In clinical and senior nutrition, the real problem is not always how much protein goes into the bottle – it’s whether older patients are willing to finish it. Thick, chalky or “medical-tasting” drinks are often left half-full, no matter how carefully they were formulated. For seniors, taste and texture decide adherence long before claims or guidelines do – and that’s exactly where native micellar casein can change the game. This article looks at the issue from a manufacturer’s point of view: why so many high-protein drinks are only partly consumed, and how formulating with native micellar casein can help create patient-friendly ONS that are both nutritionally effective and genuinely pleasant to drink.
The quiet problem of half-finished bottles
The global oral clinical nutrition supplement market is expanding steadily — driven by ageing populations, chronic disease and rising awareness of disease-related malnutrition. Recent analyses estimate the market at around USD 16–18 billion in 2024, with annual growth of roughly 5–7% expected through 2030. [1]
Yet at ward level, dietitians and nurses see a more uncomfortable reality: a significant proportion of prescribed ONS is not fully consumed.
Recent work on ONS adherence shows that intake often falls well below prescribed levels, with adherence commonly defined as the ratio of actual intake to the recommended amount. Reasons for poor adherence include: [2]
- Palatability issues (too sweet, too artificial, “medical” taste)
- Texture problems (too thick, chalky, “coating” sensation)
- Volume and flavor fatigue (large portions, limited variety)
- Psychological associations with end-of-life care (“this is for very sick people, not for me”) [3]
Several recent reviews and clinical evaluations confirm the downstream impact: poor adherence to ONS is associated with worse clinical outcomes, more complications and higher rates of rehospitalisation in older patients. [4]
For manufacturers, this is a clear business and medical signal: a product that is technically perfect but left half-full is underperforming — for patients, for clinicians and for brands.
Why adherence matters more than theoretical protein targets
Scientific societies now converge on the idea that most older adults, especially those with illness or frailty, need more protein than the traditional 0.8 g/kg/day. Recent expert discussions suggest targets of 1.0–1.2 g/kg/day for healthy older people, and up to 1.5 g/kg/day in case of acute or chronic disease and risk of malnutrition. [5]
ONS are often prescribed to bridge the gap between theoretical requirements and real-world intake. But if a drink delivers 20 g of high-quality protein on the label and only 50–60% of it is actually consumed, the effective protein intake is much lower.
From a Business perspective, that creates a triple tension:
- Medical: suboptimal protein intake means sarcopenia, delayed recovery and longer stays.
- Economic: institutions and payers pay for products that partly end up in the bin.
- Reputational: brands are associated with “unappealing” or “too heavy” products that staff struggle to encourage.
In other words, adherence — not just formulation — is now a competitive advantage in clinical and senior nutrition.
Where texture goes wrong in high-protein UHT drinks
Formulating oral clinical nutrition products is technically demanding:
- Protein levels are high (often >10% of energy).
- Products must be shelf-stable, frequently UHT-processed.
- Volumes should remain manageable, especially for patients with low appetite.
Under these constraints, it’s not surprising that many formulas drift towards one of two extremes:
1- Too thick, almost pudding-like
- Difficult to swallow for frail patients
- Perceived as “heavy”, leading to early satiety and incomplete consumption
2- Thin but unstable
- Sedimentation, phase separation or “grainy” mouthfeel over shelf life
- Visual defects and texture changes that erode trust
Heat treatment at high protein concentrations can promote viscosity increase, gelation and sedimentation, especially when the protein system and process parameters are not optimised. Technical reviews of shelf-stable dairy protein beverages highlight the delicate balance between protein type, concentration, pH and processing conditions needed to keep high-protein drinks both stable and drinkable. [6]
For older adults and patients, these physical issues quickly translate into sensory rejection: “too thick”, “chalky”, “sticks in the throat”.
Native micellar casein: a different starting point for high-protein drinks
This is where native micellar casein becomes strategically interesting for clinical and senior formulas.
Micellar casein is the main protein fraction in milk. When it is isolated gently — via membrane filtration directly from milk — its native micellar structure is preserved. This structure is particularly well suited to neutral pH, shelf-stable beverages, which is why micellar casein concentrates and isolates are now widely used as protein sources in long-life dairy and medical nutrition drinks. [6]
In practice, for oral clinical nutrition, native micellar casein offers manufacturers three key levers:
1- High protein with manageable viscosity
- Formulated correctly, micellar casein systems allow high protein levels while keeping a drinkable, smooth texture, rather than a spoonable gel. [7]
2-Good suspension and stability in UHT drinks
- Micellar structures can help limit sedimentation and phase separation in neutral pH beverages, supporting a consistent mouthfeel over shelf life. [6]
3-Natural whitening and sensory profile
- Micellar casein contributes to the creamy, white appearance expected from dairy-based oral supplements, and provides a good base for flavour systems without aggressive off-notes. [7]
The commercial environment is moving in the same direction: recent micellar casein market analyses consistently highlight ready-to-drink beverages and clinical nutrition as key growth segments, with micellar casein isolate specifically promoted as a solution for protein malnutrition and high-protein medical foods. [8]
For brands, native micellar casein is not just “another dairy protein” — it is a platform ingredient that can help reconcile:
- High protein density
- Acceptable viscosity
- Long shelf life
- And “comforting” sensory cues for seniors and patients
Designing patient-friendly high-protein drinks
What does this mean concretely for your next clinical or senior RTD launch?
