Written by Olivia Farrow, RD, MHSc
Reviewed by Krista Kolodziejzyk, RD, MPH, MBA and Maria Dellanina, RDN
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If you are a dietitian working in client nutrition counseling, chances are you’ve had at least one client mention GLP-1 medications in the past few months. Whether it’s Ozempic®, Wegovy®, or Mounjaro®, these medications are showing up everywhere.
And with their growing popularity comes a new set of challenges for dietitians. Clients starting GLP-1 or dual GIP/GLP-1 therapies often experience major changes in appetite, fullness and digestion. Some report that they forget to eat or can only tolerate a few bites at a time. Others struggle with side effects like nausea, constipation, or fatigue. Over time, these changes can make it difficult to meet energy and nutrient needs, maintain lean mass, or build sustainable habits around food.
This is why dietitian support is essential. GLP-1 medications may alter how clients eat, but nutrition care determines how well they adapt. Dietitians play a critical role in monitoring adequacy, preventing muscle loss, managing gastrointestinal symptoms, and supporting a healthy relationship with food throughout treatment (Mozaffarian, 2025). Outcomes from GLP-1 therapy are best when paired with ongoing dietitian counseling and lifestyle support (Gigliotti et al., 2025).
As these medications become more common, clients will increasingly look to dietitians for guidance, not just on what to eat, but on how to stay nourished and confident when hunger cues, meal patterns, and body composition start to shift.
How GLP-1 Medications Work
GLP-1 medications mimic a natural hormone called glucagon-like peptide-1 (GLP-1), one of the body’s built-in signals that helps regulate appetite and blood sugar.
After we eat, GLP-1 is released from the gut and tells the brain, “You’re satiated.”
It also helps the pancreas release insulin, slows down how quickly food leaves the stomach, and reduces glucagon (a hormone that raises blood sugar). The result? People feel satisfied sooner and eat less overall (Mozaffarian, 2025).
Dual GIP/GLP-1 receptor agonists, like tirzepatide, take this one step further. They activate both GLP-1 and another hormone called GIP (glucose-dependent insulinotropic polypeptide). Together, these hormones strengthen blood sugar control and amplify fullness signals in the brain (Mozaffarian, 2025).
Because these medications reduce appetite and slow digestion, they often lead to lower calorie intake and weight loss. But the same mechanisms can also make it harder to eat enough protein or maintain muscle mass over time, which in turn can reduce resting metabolic rate, a key reason why nutrition care is so important for clients using GLP-1s.
The Nutrition Challenges Dietitians Need to Address
While GLP-1 medications are effective for appetite control and weight reduction, they also change how clients experience food. By slowing gastric emptying and suppressing hunger signals, these drugs often lead to much smaller meal volumes and longer gaps between eating. For some clients, this can feel like a relief from constant hunger. For others, it can quickly turn into unintentional under-eating.
When overall intake drops, so does protein, fiber, and micronutrient consumption. Over time, this can lead to:
- Loss of lean body mass and lower resting metabolic rate
- Reduced protein intake, making it harder to maintain muscle
- Micronutrient deficiencies, particularly vitamin D, calcium, magnesium, and B-vitamins
- Lower energy levels and slower recovery from illness or exercise (Mozaffarian, 2025)
Gastrointestinal side effects can make the picture even more complex. Nausea, constipation, bloating, reflux, and early satiety are some of the most common complaints, especially during dose escalation. These symptoms can further reduce appetite and limit diet variety (Mozaffarian, 2025).
This is where dietitians play a vital role. Ongoing nutrition counseling helps clients (Mozaffarian, 2025; Gigliotti et al., 2025):
- Adapt to changing hunger cues and find a sustainable eating rhythm
- Manage GI symptoms through pacing, hydration, and fiber adjustments
- Understand the importance of resistance exercise and protein intake to preserve muscle mass and prevent excessive metabolic slowdown
- Stay nourished while balancing medication side effects and real-life routines
Regular follow-up is key. Small adjustments can make the difference between short-term success and long-term sustainability.
Looking for ready-to-use tools to support your clients on GLP-1 therapy? Inside the DSC Practitioner Membership, you’ll get access to 350+ editable client handouts, including our brand-new GLP-1 Nutrition handout. It’s designed to help clients understand the foundations of how to eat well when taking a GLP-1.
