GLP-1 Weight Loss Drugs May Cause Nutrient Deficiencies: What You Need to Know
Weight loss medications like GLP-1 receptor agonists (GLP-1RAs), including popular drugs such as semaglutide and tirzepatide, are becoming widely used to help people manage obesity and improve blood sugar control. These drugs work by slowing down the digestive system and reducing appetite, which helps reduce calorie intake. However, a recent study published in Frontiers in Nutrition reveals some important concerns about nutrient intake in people using these medications.
Key Findings from the Study
The study examined 69 adults using GLP-1RAs for at least one month. Here’s what researchers found:
- Inadequate nutrient intake: Many participants did not meet recommended daily intakes for critical nutrients including vitamins D, A, C, E, and K; minerals like calcium, magnesium, potassium, iron, and choline; and dietary fiber.
- Protein intake concerns: Although protein made up an adequate percentage of total calories consumed, the amount per kilogram of body weight was often too low to support muscle preservation during weight loss. Only 43% met the minimum recommended protein intake (1.2–2.0 g/kg/day).
- Excess calories from fat and sodium: Participants consumed more saturated fat and sodium than recommended.
- Calorie intake mismatch: Average calorie intake (about 1,700–1,900 kcal/day) was higher than expert recommendations for people on GLP-1RA therapy, which typically suggest 1,200–1,500 kcal/day for women and 1,500–1,800 kcal/day for men.
- Dietary habits: Most participants ate fewer servings of fruits, vegetables, grains, and dairy than recommended by MyPlate guidelines.
Why Does This Matter?
Proper nutrition is essential during weight loss to:
- Preserve lean muscle mass
- Maintain bone density
- Support cardiovascular health
- Prevent vitamin and mineral deficiencies that can lead to fatigue, weakened immunity, or other health issues
GLP-1RAs can cause side effects like nausea and diarrhea, which may affect food preferences and lead to suboptimal nutrient intake. Slower gastrointestinal transit time may also impact nutrient absorption.
What Should Patients Using GLP-1RAs Do?
1. Seek Personalized Nutritional Guidance
Because GLP-1RA users have unique nutritional needs, working with a Registered Dietitian Nutritionist (RDN) or bariatric nutrition expert can help tailor meal plans that:
- Meet calorie goals appropriate for weight loss
- Ensure adequate protein intake (especially per body weight)
- Include sufficient vitamins and minerals through balanced food choices or supplements if necessary
2. Track Nutrient Intake Carefully
Keeping a food diary or using dietary tracking tools can help identify gaps in nutrient intake. Many participants in the study overestimated their fruit and vegetable consumption.
3. Focus on Nutrient-Dense Foods
Incorporate more:
- Fruits and vegetables
- Whole grains
- Low-fat dairy or fortified alternatives
- Lean protein sources such as lean meats, fish, legumes, and dairy
- Healthy fats in moderation
4. Discuss Supplement Use with Healthcare Providers
If diet alone cannot meet nutritional needs, safe supplementation may be recommended for vitamins D, calcium, iron, or others.
Takeaway
GLP-1 weight loss drugs are powerful tools for managing obesity but come with nutritional challenges that require attention. Optimizing nutrient intake alongside medication can support better health outcomes and long-term success.
At BeBetter Bariatrics, we understand the importance of comprehensive care that includes both medical treatment and nutrition support. If you are using or considering GLP-1RA therapy, contact us to learn how personalized nutrition counseling can help you achieve your weight loss goals safely and effectively.
References:
Johnson B et al., Investigating nutrient intake use glucagon-like peptide-1 receptor agonist: cross-sectional study, Frontiers in Nutrition, 2025.
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