In bed asleep, eating, in her underwear or even displaying her scars after weight-loss surgery, photographer Jen Davis has always been as comfortable in front of the camera as she is behind it.

But when Davis, 36, set out on a "journey of self-discovery" to explore her own weight problem through a series of self-portraits, she discovered a side of herself she didn't know existed.

The results were just published in the book 11 Years. Davis came up with the idea in 2002, when she was a student.

"I was at the beach on a spring break vacation. I guess I hadn't been in a bathing suit for a while, and there was this heightened sense of being very uncomfortable," she says.

"That was the starting point - to look at my anxieties."

The resulting photograph, entitled Pressure Point, showed her sitting awkwardly on the beach next to a svelte and toned friend in a bikini.

Davis began photographing herself in everyday situations, initially choosing images that were "safe and easy", such as hanging her laundry or having a meal with a friend.

"I wasn't thinking about an audience, and I knew I didn't have to show them to anyone, so it didn't inhibit me from taking pictures that were hard to look at," she says.

But as the project went on, she started to challenge herself to reveal more flesh with pictures of her trying to do up the waistband of her trousers or showing a close-up of her chin.

"I realized that I was looking at this private side of myself that I didn't know, looking underneath this shield of how I projected myself to the world," she says.

Journey of self-discovery

Over the following years, Davis, a Brooklyn-based photographer who specializes in portraits, amassed hundreds of photographs of herself.

But nearly a decade after beginning her photographic project, she realized that despite the years of self-discovery, her weight remained unchanged.

In 2011, she decided to undergo weight-loss surgery by having a gastric band fitted.

As the pounds fell off - 52 kilograms within a year - Davis came to realize just how much the excess weight had dominated her life.

"It was all about my body and discomfort and dealing with pressures that I felt, like feeling scrutinized by people's eyes," she says.

"I felt judged in society. On the subway I felt that people were staring at me or making fun of me," she says.

"Even if it was not in a verbal way, it was in a look, people staring or rolling their eyes."

The most upsetting experiences came when people tried to temper comments about her weight with what they saw as kindness.

"People would say: 'Oh you have such a pretty face, but your body needs to change'. Or: 'You're so overweight, but you're pretty. So if you lose weight, you'll be happy or have a boyfriend'," she says.

"That happened at a wedding. A woman said that to me, and I burst into tears."

'People were staring'

As the number of obese people increases worldwide - creating looming public health crises in some countries - Davis says the issue had become a minefield.

The most vicious prejudice is now expressed under the cover of anonymity on online forums and in comment boxes, she adds.

People in the public eye, meanwhile - such as the governor of New Jersey, Chris Christie, who opted for gastric bypass surgery without publicly announcing their decision - risked incurring the wrath of the public.

"All of a sudden, he was losing weight and the public was so angry that he didn't come forward with this," she says.

Having concluded that her own problem was caused by a psychological need to comfort eat, Davis knows she will have to work hard for rest of her life to maintain her new weight.

But she is grateful for the surgery without which she believes she could never have achieved it.

"Some people are 'fat positive'. But I could never see myself as beautiful or subscribe to that," she says.