Judith Shaw, a 50-something training to be a yoga instructor, was praised by friends and relatives for her amazing sinewy figure. But when she fell and broke her pubic bone, she had to reveal a dark secret, she told ABCNews: She had an eating disorder.

Studies have shown the majority of those affected by an eating disorder are young women, but the number of midlife women facing the same struggle is on the rise.

As Huff/Post50 recently reported, treatment centers have seen an increase in the number of middle-aged women seeking help for eating disorders such as anorexia and bulimia. The signs of an eating disorder -- such as lack of menstruation or loss of bone density -- are more difficult to spot in older women than in younger women, often leaving midlife women misdiagnosed.

At any age, damage to the body resulting from an eating disorder can be grave. Sarah Parker, director of anxiety and eating disorders at the Reeds Treatment Center in New York told ABC News:

"There can be significant damage to the heart and heart muscles," said Parker. "In really severe cases, the heart can stop functioning. Fat stores in the brain can become depleted and affect cognitive and neurological functioning. It can also result in osteoporosis and organ failure."

More than 10 million Americans suffer from some form of an eating disorder, including anorexia, bulimia and binge eating, the National Eating Disorders Association reports. An increase of 42 percent of middle-aged women with eating disorders was seen from 2001 to 2010.

Triggers of a midlife eating disorder can include the pressures of aging, relationships and personal loss. Shaw for example, told ABCNews that her husband had asked for a divorce after 35 years of marriage. "My body was crumbling as my life was crumbling," she said.

“Women at mid-life now have unprecedented opportunities and also unprecedented stresses,” Merryl Bear, director of Canada's National Eating Disorder Information Centre, told the Toronto Star. “There’s an increased fear of aging and societal pressures to change one’s body to bring it closer to the societal ideal.”

The popularity of svelte post 50 icons such as Julianne Moore, Sheryl Crow, Susan Saradon and Jane Fonda inspire admiration but also a certain pressure to be "fabulous over 50." (Although this isn't necessarily a new phenomenon: In his 1987 novel Bonfire of the Vanities author Tom Wolfe described the emaciated wealthy wives of investment bankers as "X-rays.")

As psychiatrist Anne E. Becker -- director of the Eating Disorders Clinical and Research Program at Massachusetts General Hospital and president of the Academy for Eating Disorders -- recently told Harvard Women's Health Watch:

As our society values youth and as baby-boomers reinvent what it means to be middle-aged, there are growing social forces that can undermine older women's self-esteem and potentially lead to body dissatisfaction — for example, if you think the surface of your skin or the contours of your body aren't supposed to match your chronological age. That, combined with health concerns about obesity, can make people feel bad about their bodies and, in turn, could result in eating strategies that undermine well-being.

In addition, experts have found that eating disorders in midlife are often carried over from adolescence, but new cases are possible.

"It’s rare -- not impossible, but rare -- for a woman 50 or beyond to develop an eating disorder for the first time," Dr. Margo Maine, clinical psychologist and co-author of The Body Myth: Adult Women and the Pressure to Be Perfect told the Huffington Post. "Most in their 50s and 60s are women who had eating disorders when they were younger."

Shaw, for her part, told ABCNews she regained her "sense of worth and purpose" through sculpting, which gave her a better perspective on her anorexia. Her "Body of Work" exhibit has now toured several top medical schools and been used as an instructional tool to help students better understand patients with eating disorders.

If you're struggling with an eating disorder, call the National Eating Disorders helpline at 1-800-931-2237.