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Use of popular weight-loss drugs can lead to malnutrition, and in extreme cases can cause scurvy, a disease common among sailors hundreds of years ago.
Scurvy is a nutritional disorder caused by long-term, severe Vitamin C deficiency. Left untreated, it can cause fatigue, bleeding gums, tooth loss, skin hemorrhaging and more. In serious cases, it can be fatal.
British pop star Robbie Williams revealed last year that he suffers from a “17th century pirate disease” and failing eyesight. He linked the conditions to years of using weight-loss drugs, the New York Post reported.
Williams’ story is back in the news after Swedish and Australian researchers published a systematic review linking GLP-1 drugs to malnutrition.
GLP-1s, including Saxenda, Wegovy, Mounjaro and Ozempic, can help with weight loss. However, studies also link them to serious side effects.
Side effects include gastrointestinal problems, acute pancreatitis, higher rates of gallbladder and biliary disease, kidney stones, arthritis, sleep disturbances, dental decay, hair loss, and loss of bone density and muscle mass. The drugs may also be linked to cancer.
Clinical guidelines ignore risk of malnutrition
The new review on malnutrition and GLP-1s builds on a July op-ed in The BMJ by U.K. general practitioner Dr. Ellen Fallows. She noted that most research on the drugs fails to examine links to serious nutritional complications.
Known complications include severe thiamine deficiency, which can cause Wernicke encephalopathy and lead to irreversible dementia. There have also been cases of metabolic acidosis linked with extreme appetite suppression and critically low magnesium levels.
Adverse event reporting systems have also recorded cases of “starvation” and dangerously low blood glucose levels, she wrote.
In one clinical trial, participants taking tirzepatide, sold as Zepbound, cut their daily intake to about 800 calories for long periods. At such low levels, getting enough macronutrients and micronutrients is very difficult without medically designed meal replacements.
Current clinical guidelines don’t clearly highlight the risks of malnutrition with this level of calorie restriction, Fallows said.
Both recent papers argue that nutrition is a major blind spot in GLP-1 side effect studies. This has serious implications for the drug’s clinical use.
Reduction in body weight doesn’t equal health
Little is known about how the drugs affect what people eat. Unknowns include whether people’s vitamin intake is sufficient, and whether the weight loss from the drugs is linked to nutritional health and long-term well-being, the systematic review authors reported.
“A reduction in body weight does not automatically mean the person is well nourished or healthy,” said Clare Collins, professor of Nutrition and Dietetics at the University of Newcastle, who led the study. “Nutrition plays a critical role in health, and right now it’s largely missing from the evidence.”
Given the evidence of serious nutritional impact, “we need to ensure we are not throwing the baby out with the bath water,” she added.
The review examined 41 randomized controlled studies of the drugs conducted over the last 17 years. The studies enrolled over 50,000 participants.
Only two studies assessed changes in dietary intake as an outcome, and one of those studies was unpublished. Both found that people taking the drugs reduced their total energy intake. The drugs also changed the distribution of the fat, protein and carbohydrates they consumed.
The review assessed the quality of the two studies as “poor” and “acceptable.” “These results highlight a critical gap in the literature,” the authors concluded.
Most clinical trials measure weight loss, which is an easy outcome to assess. Few have measured participants’ nutritional status or dietary quality before and after treatment.
Without strong dietary data, clinicians and researchers can’t properly understand the wider effects of medications, the researchers said. They also can’t give appropriate advice on how to use them.
“When people are eating less, the quality of what they eat matters even more,” Collins said. “If someone loses weight but their diet lacks adequate protein, fibre, vitamins or minerals, that has major concerns for their long-term muscle mass, bone health, brain health, gut health, as well as skin integrity and overall wellbeing.”
Collins said that factors such as weight and blood sugar provide only part of the picture.
“Diet quality, food patterns and nutrient intake all contribute to health. They should be measured with the same rigour as other clinical outcomes,” she said.
Nutritional effects may hit economically disadvantaged harder
The results from controlled studies might not reflect real-world outcomes. This is especially true for people who are nutritionally vulnerable or facing food poverty, Fallows wrote.
Many people with obesity already rely on inexpensive, calorie-dense but nutrient-poor foods. Powerful drugs can greatly reduce appetite. This may lower total calorie intake, but it also reduces intake of essential vitamins, minerals and protein.
The result could worsen what experts call the “double-burden of malnutrition.” This means obesity could happen alongside muscle loss and a lack of micronutrients.
Prescribing these drugs should involve more than basic dietary advice, Fallows argued. Clinicians should assess nutritional status before starting treatment. They also need to provide ongoing monitoring and support.
Broader public health solutions may also be necessary.
The paper suggests that programs — like food vouchers or “food on prescription” programs that provide access to high-quality, nutrient-rich foods — could reduce risk.
Until more research clarifies the risks and best practices, Fallows urged a careful rollout of the medications.
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What are the implications for children?
The two studies that examined nutrition only targeted adults. Yet, in the U.S., more than 14 million children and teenagers — roughly 1 in 5 — are affected by obesity.
Since the American Academy of Pediatrics (AAP) released new clinical guidelines for treating childhood obesity in January 2023, prescriptions for weight-loss drugs for children have skyrocketed.
However, finding studies on the nutritional effects of GLP-1s in children and teenagers is challenging. Doctors warn that children who are prescribed these drugs need careful monitoring so they don’t suffer from nutrition and hydration deficits.
Dr. Dan Cooper, a pediatrician and obesity researcher from the University of California, Irvine, told AAMCNews that nutritional concerns are higher in these age groups.
“Caloric intake impacts the production of growth hormones, bone building, and puberty,” he said. “The biological clock of development is quite detailed, delicate, and not completely understood. We need to be careful about altering those processes in young people.”
Related articles in The Defender- Can Weight-Loss Drugs Cause Cancer? The Data Are Mixed
- ‘Their Rubber Stamp Is Reckless’: After AAP Endorses Weight-Loss Drugs for Kids, Prescriptions Soar
- Eli Lilly’s Weight Loss Drug Contributed to Nurse’s Death
- Weight-loss Drug Prescriptions for Kids and Teens Soar Despite No Safety Data
- Childhood Obesity: Drugs and Surgery Top List of American Academy of Pediatrics New Guidelines
- GLP-1 ‘Skinny Jabs’: Rapid Weight Loss, But at What Cost?
- ‘Ozempic Teeth’: Patients Using GLP-1 Drugs Report Surge in Dental Decay
