PHILADELPHIA (WPVI) -- Eating disorders are serious medical conditions that can devastate someone's overall health and they tend to first surface during the teen years, young adulthood but can also appear in adolescents.
Alyssa Wendel first became aware of her negative thoughts in high school.
"One of the things I was most scared about in going to college was gaining weight. Because, you know, they always talk about the freshman 15," she said.
And when she was at college: "I didn't go to the dining hall. There was this spot where you could just get food to go and bring it back to your room," said Alyssa.
Dr. Russell Scheffer, a Cigna Medical Principal in Behavioral Health, says an obsession with weight, being very restrictive about food, and having excuses for not eating are common red flags for eating disorders. So is secrecy about eating habits.
"Young folks are very good at hiding it," he said.
Spending time in the bathroom after meals is another warning sign, as is always wearing long sleeves - even in hot weather.
However, Alyssa says that's not just for secrecy.
"You're always cold. It's just your body's way of protecting itself," she said.
The teen years are prime time for eating disorders.
"They've got a lot of things going on with their bodies that they just don't understand," said Dr. Scheffer.
"Usually something in the environment, a stressor, a loss, something will trigger it," added Samantha DeCaro, Psy.D. from the Renfrew Center.
DeCaro says pressure to be like the perfect images shown on social media can be a factor.
Some doctors say their cases nearly doubled in the pandemic due to the upheaval and isolation. Dr. Scheffer says medication is often needed to repair the brain chemistry.
"No matter what they look like or what they see in the mirror that they are, they're overweight and nobody can convince them otherwise," he said.
When Alyssa's physical health deteriorated, her family sought help at the Renfrew Center. Now, she sees food in a new way.
"Food is fuel. I need, you need food to live," she said.