WASHINGTON (TNND) — Popular GLP-1 weight-loss medications have helped millions of people shed pounds, but new research from Australia suggests doctors and patients may need to pay closer attention to what users are actually eating while taking them.
A systematic review from the Hunter Medical Research Institute (HMRI) found that while the medications are effective for weight loss, many clinical trials fail to track changes in diet or whether patients are still getting enough essential nutrients. According to researchers, that gap could increase the risk of malnutrition over time.
One concern highlighted in the review is the potential for vitamin deficiencies — including rare cases of scurvy, a disease caused by a lack of vitamin C. Historically known as “pirate’s disease,” scurvy develops when the body doesn’t receive enough fruits and vegetables to maintain healthy tissue repair and immune function.
Symptoms can include anemia, loose teeth, bruising, bleeding under the skin, swollen or bleeding gums, and wounds that don’t heal.
Researchers stress that these cases appear uncommon and that the findings are not a call for people to stop taking GLP-1 medications. Instead, experts say the results point to a major blind spot in current research.
“Very little is known about the exact changes these medications have on what people actually eat, whether vitamin and mineral intakes are adequate, and whether weight-loss achieved through medication also supports optimal nutrition-related health and wellbeing in the long-term.” — Hunter Medical Research Institute
Doctors are now being urged to monitor patients’ diets more closely and ensure that even smaller meals remain nutritionally dense. The review also calls for future clinical trials to include detailed dietary assessments to better understand long-term health effects.
Beyond vitamin C, researchers say other deficiencies could also pose risks. Iron deficiency can lead to anemia, while low levels of certain B vitamins may contribute to serious neurological conditions such as Wernicke’s encephalopathy — though experts note these complications remain rare.
Another challenge, researchers say, is that symptoms of nutrient deficiency — including fatigue, nausea, and irritability — can overlap with the common side effects of GLP-1 medications, making problems harder to spot early.
For patients concerned about their nutritional status, experts recommend working with a registered dietitian and considering screening for deficiencies before starting treatment.
The bottom line from researchers: GLP-1 medications can be highly effective for weight loss, but long-term success depends not just on appetite suppression — it also requires careful nutrition management.