Choosing Oral Nutritional Supplements for Dysphagia: Selecting the Right Product

Oral nutritional supplements (ONS) are concentrated, nutritionally complete or nutrient-specific drinks and foods designed to increase caloric and protein intake in patients with inadequate dietary intake. For people with dysphagia on texture-modified diets — whose intake is often insufficient to meet nutritional requirements — ONS are a first-line dietetic intervention when food-based fortification alone is insufficient.

Selecting the right ONS for a person with dysphagia requires matching the product’s consistency to the prescribed IDDSI level, selecting the appropriate nutritional profile, and considering the person’s specific disease context, palatability preferences, and swallowing ability.

Why ONS Are Important in Dysphagia

People with dysphagia on texture-modified diets frequently cannot meet their energy and protein requirements through modified food alone. The reasons are discussed in detail in our article on malnutrition screening in dysphagia. In summary:

• Texture modification reduces caloric density.
• Modified foods are less palatable and consumed in smaller volumes.
• Mealtimes are longer and more effortful; fatigue limits intake.
• Underlying conditions (cancer, stroke, neurodegeneration) increase metabolic demand or reduce appetite.

NICE guideline CG32 (Nutrition Support in Adults) — the precursor to and companion of NICE guideline CG162 — specifies that oral nutritional support should be offered to patients at medium or high risk of malnutrition (MUST score ≥1) as a first-line intervention when dietary modification alone is insufficient.

IDDSI Consistency: The Primary Selection Criterion

The first question when selecting an ONS for a person with dysphagia is: at what IDDSI level is the liquid prescribed?

Standard liquid ONS at IDDSI Level 0 (Thin)

The majority of commercially available ONS in liquid form (e.g., most Ensure, Fortisip, Fresubin products) are naturally at IDDSI Level 0 Thin. These are appropriate only if:

• The person is prescribed Level 0 (no liquid thickening restriction), or
• The product is thickened by the caregiver or kitchen to the prescribed IDDSI level before serving.

Thickening standard ONS: Most liquid ONS can be thickened with a xanthan gum-based thickener. Starch-based thickeners interact poorly with high-protein liquids (the amylase in saliva degrades starch, and the protein content can interfere with starch hydration). Always verify the final IDDSI level with the syringe flow test after adding thickener, as high-protein and high-calorie liquids behave differently from plain water.

Pre-thickened ONS (IDDSI Levels 1–4)

Several manufacturers produce pre-thickened ONS specifically for dysphagia:

• Fortisip Compact Protein (Nutricia): Available as a standard thin liquid; higher caloric density than standard variants.
• Thick & Easy Hydrolyte (Fresenius Kabi) and similar products: Designed for pre-thickened oral hydration at specific IDDSI levels — relevant for fluid intake supplementation.
• Resource ThickenUp Clear with added nutrition: Some centres use hydration solutions thickened with clarity thickeners.

Verify IDDSI level on every batch: Even pre-thickened products can vary slightly between flavours, storage temperatures, and production batches. Test with the syringe flow test before serving.

Semi-solid ONS (IDDSI Level 4)

Several products are formulated as semi-solid (purée consistency) supplements:

• Nutilis Fruit (Nutricia): A fruit purée nutritional supplement at approximately Level 4; provides concentrated calories in a dessert format.
• Nutilis Complete (Nutricia): Powder that forms a Level 4 nutritionally complete supplement when made up.
• Thick & Easy Pre-Thickened Supplements (Fresenius Kabi): Various flavours at Level 3–4.

These are particularly useful for patients who categorically refuse liquid ONS but accept dessert-consistency foods.

Nutritional Profile Selection

Once IDDSI compatibility is confirmed, select the nutritional profile based on the patient’s clinical requirements:

Standard high-energy ONS (1.5 kcal/mL)

• For: General malnutrition risk with moderate intake reduction.
• Examples: Ensure Plus, Fortisip Standard 200 mL carton.
• Per serving (200 mL): ~300 kcal, 12–14 g protein.

High-energy, high-protein ONS (2 kcal/mL, ≥18 g protein per 200 mL)

• For: Significant protein depletion; post-surgical healing; sarcopenic dysphagia.
• Examples: Fortisip Compact Protein (125 mL providing 300 kcal, 18 g protein).
• Advantage: Smaller volume provides equivalent nutrition — important when volume tolerance is a barrier.

Renal-formula ONS

• For: Patients with chronic kidney disease requiring protein and electrolyte restriction.
• Critical consideration: Standard high-protein ONS are contraindicated in CKD patients not on dialysis. The renal dietitian must specify the appropriate product.

Diabetes-specific ONS

• For: Diabetic patients who require nutritional support but have poor glycaemic control.
• Feature: Modified carbohydrate profile with lower glycaemic index; helps reduce post-supplement hyperglycaemia.

Disease-specific ONS

• Oncology formulas: Often contain additional omega-3 EPA (e.g., Prosure), arginine, or immunonutrients — relevant for head-and-neck cancer patients with dysphagia.
• Hepatic formulas: BCAA-enriched; for hepatic encephalopathy with impaired protein metabolism.

Karen Chan and colleagues at the HKU Swallowing Research Laboratory have emphasised in clinical publications that ONS selection in dysphagia management requires the ASHA adult dysphagia portal standard of interdisciplinary coordination — the SLP determines IDDSI level, the dietitian selects the nutritional formulation, and the caregiver or kitchen implements both.

Palatability and Compliance

ONS compliance is frequently poor: published studies indicate that 30–50% of prescribed ONS is wasted when patients self-administer. The primary reasons are taste fatigue and inappropriate temperature/presentation.

Strategies to improve compliance:

• Flavour rotation: Provide a rotation of flavours to prevent taste fatigue.
• Correct temperature: Many patients prefer ONS chilled (3–5°C); some prefer room temperature. Ask and accommodate.
• Appropriate timing: ONS are most effective when taken between meals, not immediately before — pre-meal supplementation suppresses appetite for the meal.
• Small volumes: 125 mL compact formats are often better tolerated than 200 mL standard cartons.

Monitoring ONS Effectiveness

ONS should be monitored for:

• Consumption compliance: Percentage of prescribed ONS actually consumed per day.
• Weight trajectory: ONS should stabilise or improve weight — if weight continues to decline after 4 weeks of ONS, escalate to enteral nutrition review.
• Tolerance: GI symptoms (nausea, diarrhoea) may require formulation change.
• IDDSI compliance: Re-test liquid ONS after thickening on each shift.

Document ONS prescribing, compliance, and weight changes in the care record per NICE CG162 standards.

Key Takeaways

• Most liquid ONS are naturally at IDDSI Level 0 — thicken with xanthan-based thickener to the prescribed level.
• Pre-thickened and semi-solid (Level 4) ONS are available for patients requiring modified consistency.
• Select the nutritional profile (standard, high-protein, renal, diabetic, disease-specific) based on the clinical context.
• Compact high-energy/high-protein formats (125 mL) are better tolerated when volume is a barrier.
• ONS given between meals; monitor compliance and weight monthly.

References

1. Cichero JAY et al. (2017). Development of International Terminology and Definitions for Texture-Modified Foods and Thickened Fluids Used in Dysphagia Management. Dysphagia. PMID 26315994
2. IDDSI (2019). Complete IDDSI Framework. https://www.iddsi.org/framework
3. American Speech-Language-Hearing Association. Adult Dysphagia. https://www.asha.org/practice-portal/clinical-topics/adult-dysphagia/
4. NICE (2013, updated 2017). Intravenous fluid therapy in adults in hospital (CG162). https://www.nice.org.uk/guidance/cg162