With his washboard abs, chiseled pecs and nearly 200 pounds of muscle, David Laid looks to be the poster boy for physical perfection.
But just four years ago, Laid, then 14, weighed just 98 pounds. He said he was bullied in school for being scrawny.
"Every aspect of my life was heavily impaired by how insecure I was and how I looked. I was an absolute twig," Laid, 18, said.
Desperate for a change, he turned to YouTube videos for advice on how to transform his body.
"I kind of came home with it, and I went on YouTube and I typed in, 'chest workout,'" Laid recalled.
Now, Laid has become a social media celebrity. His transformation video that chronicles his weight-gaining odyssey has more than 14 million views on YouTube.
"I think it's the completely massive change in a human being. I was a small skinny kid and all of a sudden, it's a completely massive transformation," Laid said.
He lifts sometimes up to six hours a day and eats nearly 5,000 calories daily, posting it all on social media.
You could call what he does "bigspiration," following the trend of other young men like Laid, who post videos of themselves flexing and working out and gaining millions of views.
But for some, the desire to bulk up can just as easily be an obsession, leading some young men down a destructive path of compulsively dieting and working out, but never feeling quite big enough.
Dr. Jamie Feusner, an associate professor in the UCLA Department of Psychiatry and Biobehavioral Sciences, says the portrayal of the ideal male body size and musculature in movies, television and magazines seems to have become “more and more inflated” over the years.
"[It's] to the point where it'd be very difficult for anybody to kind of achieve this," Feusner said.
For 29-year-old web designer Dylan Hafertepen, the quest for maximum muscle has been a lifelong struggle.
"I used to look at [bodybuilders] and really beat myself up, because it's like this is so out of reach, and why am I not there?" Hafertepen said.
When he was 18, the California native weighed 140 pounds, but in the seven years that followed, Hafertepen doubled his size by following intense workouts, drinking six protein shakes a day and spending half of his paycheck on supplements.
His entire life was devoted to his body.
"I would always choose to work out over hanging out with friends. I would not go out to eat. I had my meals prepared and I would eat them all by myself. I usually picked jobs where offices were near a gym. I was so caught up in that lifestyle, so obsessed with the ever-moving goalpost of getting bigger, bigger, bigger that I never really considered this a problem," Hafertepen said.
Despite getting up to 265 pounds and sporting 20-inch-biceps, Hafertepen said he still never felt big enough.
"I perceived myself as very small and weak and inadequate," Hafertepen said. "I would get very upset about how small my arms seemed in proportion to my waist ... my shoulders to my neck ... I would focus on all these things that made me very upset."
Hafertepen says the muscular men in the videos he watched and the motivational photos on social media were a trigger.
"You don't see any average-looking superheroes. Everyone was this hyper-masculine or superior male, and I definitely see that now in a different light on Instagram, social media, Tumblr. You see these hyper-realized imageries of men in the same way and that can create this false idea of what the male physique should be," he said.
Ultimately, Hafertepen's infatuation with getting huge landed him in the hospital. He had gotten so big that his blood pressure became so high, he had to have his heart shocked back to normal.
"When I was younger -- before I was taking therapy seriously -- I had negotiated with myself that it would have been okay to succumb to death at an early age by pushing myself beyond what my body was capable of. There's no amount of size I could have added in that head space that would have fixed that," Hafertepen said.
After his brush with death, Hafertepen said he realized he needed help. It turned out his quest for the perfect muscular body was actually a psychological condition known as muscle dysmorphia, which is more commonly called bigorexia.
"People with muscle dysmorphia have a belief or perception that their body is too small or scrawny, that they're not muscular enough, and they have a very strong desire to become bigger," said Dr. Feusner.
Roughly one in 50 people in the United States have been diagnosed with body dysmorphic disorder, and it affects just as many men as women. Up to a quarter of those people are believed to be muscle dysmorphic, which is sometimes called the reverse of anorexia.
"Bigorexia happens more frequently in males, anorexia more in females. People with anorexia nervosa think that they're too fat, too large and want to become thinner, whereas people with bigorexia think they're too small and want to become bigger," said Feusner.
People who work out, including hardcore devotees like David Laid, don't necessarily have a problem. They see their ideal body as achievable naturally.
"I would like to increase my muscle mass, increase my strength and I'm doing that by going to the gym and training consistently," Laid said. "I'm by no means ridiculously obsessed with it where it's taking over my life. It's just something that I enjoy doing. That's just what I do."
After years of therapy, Hafertepen says he's stronger now inside and out.
"The biggest difference is that I have a greater appreciation for myself. I can now look in the mirror, and I am not hung up on these preconceptions of how I look. I'm not obsessed with focusing on flaws, how skinny I am, how weak I am. I see beautiful Dylan," Hafertepen said.