I have yet to meet a patient who wanted to develop an eating disorder. Yet nearly all of them started the same way, trying to “get healthy.”

It’s the start of a new year, and a time for resolutions. “Getting healthy” is often at the top of people’s resolution lists.

As a double-board certified pediatrician and adolescent medicine specialist with expertise in eating disorders, one of the most common origin stories I hear goes like this: A teen was simply trying to make well-intentioned changes. Perhaps they heard from their doctor to “lose weight,” or a family member encouraged them to join a gym, or they learned in health class to “cut out sugar,” or they saw a supplement on TikTok that they started taking.

But then what follows is far from healthy.

Let me tell you what I see when these same teens return to my office just months later. When patients present 1, 2, or 3 months after these initial changes, the signs are unmistakable and alarming: they’re constantly cold, their heart rates have dropped to dangerously low levels, their hair is falling out, they’re no longer having regular bowel movements, they’re fainting, experiencing missed periods, and even suffering broken bones. They have an eating disorder.

So how does it go from “healthy changes” to an eating disorder so quickly?

To understand how this happens, we need to understand three critical factors about adolescent health:

1. Rapid weight loss in teens carries unique risks

Weight suppression (the difference between a person’s highest weight and current weight) matters more than you might think. Elevated weight suppression can predict the future emergence of eating disorders among adolescents.¹ Furthermore, greater weight suppression among young people aged 12–24 years who have eating disorders predicts more severe medical and psychiatric complications.²

2. Teenagers have exceptionally high nutritional needs

Energy demands are high during adolescence and require adequate nutrition to support function and wellness in adulthood. Neurocognitive, pubertal, and skeletal development during childhood and adolescence require adequate nutrition and metabolic activity. ³ Restricting intake during this time of tremendous nutritional need can quickly lead to medical complications and compromised development.

3. Adolescence is the highest-risk period for eating disorders to develop

Adolescents and young adults are at the highest risk for developing eating disorders, with the median age of onset at just 12.5 years of age.⁴

Given the slippery slope from cutting out foods labeled “unhealthy” to an eating disorder, we need to clarify what health really means.

So, what is health?

“Healthy” behaviors should be sustainable. They are more than the absence of disease. They should support the function of your body and mind, and provide you with the ability to adapt to life’s demands.

True health means having energy for the activities you love, eating foods that nourish and satisfy you, moving in ways that feel good, getting enough sleep and rest, managing stress and emotions, and having supportive relationships.

Health is your daughter having the energy to play soccer with her friends and not being too exhausted to focus in class. It’s your son enjoying pizza without guilt or anxiety.

If a version of “health” takes those things away, it isn’t health at all.