Fitness Trainer Eats McDonald’s for 2 Weeks, Loses Weight Debunking Myths


A personal trainer set out to prove the actual factor behind successful weight loss by eating McDonald’s every day for two weeks and dropping pounds in the process, to debunk popular myths about weight loss and dieting.

Fitness instructor proves you can eat anything and lose weight

Calling many popular dieting fads “more often than not, a load of nonsense,” a personal trainer set out to debunk accepted wisdom and identify the real factor that provides weight loss, LADBible reported.

To prove the point, Irish fitness instructor Oisin Mulligan went on a mission. He posted videos on his TikTok account, using himself as the guinea pig, in an experiment where he went on a diet of McDonald’s food for two weeks straight. He aimed to show that the food itself wasn’t the factor in achieving weight loss.

In a series of videos, Mulligan showed himself chowing down on a variety of foods from the Golden Arches.

“I’m doing this to remove fear surrounding food,” Mulligan proclaimed.

“No food will inherently make you gain weight – even if that food is a Big Mac from McDonald’s.”

Fitness instructor identifies key factors in weight loss

At the start of the experiment, Mulligan weighed himself. He tipped the scales at 180.99 pounds (82.1 kilograms).

Mulligan said his weight loss would come through calorie control.

“I’m doing it by staying in a calorie deficit,” Mulligan explained. “Essentially, our body burns so many calories per day or utilizes so much energy every day, and if you just eat a little bit less than that, no matter what you eat, within that you will lose weight.”

Despite only eating food from McDonald’s, eleven days later Mulligan had lost 3.74 pounds (1.7 kilograms).

Additionally, Mulligan made sure he took 10,000 steps daily and performed other exercises as well.

Calories are the deciding factor, trainer proclaims

In the experiment, Mulligan proved it’s not necessarily what you eat, but how much you eat, as well as the level of your daily activity.

“If this doesn’t show that calories are the deciding factor in weight loss, then nothing will,” Mulligan claimed.

“All diets work by creating a calorie deficit, but most do it by restricting full food groups, such as carbs,” Mulligan argued. “And I’ll say it again, restriction leads to failure!”

Mulligan’s point is that restricting yourself from certain food groups is not what matters – the key factor is limiting your caloric intake.

Stop vilifying food

Mulligan did not advocate eating only at McDonald’s, as during the experiment, he ate other foods as well to obtain needed daily vitamins and minerals. His point was to challenge the concept that certain foods are “bad.”

“People feel afraid of certain foods or feel like they can’t consume the foods they enjoy and lose weight at the same time,” Mulligan stated. “If someone calls your food bad or says McDonald’s is inherently bad or your chocolate bar is bad when you consume that food, it makes you feel bad.”