Expert shares insight on GLP-1’s potential to cause a nutrition gap

GLP-1 use is gaining popularity, expanding the market opportunity for complementary nutritional products. As the weight-loss drug interferes with hunger cues, leading users to eat less overall, experts urge nutritional guidance to avoid micronutrient inefficiency, loss of lean muscle mass, and other potential long-term health impacts.

Nutrition Insight sits down with Ryan Kane, assistant professor at Tufts University School of Medicine, Boston, US, to discuss the role the popular weight loss drug has on malnutrition, long-term health effects, and the body’s nutritional intelligence.

“GLP-1s often reduce food cravings and dampen reward-driven eating, which can be beneficial for overeating but may also blunt biologically meaningful hunger cues. Relatedly, GLP-1s are often very effective at reducing patients’ intrusive ‘food noise,’ allowing more individual agency of what and when patients decide to eat.”

“However, due to the potential interference with patients’ intuitive hunger, structured nutritional counseling becomes even more important,” he adds.

GLP-1 and nutritional health

Regarding weight-loss drugs’ impact on nutritional intelligence, Kane says there is no clear data on specific innate nutrient cravings that patients lose when using GLP-1.

“GLP-1 medications often substantially reduce appetite, slow the digestive process, and alter food preferences. These changes typically improve overall cardiometabolic health but also result in significant changes to patients’ prior eating patterns.”

Many patients consume notably fewer overall calories, increasing the risk of inadequate nutritional intake if this is not intentionally monitored and addressed, he explains.

“With any rapid weight loss, such as from GLP-1 use or bariatric surgery, individuals may experience lean mass loss.”

Many patients consume notably fewer overall calories, increasing the risk of inadequate nutritional intake.He says this underscores the importance of pairing pharmacotherapy with evidence-based nutrition supports and physical activity, especially resistance exercise.

“Patients who use GLP-1 medications benefit from individualized counseling with multidisciplinary teams to facilitate improved overall nutritional health with these medications and mitigate the potential harms from their use.”

Long-term health effects

Kane says that long-term data on these medications continue to emerge, but current evidence suggests substantial benefits for obesity-related conditions, including type 2 diabetes, metabolic-associated steatohepatitis (liver disease), moderate to severe sleep apnea, and cardiovascular risk.

“There is emerging evidence for improved blood pressure, knee osteoarthritis pain, substance use, and several other conditions.”

Meanwhile, there are also health concerns, including loss of lean mass, potential micronutrient insufficiency, weight cycling through medication cessation with weight regain, and medication-related gastrointestinal side effects.

“There are also important unanswered questions about sustained use over several decades, which at this time are mostly related to variable long-term adherence and affordability issues. Ongoing monitoring and individualized care will be essential.”

Kane adds that GLP-1 medications slow gastric emptying and alter gastrointestinal motility, which can affect how and when nutrients are absorbed.

“While they do not appear to directly impair absorption in most patients, delayed digestion may influence the tolerance and bioavailability of certain nutrients. In some individuals, persistent constipation, nausea, or vomiting can further compromise intake. These effects highlight the need for tailored dietary strategies when side effects arise.”

Pharma intervening with nutrition

As access to GLP-1s grows, particularly in the US, the food and nutrition industries are exploring how to develop or adapt products tailored to the medication users.

Kane says GLP-1 medications can affect how and when nutrients are absorbed.The nutrition industry is increasingly recognizing that GLP-1 users have distinct dietary needs, particularly around protein to support lean mass and meal structure that favors small, more frequent nutrient-dense meals, explains Kane.

“We are seeing greater emphasis on medical nutrition therapy by dieticians, specialized supplements, and ‘GLP-1-friendly’ food products. Health systems and employers are also investing more in integrated nutrition services. This reflects a shift toward combining pharmacologic and nutritional care.”

He asserts that, concerningly, many of these marketed “high protein” products and GLP-1-focused supplements are capitalizing on the weight-loss market, yet pushing ultra-processed foods. In the long term, he argues they are more likely to cause harm than a whole-food-based approach.

Meanwhile, there is also a growing demand for high-quality, protein-rich, micronutrient-dense whole foods. “Products designed to support muscle preservation, hydration, and gastrointestinal comfort may be particularly helpful for patients,” highlights Kane.

“Evidence-based supplements and medically tailored meals may also play an important role, especially for patients who are time-limited for preparing whole food meals. Importantly, these products should be accessible and affordable, not limited to higher-income consumers.”

Kane concludes that GLP-1 medications are a powerful tool but not a substitute for comprehensive, person-centered care.

“Nutrition, social context, and long-term behavior change remain central to sustainable health outcomes,” he continues. “From an equity perspective, we must ensure that both medications and high-quality nutrition support are available to all patients who could benefit.”

“The future of obesity care lies in integrating pharmacological interventions with nutritious, affordable foods, education, and community-based resources.”