1. Start from the patient, not the lab.
Recent reviews on ONS adherence emphasise that palatability, texture, portion size and variety are among the strongest drivers of intake in older adults.
Questions to ask early:
- Can a frail 80-year-old realistically finish this volume?
- Does the viscosity feel “reassuringly creamy” or “too thick to bother”?
- Is the sweetness appropriate for someone with low appetite or taste changes?
2. Use native micellar casein as the backbone of UHT formulas.
By building the protein system around native micellar casein — and, where relevant, combining it with other proteins — you can:
- Reach target protein levels in a sippable beverage
- Limit sedimentation and gelation risks over shelf life
- Reduce the need for multiple stabilisers, which supports cleaner labels and simpler recipes [7]
3. Optimise “sensory adherence”, not just nutritional specs.
Think like a clinician and a sensory scientist at the same time:
- Texture and viscosity tailored to the target group (e.g. mild thickening for dysphagia vs standard drinks for mobile seniors)
- Balanced sweetness and flavour intensity to avoid fatigue
- Appropriate portion sizes (energy and protein density vs volume)
In a recent study, better tailoring of ONS to patients’ sensory preferences and habits was associated with improved intake and reduced complications in older patients. [4]
The business case for better texture
For manufacturers, investing in native micellar casein-based, patient-friendly formulations is not just a scientific choice — it is a strategic one.
- Better adherence = better outcomes
When more of the prescribed protein is actually consumed, clinical teams see improved nutritional status, fewer complications and shorter hospital stays. [4] - Less waste = better economics
Every half-finished bottle represents lost product, lost margin and lost trust from institutions and payers. - Better experience = stronger brands
When patients and seniors perceive a drink as pleasant, comforting and easy to finish, they are more likely to accept it as part of daily routine — even outside hospital settings.
In a market where clinical nutrition is growing and competition is increasing, adherence-centric design is becoming a key differentiator. Native micellar casein gives manufacturers a powerful tool to align high protein density with the textures and sensory profiles that seniors and patients can actually live with.
FAQ – Native Micellar Casein & High-Protein Drinks for Seniors
1. Why do many seniors and patients struggle to finish protein drinks?
Older adults often experience reduced appetite, taste and smell changes, and swallowing difficulties. Very sweet, thick or chalky drinks quickly become unpleasant, leading to incomplete consumption and poor adherence. [3]
2. What is native micellar casein?
Native micellar casein is a milk protein ingredient obtained directly from fresh milk by gentle membrane filtration. This process preserves the natural micellar structure of casein, which is well suited to neutral pH, shelf-stable, high-protein beverages.
3. How does native micellar casein improve the texture of high-protein drinks?
Formulated correctly, native micellar casein helps deliver high protein levels in drinks that remain smooth and drinkable. It supports stable viscosity, good suspension and a creamy, familiar mouthfeel, which can improve acceptance among seniors and patients. [6]
4. Is native micellar casein suitable for UHT clinical beverages?
Yes. Micellar casein ingredients are widely used in UHT shelf-stable dairy and medical nutrition products because of their heat stability at neutral pH and their ability to maintain acceptable texture and stability over shelf life. [6]
5. Can native micellar casein be combined with other proteins?
It can be combined with other protein sources, such as whey, to balance rapid and sustained amino acid delivery while still benefiting from micellar casein’s functional properties in texture and stability. [8]
6. Why should clinical nutrition brands focus on sensory experience if their products are prescribed?
Even when prescribed, ONS only work if they are consumed. Studies show that poor palatability and texture are major barriers to adherence, and low adherence is linked with worse outcomes and higher rehospitalisation rates in older patients. [4]
Sources
[1] ResearchAndMarkets. Oral Clinical Nutrition Market – Global Industry Size, Share & Forecast to 2030. 2024. https://www.researchandmarkets.com/reports/5864734/oral-clinical-nutrition-market-global-industry
[2] Liu B. Definition and assessment of adherence to oral nutritional supplements in adults with malnutrition: a systematic review. 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11610086/
[3] Hetherington M.M. Barriers to oral nutritional supplement intake in older adults. Appetite. 2024. https://www.sciencedirect.com/science/article/pii/S0195666324001284
[4] Görünmezoğlu HÖ. Effectiveness of Oral Nutrition Supplements in Older Patients. GMJ. 2025. https://ifnmujournal.com/gmj/article/view/e-GMJ2025-A04
[5] Groenendijk I. Discussion on protein recommendations for supporting muscle mass and function in older adults. 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11150820/
[6] Singh R. Shelf-stable dairy protein beverages – ingredient and process considerations. 2022. (PDF via Semantic Scholar) https://pdfs.semanticscholar.org/8a25/66032db68adb42a1fc36ce0fb1eed98fb6ef.pdf
[7] D. Rovai, M.E. Watson, D.M. Barbano, M.A. Drake, Consumer acceptance of protein beverage ingredients: Less is more, Journal of Dairy Science, Volume 108, Issue 2,
2025, Pages 1392-1407, ISSN 0022-0302, https://doi.org/10.3168/jds.2024-25679. (https://www.sciencedirect.com/science/article/pii/S0022030224013006)
[8] Future Market Insights. Micellar Casein Market. 2025.
https://www.futuremarketinsights.com/reports/micellar-casein-market
