So how skinny is too skinny? It’s hard to explain—and even trickier to calculate. A normal weight, according to the U.S. Department of Health and Human Services, is when your body mass index (BMI) falls somewhere between 18.5 and 24.9, but no two bodies are exactly alike and index numbers alone are not a good way to gauge your health.
Sadly, those nearing a painfully thin frame become less and less likely to acknowledge the problem. “Often patients say ‘I’m not that thin,’ that’s distortion, it’s not reality," says Fishman. And the same distortion can keep your scale dipping deeper in the wrong direction.
Whether you believe you’re underweight or not (no offense to the naturally thin), these are signs you may not be getting enough nutrients in your body.
Believe it or not, when your body is undernourished, you may feel energized and have an urge to move. “That’s the brain telling the body to start moving to go get food,” says Dr. Ovidio Bermudez, MD, Medical Director of Child and Adolescent Services at the Eating Recovery Center in Denver. And as your body begins to become anxious physically, you start to drag emotionally. “You become depressed, anxious, and fearful,” says Bermudez.
Your joints look large
If you’ve lost too much weight, you could be purging your body’s “good” weight—your muscle. “Most people think that as we lose weight we lose fat mass, but the reality is that we tend to lose more lean body mass than fat mass,” says Bermudez. The result is joints and bones that look over-exaggerated because of the loss of muscle tissue around them. Your skin can also become dry and wrinkled because it is losing its protection against your bones. “People begin to take sort of a hollow look,” he says.
Mother nature stops visiting
You may not jump for joy when your cycle kicks in, but an unexpected cancellation from Aunt Flow can be a sign that something is wrong. “Your brain is trying to figure out how to make it,” says Bermudez. A missed period is sometimes an alarm that your body is shutting down reproduction until it bounces back and gets enough nourishment to fully function.
More: 7 Simple Ways to Eat Less & Feel More Satisfied
Exercise is no longer fun
If going to your favorite spin class starts feeling like a chore, it may be a sign that you’re overdoing it. Obsessing over workouts to the point where they begin interfering with the rest of your life and feeling abnormally fatigued are also indications that it may be time to take a step back.
You’re up all night
Experiencing a mild case of insomnia? Before you blame that late-afternoon cup of joe, take stock of your eating and exercise routine. It’s much harder to sleep on a completely empty belly, and if you’ve been trimming too much from your diet, the same anxious/obsessive attitude that keeps you in the gym could be keeping you up all night.
There is no one-size-fits-all approach to reaching a healthy weight. If you are experiencing one or more of these changes, consider making an appointment with your doctor.