Army veteran, John Burk, 31, says that he is not going to accept overweight people for who they are, "with that bullshit excuse of ‘you should love me because I’m beautiful’".
"Your personality might be beautiful, but your body is not," he says. “It is not okay to be overweight."
The video has since racked up nearly three million views and has received a mixed response from viewers.
Burk says that he doesn't take issue with people who have thyroid problems, but he does have a problem with "lazy" people who become obese. As a result, he says, parents allow their children to be obese, "because they can't teach them right, because they're too lazy to cook a healthy meal".
This causes the young children to get bullied, he says: "Bullying is out there and who do they go for first? The overweight kids.
"I don't agree with it, I was bullied, but that's just the way it is," he adds.
He then goes on to discuss how to implement a healthier way of living in baby steps.
"If you want to start out, cut your sugary drinks," he says. "Cut all your sugar, slowly but surely implement one healthy meal a day. The next week or two weeks later: two healthy meals or three healthy meals a day.
"Go walk for ten minutes, jog for ten minutes, get a gym membership, do something," he adds. "Get your kids off the fucking couch first and foremost."
His expletive-filled rant has been met with both praise and criticism.
Markola Yanga commented on the video: "I'm overweight and I totally agree with this, but I'm already making changes. Good tip!"
Another user, Marieli Garcia added: "John I respect you so much brother for saying what a lot of people are afraid to say.
"I'm overweight and I've been like this since I was child. I don't take offence to this video because it's true I've been lazy and not wanting to workout out. My biggest problem is soda. I'm 5'4" and weight 200lbs, it's crazy I know but this year I decided to do something about it.
"I finished my first Spartan sprint in NY and that inspired me to do better for myself. I would like to thank you though for giving me the blunt truth and not a bullshit excuse. Stay safe."
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The Worst Fitness Advice
While the majority of people commenting on the video were positive about what Burk had to say, others have hit back about it.
"What business is it of yours whether people are fat or thin? What right have you got to criticise fat people?" said one Facebook user.
While another added: "This guy is an idiot. I watched up to the fat kids get bullied bit and couldn't hear anymore bullshit.
"I'm a personal trainer and client's lifestyles can't always be as active as they want due to work/life commitments and sometimes they need a bit of motivation and knowledge. Being overweight is a ridiculous statement and doesn't mean you're unfit or unattractive.
"Who would want this guy shouting this bullshit at them in the gym? Very unapproachable."
The video concludes with Burk pointing out the harsh reality of obesity.
"This isn’t me being fucking angry. This isn’t me trying to fat-shame," he says.
"This is me saying you need to change your life before a doctor comes in and says, ‘Look, I’m sorry, there’s nothing else I can do, we have to take the leg’.”