Join the DSC Practitioner Membership today and get instant access to our full library of evidence-based handouts, templates, and counseling tools.
Guiding Principles of GLP-1 Nutrition
GLP-1 medications work best when nutrition care focuses on adequacy, tolerance, and long-term sustainability. These principles can guide your counseling and help clients stay well nourished throughout treatment (Mozaffarian, 2025, Gigliotti et al., 2025):
- Maintain nutritional adequacy
Even with smaller portions, clients still need enough calories, protein, and micronutrients to support metabolic health. Ensuring adequate intake helps reduce fatigue, protect muscle, and maintain resting energy expenditure during active weight loss. - Preserve lean mass
Loss of lean body mass contributes to declines in resting metabolic rate and strength. Supporting muscle through adequate protein intake and resistance-based activity promotes metabolic stability and may reduce weight regain risk once the medication is stopped. - Support tolerance and GI comfort
Nausea, bloating, constipation, and reflux are common during initiation and dose escalation. Adjusting meal timing, pacing, and fiber intake can help manage symptoms while maintaining hydration and nutrient adequacy. Regular follow-up allows dietitians to spot patterns early and adapt care as needed. - Monitor micronutrient status
Smaller meal volumes can reduce intake of key vitamins and minerals. Pay attention to vitamin D, calcium, magnesium, iron, and B-vitamins. For some clients, short-term or ongoing supplementation may be needed to maintain adequacy. - Encourage physical activity
Combining GLP-1 therapy with physical activity supports outcomes beyond weight change. Resistance training helps maintain lean mass, improves insulin sensitivity, and contributes to overall well-being. Additionally, consider discussing pre-exercise nutrition with clients to ensure energy levels are sufficient for physical activity. - Normalize plateaus and transitions
Metabolic adaptation and hormonal shifts make weight plateaus or partial regain after discontinuation expected, not concerning. Reframing these phases as part of normal physiology helps clients stay engaged and confident in their progress.
The Dietitian’s Role in GLP-1 Nutrition Care
GLP-1 therapy works best when paired with nutrition counseling and behavior support (Gigliotti et al., 2025). Clients benefit from education on hunger and fullness cues, reassurance that reduced appetite is expected, and structured follow-up to maintain adequate intake.
Dietitians can also help manage the transition off medication, guiding clients through appetite changes and adjusting nutrition plans to prevent rapid rebound or nutrient depletion.
In short, the role of the dietitian in GLP-1 Nutrition is not to control intake, but to ensure nourishment, preserve health, and empower clients to sustain progress beyond the medication itself.
Are your clients asking about Ozempic? Are you hearing colleagues debate the risks vs. benefits of incretin-based therapy (GLP-1, GIP)? Are you feeling stuck somewhere in the middle?
Key Takeaways
- GLP-1 nutrition focuses on adequacy, not restriction.
- Protein, hydration, and resistance exercise are essential to preserve lean mass and metabolic health.
- Managing GI symptoms and monitoring micronutrient intake supports tolerance and adherence.
- Weight plateaus and appetite changes are physiological, not behavioral, failures.
- Dietitian-led follow-up is critical for safe, sustainable outcomes throughout all phases of GLP-1 therapy (Mozaffarian, 2025).
Meet all of your professional development needs and access to 300+ client handouts with a Dietitian Success Center membership. Get started for free! Access your DSC starter kit and join a supportive community of dietitians today.
References
- Mozaffarian D, Agarwal M, Aggarwal M, Alexander L, Apovian CM, et al. Nutritional priorities to support GLP-1 therapy for obesity: A joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society. Obesity (Silver Spring). 2025;33(8):1475–1503.
- Gigliotti L, Warshaw H, Evert A, Dawkins C, Schwartz J, Susie C, Kushner R, Subramanian S, Handu D, Rozga M. Incretin-Based Therapies and Lifestyle Interventions: The Evolving Role of Registered Dietitian Nutritionists in Obesity Care. J Acad Nutr Diet. 2025 Mar;125(3):408-421. doi: 10.1016/j.jand.2024.10.023. Epub 2024 Nov 7. PMID: 39521378.
