A Tennessee grandfather told Fox News on Friday he is on a 100-day, McDonald's-only diet he predicts will help him lose weight and improve his cardiovascular health — and it's already working.

Kevin Maginnis of Nashville is documenting his journey on his TikTok account at @bigmaccoaching, with his first video posted Feb. 21. He reported being down 13 pounds — from 238 to 225 pounds — 11 days into his diet. 

Maginnis told "Tucker Carlson Tonight" Friday that unlike most approaches to fast-food meals, he is adhering to moderation and portion-sizing.

"I was a boxer, I wrestled in school, and you have to cut to make weight, so cutting the calories, cutting the food in half. If I eat three meals a day, if I cut them in half and I seek the heat before I eat, meaning I wait until that heat in your stomach that says you're hungry," he said.

"Everyone else calls it hunger. I call it my incinerator turning on to get rid of all the excess and also burn off some of the fat off my body, and then I'll have that next meal."

Maginnis' diet brings forth memories of the 2004 documentary film "Super Size Me," during which filmmaker Morgan Spurlock ate only McDonald's for 30 days and cataloged the effects, such as large volumes of calories, had on his body and psychological well-being.

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About a month after the film's release, the McDonald's Corporation discontinued its famous "Super Size" meal option.

A McDonald's restaurant sign is seen at a McDonald's restaurant in Del Mar, California April 16, 2013. REUTERS/Mike Blake

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During his McDonald's diet, Spurlock gained about 24 pounds, and reportedly experienced mood swings.

Maginnis predicted his diet will have the opposite effect, telling Carlson the key to his plan is cutting each meal in half. 

He said his diet does not have a meal-time regiment or meal measurements — he just cuts each meal in half and saves the remainder for the next meal.

He predicted a 50-pound weight loss by the end of his 100 days, along with better bloodwork and overall health.

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Bradford PA oil pumpjack

An oil pumpjack operates in the drive-thru area of a McDonald's in Bradford, Pennsylvania, U.S. October 6, 2017. REUTERS/Brendan McDermid (Reuters)

When asked how a leftover half of a McDonald's value meal tastes, Maginnis said he takes the remaining half of a burger and microwaves it alongside a mug of water to help steam the bun and contents so it does not dry out.

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For reheating fries, he said an air fryer or dry skillet can help retain crispness.

"After you've done it for about three or four days, your stomach will have shrunk a little bit, and then you can just eat the half, and you can wrap up the other half after you've eaten half of it," he said.

"As far as, ‘Is it going to kill me?’ I did the blood work at the beginning. We'll do bloodwork throughout. My belief is that it's going to absolutely improve the bloodwork throughout the whole process."