues must be considered, including the detrimental effects of diets high in sugar, sodium, and fat.

"One of the most immediate effects of eating at McDonald's is feeling extremely tired and groggy after your meal," said Bansari Acharya RDN, a registered dietitian nutritionist told Eat This, Not That. "Your body feels like it has low energy due to it trying to digest the overload of fat and sugar."

Fast Food has also been shown to raise cholesterol levels, destroy healthy gut bacteria, and make you more susceptible to diabetes.

Jonathan Small

Entrepreneur Staff

Founder, Strike Fire Productions

Jonathan Small is a bestselling author, journalist, producer, and podcast host. For 25 years, he has worked as a sought-after storyteller for top media companies such as The New York Times, Hearst, Entrepreneur, and Condé Nast. He has held executive roles at Glamour, Fitness, and Entrepreneur and regularly contributes to The New York Times, TV Guide, Cosmo, Details, Maxim, and Good Housekeeping. He is the former “Jake” advice columnist for Glamour magazine and the “Guy Guru” at Cosmo.

Want to be an Entrepreneur Leadership Network contributor? Apply now to join.

Buying / Investing in Business

Former Zillow Execs Target $1.3T Market

Co-ownership is creating big opportunities for entrepreneurs.

Science & Technology

7 AI Tools to Build a Profitable One-Person Business That Runs While You Sleep

Smart systems to help solo founders scale fast.

Business News

Most Major Retailers Are Open on Memorial Day, Except One. Here's What's Open and Closed This Monday.

From grocery stores to warehouse retailers, here's what to know about Memorial Day closures.

Business News

'I Run My House Like a Military Operation': Skims Chief Emma Grede Says This Is Her Precise Daily Routine

Grede is a CEO, founder, and serial entrepreneur. Here's how she prioritizes her day.

Business Ideas

70 Small Business Ideas to Start in 2025

We put together a list of the best, most profitable small business ideas for entrepreneurs to pursue in 2025.

Social Media

How To Start a Youtube Channel: Step-by-Step Guide

YouTube can be a valuable way to grow your audience. If you're ready to create content, read more about starting a business YouTube Channel.