It was Cassady Kinter's little secret.
"I was 14 so I was going into high school which I think is a really common time for people to start messing with that stuff," she said.
Cassady has Type 1 Diabetes. What she "messed with" was her insulin, skipping doses. It's not so rare, according to Seattle Children's Doctor Yolanda Evans.
"Diabulimia is a term for kids who have diabetes who use insulin, but they'll withhold their insulin in order to lose weight," Dr. Evans said.
Trouble is it works better than any diet. That's why got Cassady hooked.
"You can lose like 10 pounds in two days which is really appealing to a young kid who doesn't really care about consequences later on."
Those consequences would come much sooner than Cassady ever expected. At age 16, she developed cataracts. That's not the only danger of diabulimia.
Dr. Evans says it can be life-threatening. "A diabetic who doesn't take their insulin can have really elevated levels of sugar in their blood and can actually lead to coma, even death."
None of that registered with Cassady. She only cared about being thin.
"You lose weight very quickly and people notice and give you all kinds of compliments, of course," she said.
Then came the extreme fatigue, hair loss and other side effects. Yes, the pounds were coming off, but not in the way she expected.
If somebody has diabulimia a lot of times the body shape will be kind of this potato with toothpicks, spindly arms and legs," Cassady said.
The compliments stopped. So did the friendships. Cassady was the only one left playing the game of pretend.
"I thought I was fooling people but I wasn't."
Finally she got tired of feeling awful, but even then, it wasn't easy to stop. She got treatment but later relapsed before finally getting back on track again.
Cassady says the best thing parents can to do is look for the signs; be direct but not judgmental. Red flags include: unexplained weight loss, extreme fatigue, frequent urination and high blood sugar readings.
These days, Cassady is back in school, taking graduate courses to become a counselor to help others who go down the same dangerous path that she did.
Diabulimia has been seen in patients as young as 13 and in women as old as 60.