Katherine Ormerod remembers when she first signed up for Instagram.
Even more than that, she remembers how it made her feel.
"I was asked by my boss to set up a social media account -- it became part of my professional life -- but soon I realized it was having detrimental impact on my body," Ormerod told ABC News. "I never had big problems with anorexia, but I just never felt good about my body because of social media."
Ormerod, an influencer who authored "Why Social Media is Ruining Your Life," said that she realized during a trip with friends what was she was seeing -- and what she was posting -- didn't tell the whole story, and "something inside me just snapped."
"We spent so much time talking through personal and professional struggles," she said, describing her trip, "but then I scrolled through the pictures and it was only margaritas, sunsets and this easy-looking life."
Similarly, other influencers and bloggers and public figures who post to social media raving about the latest diet trends or clean eating aren't always sharing the whole picture -- and in doing so, may be creating potentially harmful scenarios.
Some people are at risk of developing an unhealthy obsession with exercise or clean eating, according to some experts, who've dubbed such a condition Orthorexia Nervosa.
"Orthorexia is not an official Diagnostic and Statistical Manual diagnosis, however we are hearing about this more and more recently from clinicians," Claire Mysko, chief executive officer of the National Eating Disorders Association, told ABC News in an interview.
Orthorexia Nervosa was coined in 1997 by Dr. Steven Bratman, a physician practicing alternative medicine. Bratman noticed that while healthy diets had been adopted by some in lieu of medications, certain individuals became obsessed to an unhealthy degree.
Young adults, particularly women, are most at risk for eating disorders, "but it could really be anyone," said Shelley Kendra, R.D., L.D.N., the clinical nutrition manager at UPMC Magee-Women's Hospital. "There are also men out there with eating disorders -- so I don't think it singles out anyone -- but young adult women may be more predisposed."
Among environmental triggers that fuel restrictive eating, social media may be the most influential.
"We are being bombarded with messages about what is healthy," Mysko. "It is a more confusing landscape for people to navigate as more and more products and trends are being placed in the category of health and wellness by companies."
Orthorexia can create a significant amount of distress. Somewhat ironically, being overly dedicated to healthy eating can jeopardize one's health.
Even without an official diagnosis, orthorexia can cause permanent damage reminiscent of anorexia nervosa or bulimia -- increased risks of malnutrition and heart disease, negatively affected cognition and fertility, and a weaker immune system.
Orthorexia also may be tougher to spot in an individual because healthy eating is so frequently applauded.
An estimated 8.4% of women and 2.2% of men grapple with an eating disorder at some point of their lives. The earlier an intervention can happen, the better the chance for a speedy recovery.
"Ask yourself whether your attitude around food and body image is unhealthy -- whether it is difficult to engage with others and feel good about yourself," Mysko said.
Although it's important to be aware of how much time and energy are spent on food selection, "each patient's treatment is extremely individualized," said Kendra, adding that it's vital to "figure out the triggers and what their thoughts are to help overcome their barriers."
And it's important to understand how those triggers and barriers are influenced by, well, influencers.
"What people are seeing is not a reflection of a lived life -- it's a highly edited best 1%," Ormerod said. "When I'm shooting for my girlfriends, we can take 300 or 400 pictures, and of that we will choose one. If you put your very best next to your very worst, they can look unrecognizable from each other."
Parents have a key role to play in how online content seen by their children potentially affects their eating habits and how they view themselves.
"The problem," Ormerod continued, "is we are very harsh on ourselves, and when we look in the mirror we hone in on what is the 'worst' and compare that to what people post as their very best.
"You are what you eat. It's called a feed for a reason, and I think the way we feed our brain and the content we put in has a massive impact on our mental health. Look at 'diet' as part of what you're doing with social media."
If you or someone you know is in crisis, please call the toll-free National Alliance on Mental Illness helpline at 800-950-NAMI. For more information on eating disorders, including warning signs and how to find support and help, visit the National Eating Disorders Association website.
Eden David, who studies neuroscience at Columbia University and is matriculating to medical school later this year, and Yalda Safai, M.D., M.P.H., a psychiatry resident in New York City, are contributors to the ABC News Medical Unit.