Reynolds said the pleasure in gaining weight could also demonstrate a need for "power and control and competence and seeing the self as a larger and more powerful person."
Many other cultures value the larger physique, he said.
But Keith Ayoob, director of the nutrition clinic at Albert Einstein College of Medicine in New York City, worries about gainers like Git.
"This guy is trying to gain a lot of weight by eating, unfortunately, a really bad diet," he said. "This is not the guy who is going to dive into a salad."
By gaining only fat rather than muscle tissue, or a "big belly," gainers put their health at risk.
"I know it's different strokes for different folks, but my second concern is he really doesn't want to change," said Ayoob.
Obesity eventually impedes blood flow and makes sex physically more difficult, according to Ayoob.
"The fetish may be in our heads, but the plaque is going to be in his arteries," he said. "He might think this is cool, but his body is keeping score."