Does a Downward Facing Dog feel different when you have a double chin? Is Warrior pose more challenging when you're wider? Trina Hall, a Dallas-based Yoga teacher, aimed to find out.

After a discussion with an overweight friend who lamented being "the fat yoga teacher," Hall decided she wanted to experience for herself what it was like to stand before a class weighed down by folds of excess flesh. As a naturally svelte yogi, she had always thought of herself as judgment-free when it comes to body shape and size. But that conversation, especially the use of the word fat as the ultimate insult, affected her deeply.

Yogi Trina Hall before her intentional 40-pound weight gain. (Image Credit: Margie Woods Brown Photography)

"I saw her as fit and beautiful and nothing negative. I couldn't understand why she would assault herself in that way," Hall, 34, said.

Hall immediately started on what she called a SEAT diet, as in "see it, eat it." She packed 40 pounds onto her 5-foot-5 frame in just four months. At her peak weight, she tipped the scales at more than 170 pounds.

Yogi Trina Hall after her intentional 40-pound weight gain. (Image Credit: Napier Photographie)

What happened during Hall's experimental foray into fatness surprised her. As her weight climbed, her self-esteem plummeted. Instead of proudly displaying her body in a spandex yoga suit like she'd always done, she began hiding her body under dresses and wraps. She always thought she'd feel confident in her own body no matter what it looked like, but her self-talk quickly turned dark and critical.

"I feared no man would want me this way and that I would die alone, probably from choking on a potato chip," she wrote on her blog.

She kept the experiment a secret and waited for feedback. There wasn't any. She ate guiltily and worried her weight gain was like committing career suicide. Yet no one ever overtly criticized her and her yoga students never breathed a word to her about her ballooning girth.

Still, she noticed that people stopped making eye contact with her. And she couldn't say for sure, but she sensed people might be treating her differently.

"It was like the more visible I became, the more invisible I felt," she recalled.

Rebecca Puhl, the deputy director at the Rudd Center for Food Policy & Obesity at Yale University in New Haven, Conn., said she was not surprised to hear about Hall's experience.

"While many stigmas are concealable, fat is something you literally wear on your sleeve," Puhl noted.

Puhl said the fact that Hall picked up on all these perceptions so readily is evidence of how pervasive the stereotyping of fat people is in this society. Puhl's various studies show that about 15 percent of women and 8 percent of men report feeling discriminated against because of their weight. Those numbers have risen 66 percent since 1996.

Puhl's research has also found that prejudice against a superfluous waistline translates into numerous inequities across broad areas of life. For example, one of her studies revealed that 50 percent of doctors found their fat patients "awkward, ugly, weak-willed and unlikely to comply with treatment," while 24 percent of nurses said they were repulsed by their obese patients. Nearly 30 percent of teachers said that becoming obese was "the worst thing that can happen to someone."

Is Stigma Against Fat People The Last Acceptable Prejudice?

More than 70 percent of obese people in Puhl's studies said they had been ridiculed about their weight by a family member. And she found that people classified as obese generally wind up less well off socially, romantically and financially compared to their slimmer peers.

Hall's experiment ended in July. She put the brakes on her gluttonous eating habits and has shrunk back down to her typical weight of about 130 pounds. Though she said she worked hard to both gain and lose the weight, her body seemed to cooperate readily in both directions.

One of the biggest take homes from her experience, Hall admitted, is a greater empathy for those whose bodies don't cooperate so easily, especially the students who soldier through their yoga practice despite the extra pounds. What she thought would be an experiment in teaching her friend, herself and others to love their bodies no matter what, wound up being a lesson in how hard it is to be trapped in a body that doesn't fit into society's preferred mold of thin perfection.

Hall said she also understands her experiment might be interpreted as an attack on people who aren't able to lose weight or maintain a certain figure. She knows her story will probably make some people angry, but that was absolutely not her intent.

"I now have a firmer appreciation for students who work with extra pounds when they practice yoga and I see now it's a completely different sensation," she said. "I am a better teacher and a better human being as a result of this experiment."

So what do you think about Hall's story? Was it a noble attempt at empathy or the fat suit equivalent of black face? Share your thoughts in the comments section below.