Nearly one in five US adults now say they have used a GLP-1 drug at some point, according to a KFF poll, while 12% are currently taking one.1
ING estimates that at least 2% of adults across Europe and the UK are currently using GLP-1s, approximately nine to 10 million people, with that number potentially climbing as oral formulations increase uptake.2
The scale of GLP-1 use is bringing new nutritional questions into focus. A drug class capable of driving double-digit percentage weight loss can substantially reduce food intake, changing the nutritional challenges patients face during treatment and potentially beyond it.
That is because the same appetite suppression driving the headline results of GLP-1s is creating a quieter issue underneath the topline weight-loss figures. A significant share of that weight loss can come from lean mass rather than just fat, while substantially reduced food intake raises questions about whether some patients may struggle to meet their needs for protein and other nutrients.
As clinical and formulation attention shifts from simply how much weight patients lose to what kind, the question of how to support muscle health throughout GLP-1 therapy is becoming one of the more pressing conversations in nutrition science. Alongside established strategies such as adequate protein intake and resistance exercise, omega-3 fatty acids are being investigated for their potential to support muscle health and help preserve lean mass during weight loss.
The GLP-1 nutritional squeeze
GLP-1s work by suppressing appetite, and that mechanism is central to their effectiveness. Patients on these medications have been shown to consume 16 to 39% fewer calories than before starting treatment.3 Gastrointestinal side effects, including nausea, early satiety and slower gastric emptying, add a further layer of difficulty around eating enough to meet nutritional requirements, or eating a varied enough diet.
Reduced intake affects total nutrition, but muscle mass is where the impact has drawn the most attention. Research suggests that around 20% to 50% of weight lost during GLP-1 treatment may comprise lean body mass.4 This has prompted dietitians, formulators and pharmaceutical companies alike to look more closely at what patients need nutritionally to protect muscle while losing weight quickly.
Protein has understandably become the focal point of that response. However, with appetite suppressed and food volume down, patients may also be at risk of inadequate intake of protein, vitamins, minerals and other essential nutrients, even when weight loss itself is tracking as expected.4 This is leading to deeper questions being asked on what ‘complete’ nutrition should look like when individuals are taking GLP-1s.
Protein and exercise remain foundational
None of this changes the fundamentals of muscle preservation during weight loss. Higher protein intake, with targets commonly proposed around 1.2g to 2g per kg per day during active weight reduction, combined with resistance training, is among the best-supported strategies for protecting lean mass during any period of energy restriction.5
Clinical guidance for GLP-1 patients has largely reinforced that message, with dietitians and obesity medicine specialists prioritising protein intake and strength training as first-line advice.
The difficulty is putting that guidance into practice. Patients dealing with suppressed appetite and gastrointestinal side effects can struggle to reach recommended protein targets through food alone, and reduced intake elsewhere in the diet compounds the problem.
That gap between recommendation and reality is what is driving interest in additional nutritional support, including ingredients like omega-3 fatty acids, which can work alongside protein and exercise rather than replace them.
Where omega-3 fits in
The interest in omega-3 fatty acids and muscle health predates the GLP-1 boom by well over a decade. The two long-chain omega-3s most relevant to this discussion are docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), both found predominantly in oily fish and fish oil. The theory is that these fatty acids do not just sit passively in the diet. Once consumed, they can be incorporated into skeletal-muscle membranes, where research suggests they may influence signalling pathways involved in muscle protein synthesis and breakdown.
A review of the underlying biology has linked DHA and EPA incorporation into skeletal-muscle membranes with changes in anabolic signalling and muscle protein turnover.6
On the clinical side, a randomized controlled trial in older adults found that omega-3 supplementation enhanced the muscle protein synthesis response to amino acids and insulin, helping the body make more effective use of the protein it does receive.7 While this study was not conducted in people taking GLP-1 medications, it provides clinical evidence that omega-3 may influence muscle protein synthesis in older adults.
