• Posted November 9, 2024

Unexplained Weight Loss and What It Can Mean for Your Health

It may seem counter-intuitive, but losing weight without even trying may not be a good thing.

"It's not typical to have a noticeable drop in weight without changing how much you're eating, being more physically active or trying to lose weight," said dietitian Christine Goukasian.

"Unexplained weight loss is a red flag," she added in a news release. 

Day to day, weight varies a pound or two because of hormones, water retention and other factors. Anything more may signal an underlying health problem — from cancer and gastrointestinal to mental health disorders. 

"Weight loss becomes a concern when it's 10 pounds or at least 5% of your original weight during a six- to 12-month period," said Goukasian, senior dietitian at the UCLA Division of Clinical Nutrition.

And older adults, especially those in community living, have a higher risk. As many as 2 in 10 lose weight unexpectedly — a share that jumps to 6 in 10 in community housing, where folks are more likely to have health issues that lead to unintended weight loss. 

More than a third of people who consult their doctor about dropping weight without trying have undiagnosed cancer. 

It is, according to UCLA, the No. 1 cause of unintentional weight loss, and about 4 in 10 cancer diagnoses begin this way. And dropping weight isn't just a sign of advanced cancer. Weight loss has been reported in patients with early-stage cancers of the colon, pancreas and lung, so it's important to see a doctor anytime weight begins to drop off unexpectedly.

Between 10% and 20% of unexpected weight loss owes to gastrointestinal (GI) issues such as chronic diarrhea, inflammatory bowel diseases, celiac disease or overuse of laxatives (often owing to an eating disorder).

Besides eating disorders, mental health issues such as anxiety, depression, obsessive-compulsive disorder and stress may also affect appetite.

"If you don't have much interest in eating or sleeping so much you are missing meals, you are going to lose weight," Goukasian said, adding that some medications used to treat mental health disorders may affect appetite, taste and smell and cause nausea.

These aren't the only culprits, however, she said. Others include dementia; thyroid disorders; diabetes; gum disease; as well as swallowing problems or any condition that makes eating uncomfortable. Financial problems or trouble getting enough food may also contribute.

"Not all weight loss is because of a life-threatening disease," Goukasian said. "Many times the underlying cause is treatable or manageable."

That's why people who have lost a concerning amount of weight should tell their primary care physician. He or she may do a physical and mental health exam, blood and urine tests and imaging to rule out potential causes.

"Identifying an underlying cause of unexplained weight loss can be challenging and may require a lot of diagnostic testing and time," Goukasian said. "But the important thing is that you're being proactive about your health and paying attention to your body."

SOURCE: UCLA Health, news release, Oct. 29, 2024