Until the age of 10, twins Reagan and Grace Freeman were like two peas in a pod living in a suburb of Houston, Texas.
After they moved to another state, their mother, Cindy Freeman, noticed that Reagan started rejecting foods she used to love, exercised nonstop and complained daily of a stomachache.
Believing her daughter was reacting negatively to the move, Freeman tried to take her to a psychiatrist but ran into a roadblock. "I called every psychiatrist in the city and no one would see her until she was 11," she told ABC News.
Determined to get her daughter treated, Freeman then brought her to a medical doctor.
"He said, 'Well, she's a little on the thin side. She just needs to eat more,'" Freeman recalled.
She said he didn't recognize how serious Reagan's situation was, despite her losing 30 pounds in a six-month period.
Freeman finally began calling eating-disorder clinics across the country in an effort to get a psychiatric recommendation. One by one, each of the clinics told her Reagan needed more than a psychiatrist; she needed to get admitted to inpatient treatment immediately.
Reagan was diagnosed with anorexia nervosa, a classified mental illness. She was just 10.
Experts say the national focus on obesity has meant that doctors and parents aren't trained to look for or treat eating disorders in the very young. An estimated 33,000 U.S. children between the ages of 8 and 15 are diagnosed with eating disorders, according to the Centers for Disease Control and Prevention and the National Institutes for Mental Health. Children as young as 5 have been diagnosed with the illness.
Doctors say the distinction between healthy activity and overexercising can be hard to recognize in children. It can also be difficult for doctors and parents to distinguish between a child's predilection for picky eating and a drastic change in eating patterns, they said.
In Reagan's case, she often jogged in circles inside her room and ran four miles a day while walking the dog. She then started throwing away her lunch at school or hiding food in toilet paper dowels.
"We would spend two hours just trying to get food down her stomach," Freeman said.
Reagan once sat at the table for more than four hours until she ate dinner. "It's hard for someone to eat food and there's this voice inside their head telling them not to," Reagan said.
Verbally expressing concerns about weight gain is crucial in diagnosing adults and adolescents but young children often don't have words for what is at the root of the illness: fear of weight gain and distorted body image.
After spending three months at an inpatient facility 1,000 miles away in Colorado, Reagan returned home before Thanksgiving. The whole family is involved in her ongoing recovery.
"It's hard on her sister. … Everyone has to watch her during every snack and every mealtime. She's gotten very good at hiding and sneaking and throwing things away," Freeman said.
Working with a nutritionist and therapists, the Freemans attend family-based therapy, also known as the Maudsley Approach. It has a 50 percent to 60 percent full recovery rate within a year, according to a 2013 Journal of Adolescent Health study.
It encourages parents to take the reins, counterintuitive to a doctor's inclination to take over. But parents and experts told ABC News that the method has shown the most effective results.
"It's getting easier," Reagan said of her recovery process. She said she still thinks about her eating disorder "a lot."
Reagan and her family came forward with their struggle because they hope it will help other families who have children struggling with anorexia.
F.E.A.S.T., or Families Empowered and Supporting Treating of Eating Disorders, is a nonprofit organization helping families overcome eating disorders.
The group provides a 24-7 online forum for families and sufferers of the disease, a localized list of eating disorder support groups, a recipe book geared toward those recovering from eating disorders and countless other resources to educate people on eating disorders and the recovery process.
Freeman advised parents to "open your eyes and look."
"Don't listen to necessarily what a doctor or a psychiatrist or anyone else tells you, because you know your kid better than anyone," she said. "And don't think, 'No, this can't be an eating disorder, they're too young.' Go get help."
To learn more about F.E.A.S.T., visit here.
ABC News' Margaret Dawson contributed to this story.