6 Reasons Behind Unintended Weight Loss, According to a Doctor

Many people would jump up and down in excitement if they saw the scale taking a drop. But weight loss isn't always a good thing, especially if you're not taking the steps to actually make it happen. Health conditions and related factors can cause weight loss at a rapid pace. Everyone's body is different, but losing five percent of your body weight after six months is generally a cause for concern in medical reviews. However, if you notice that you're losing weight much quicker than indicated in your weight-loss plan, talk with a clinician.

Keep in mind that there are many reasons someone could be losing pounds, but these are just a couple of the more familiar ones. Brian Secemsky, MD, an internal medicine physician at OneMedical, filled us in on some of the reasons you could be experiencing unintended weight loss.

Stress and Mental Health Conditions

"Some people are stress eaters, but some people are the exact opposite," Secemsky said. "They will eat less and avoid foods that give them pleasure because they feel they need to hold off on it until they're happy." People who get stressed — from work, family, etc. — may drink a lot of caffeine, which is an appetite reducer.

However, it can go beyond stress. People with depression, anxiety, and mental health conditions may experience loss of appetite. Many of these people lose interest in things they love, and that can include food.

Thyroid Issues

An underactive thyroid is linked with making it extremely difficult to lose weight. On the other hand, an overactive thyroid (hyperthyroidism) can cause just the opposite reaction. Each condition also causes other issues, so you'll want to talk to your doctor about any major weight problems.

One of the best things you can do is keep a symptom journal, Secemsky said. If you notice unintended weight loss, keep track of other changes, even if you don't think they're related. Telling your doctor about your fever, hair loss, changes in urination, and even a cough can have bigger implications than you realize. For example, sensations of cold or heat could be linked to thyroid issues.

Celiac Disease

People with celiac disease can't eat gluten, a protein found in wheat, rye, and barley (basically your favorite carbs). When they do eat gluten, the body sends a response that attacks the small intestine. "You can't digest certain foods and you also have this chronic inflammation going on," Secemsky said. This can defer eating and cause other stomach issues, leading to weight loss. Consider gluten-free desserts your new best friends!


"Medications, recreational and prescribed, can also cause unintended weight loss for various reasons," Secemsky explained. Some cause nausea or dry mouth, and others directly cause unintended weight loss. So look at what medications you're taking, as well as your medication history, if you've noticed a drastic weight change.

Type 1 Diabetes

Type 1 diabetes (specifically when it's undiagnosed) can cause rapid weight loss. The glucose in the bloodstream doesn't get into the cells of someone with the condition. Therefore, their body isn't getting those nutrients. That extra glucose can also cause a patient to urinate more and become dehydrated, Secemsky explained. All of this can cause a lower number on the scale.

Substance Abuse

"Particularly, if patients are using stimulant medications like cocaine, unprescribed use of ADHD medications, and even caffeine, they can be appetite inhibitors," Secemsky said. For some recreational drug use, the addiction is so strong that people forgo eating, whether it be financial reasoning or they just use the time to do more drugs. Researchers from the University of Cambridge even found that cocaine may reduce the body's ability to store fat.

Many of us could say that we would love to lose a couple of pounds; however, only you truly know your body's "normal." So if it seems off, always reach out to your doctor. And, yes, that includes when you think you're losing weight a little too quickly!