A 2020 meta-analysis of 10 randomized controlled trials in 552 older adults found that omega-3 supplementation was associated with a small but statistically significant gain in muscle mass compared with control groups, with a larger effect seen among participants taking more than 2g per day.8 The analysis also reported improvements in some measures of physical performance.
A 2023 systematic review of 21 intervention studies in adults examined omega-3 in a range of formats, including formulations combining omega-3 with protein, leucine and vitamin D, as well as products incorporating omega-3 into enteral nutrition. The review found that a substantial number of individual studies suggested potential benefits for maintaining or gaining muscle mass.9
The findings also point to omega-3 being studied as part of broader nutritional strategies, rather than solely as a standalone supplement. This is a relevant consideration when thinking about the nutritional needs of people taking GLP-1s.
The formulation challenge
Though research into omega-3’s role in muscle health continues to grow, getting the supplement into a product that patients will actually take consistently is its own challenge. Fish oil’s sensory drawbacks are well documented: oxidation, a fishy aftertaste and lingering odor have long limited its use in everyday formats like powders, shakes and stick packs.
A capsule regimen is one more thing to remember on top of medication schedules, appetite changes and gastrointestinal (GI) symptoms, and for many patients that is a barrier to consistent use.
This is the problem microencapsulation is designed to solve. The process coats the omega-3 oil in a protective layer, guarding against oxidation and masking taste and odor, which allows DHA and EPA to be built directly into palatable, nutrient-dense formats rather than confined to capsules. This innovation simplifies omega-3 fortification in nutrient dense food and beverage applications.
For manufacturers, the opportunity is not to position omega-3 as a replacement for protein or resistance exercise, but as a complementary nutritional strategy within a broader approach to muscle health during GLP-1-supported weight management. As research continues to explore how DHA and EPA may influence muscle protein metabolism, omega-3 is emerging as an area of interest alongside the more established foundations of adequate protein intake and resistance exercise.
The challenge is translating that science into products that consumers can realistically incorporate into their daily routines. Microencapsulation can help address some of the sensory and stability challenges associated with omega-3, opening up opportunities to deliver DHA and EPA in convenient formats.
For formulators responding to the nutritional demands of the growing GLP-1 market, combining established nutritional strategies with emerging ingredients and practical delivery formats could become an increasingly important part of the conversation.
References
- KFF. Poll: 1 in 8 Adults Say They Are Currently Taking a GLP-1 Drug for Weight Loss, Diabetes or Another Condition, Even as Half Say the Drugs Are Difficult to Afford.
- ING. Transformative or overhyped? The impact of weight-loss drugs on European food demand.
- Christensen, S.; et al. Dietary intake by patients taking GLP-1 and dual GIP/GLP-1 receptor agonists: a narrative review and discussion of research needs. Obes Pillars. 2024;11:100121.
- Johnson, BVB.; et al. Dietary supplement considerations during glucagon-like Peptide-1 receptor agonist treatment: a narrative review. Obes Pillars. 2025;16:100209.
- Mozaffarian, D.; 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. Am J Clin Nutr. 2025;122(1):344-367.
- McGlory, C.; et al. The influence of omega-3 fatty acids on skeletal muscle protein turnover in health, disuse, and disease. Front Nutr. 2019;6:144.
- Smith, GI.; et al. Dietary omega-3 fatty acid supplementation increases the rate of muscle protein synthesis in older adults: a randomized controlled trial. Am J Clin Nutr. 2011;93(2):402-412.
- Huang, YH.; et al. Effects of omega-3 fatty acids on muscle mass, muscle strength and muscle performance among the elderly: a meta-analysis. Nutrients. 2020;12(12):3739.
- Moon, GK.; et al. Effects of omega-3 fatty acid supplementation on skeletal muscle mass and strength in adults: a systematic review. Clin Nutr Res. 2023;12(4):304-319.