What are the IDDSI levels?

IDDSI defines 8 dietary levels numbered 0 to 7. Levels 0–4 describe liquid thickness (Thin to Extremely Thick) and Levels 3–7 describe food texture (Liquidised to Regular). Each level has objective test criteria to ensure consistency across settings.

How is IDDSI level determined?

IDDSI level is prescribed by a speech-language therapist following formal swallowing assessment, which may include bedside evaluation and/or instrumental assessment (VFSS or FEES). Do not self-prescribe an IDDSI level.

What is the IDDSI Flow Test?

The IDDSI Flow Test uses a standard 10 mL syringe filled with the liquid to be tested. After 10 seconds of free drainage, the volume remaining in the syringe determines the IDDSI liquid level: ≤1 mL = Level 0, 1–4 mL = Level 1, 4–8 mL = Level 2, >8 mL = Level 3 or above.

Which IDDSI level is honey thick?

Under IDDSI, the old term 'honey thick' approximately corresponds to Level 3 (Moderately Thick). However, IDDSI replaced imprecise food-descriptor terminology with objective test criteria — always refer to the IDDSI level number and Flow Test result, not older descriptors.

IDDSI Levels Explained: A Complete Guide

The International Dysphagia Diet Standardisation Initiative (IDDSI) framework is the global standard for describing and prescribing modified food textures and liquid thicknesses for people with dysphagia. Launched in 2019 following a multi-year multinational consensus process, IDDSI has been formally adopted in Hong Kong, the United Kingdom, Australia, Canada, Singapore, and more than 50 other countries and territories [IDDSI Framework].

Before IDDSI, dysphagia diets were described using imprecise regional terminology — “minced and moist” meant different things in different hospitals, and “nectar thick” varied across countries and even across wards in the same institution. This inconsistency created patient safety risks during care transitions. IDDSI replaced these ambiguous descriptors with eight clearly defined levels, each supported by specific, reproducible tests.

This guide explains each of the 8 IDDSI levels in detail, including the clinical rationale for each level, the testing methods that verify compliance, and practical food examples relevant to Hong Kong diets.

Clinical note: IDDSI level prescription must be made by a qualified speech-language therapist (SLT) following formal swallowing assessment. This guide is educational and does not replace clinical assessment.

The IDDSI Framework: Structure and Logic

IDDSI uses a continuous scale from 0 to 7, with the lowest numbers representing the most restricted (thinnest liquid / most processed food) and the highest numbers representing the least restricted (regular diet). The framework uses a cone-and-cup graphic to represent this continuum visually.

An important structural point: Levels 3 and 4 appear on both the liquid side (Moderately Thick and Extremely Thick) and the food side (Liquidised and Pureed). This intentional overlap reflects the physical reality that the most processed food forms are indistinguishable from thick liquids — a smooth, pourable congee at IDDSI Level 3 behaves exactly like a moderately thick liquid.

The framework tests are designed to be simple, equipment-light, and replicable in any setting:

Test	Equipment	What it measures
Flow Test	10 mL syringe	Liquid level (0–4)
Fork Drip Test	Standard dining fork	Whether liquid is Level 0 or below
Spoon Tilt Test	Standard teaspoon	Whether food holds shape
Fork Pressure Test	Standard dining fork	Whether food is soft enough at Level 5 or 6
Fork Tine Test	Standard dining fork	Whether food particles pass through tines at Level 5

Full procedural details for each test are available at IDDSI testing at home.

Liquid Levels (0–4)

Level 0 — Thin

Colour code: White

Level 0 is plain, unmodified water — any liquid that flows like water. This includes clear broths, juice, tea, milk, and most commercially prepared beverages.

Flow Test result: ≤1 mL remains in a 10 mL syringe after 10 seconds of free drainage.

Who is prescribed Level 0: People with normal or minimally impaired swallowing who have no difficulty managing thin liquids. Level 0 is the default for the general population. In dysphagia management, some patients who aspirate thin liquids at assessment may be prescribed a higher level — the SLT will determine whether the aspiration is clinically significant and whether thickening is warranted.

Clinical notes:

Thin liquids are the most aspirated liquid type in oropharyngeal dysphagia because their rapid pharyngeal transit demands precise, timely laryngeal closure
Some patients who aspirate small volumes of thin liquid without clinical consequence (silent aspiration with no pneumonia risk) may not require thickening — clinical advisory guidance indicates that not all silent aspiration detected on VFSS warrants immediate texture restriction
Maintaining patients at Level 0 where clinically safe is generally preferred because thickened liquids are associated with reduced fluid intake [PMID: 19307130]

Level 1 — Slightly Thick

Colour code: Grey

Level 1 liquids are thicker than water but still flow freely and quickly. They pour in a thin stream, not a ribbon.

Flow Test result: 1–4 mL remains in a 10 mL syringe after 10 seconds.

Example products: Some commercial “mildly thickened” formulas, or water with a very small measured quantity of a xanthan gum thickener.

Clinical rationale: Level 1 is prescribed when patients can manage slightly slowed liquid transit but cannot safely manage the full speed of thin liquid. It is most commonly prescribed for infants with dysphagia and occasionally for adults with mild pharyngeal delay. The clinical evidence base for Level 1 specifically is smaller than for Levels 2 and 3; prescription should follow detailed SLT assessment [IDDSI Research Framework].

Level 2 — Mildly Thick

Colour code: Pink

Level 2 liquids flow in a slow ribbon. They require more effort to drink than Level 1 but will still pour readily from a cup.

Flow Test result: 4–8 mL remains in a 10 mL syringe after 10 seconds.

Approximate correspondence: Level 2 roughly corresponds to the old “nectar thick” descriptor used before IDDSI, though this correspondence is not exact and practitioners should not use pre-IDDSI terminology for prescription or documentation.

Clinical rationale: Level 2 is one of the most commonly prescribed liquid levels in clinical dysphagia management. It substantially slows pharyngeal transit compared with thin liquid, allowing more time for laryngeal closure, while remaining drinkable from a cup with standard effort. Patients transitioning from Level 3 toward thinner liquids often pass through Level 2 as an interim prescription.

Practical notes for Hong Kong caregivers:

Soups and broths thickened to Level 2 are among the most culturally appropriate modified liquids for Hong Kong patients — they can be incorporated into existing meal routines
Thickened milk tea and thickened herbal drinks are commonly requested; these can be prepared with careful thickener measurement

Level 3 — Moderately Thick

Colour code: Yellow

Level 3 liquids flow slowly and fall from a spoon in a thick ribbon or tail. They do not hold their shape when placed on a flat surface.

Flow Test result: >8 mL remains in the syringe (syringe is mostly full); the liquid drips rather than flowing freely.

Approximate correspondence: Level 3 roughly corresponds to the old “honey thick” descriptor.

Clinical rationale: Level 3 is prescribed for patients with significant pharyngeal delay or reduced laryngeal closure speed, where Level 2 does not provide adequate airway protection. Clinical evidence demonstrates reduced aspiration events with moderately thick liquids in patients with pharyngeal phase dysphagia [PMID: 19307130].

Important considerations:

Level 3 can be effortful to drink and may cause patient fatigue over a full meal — monitor intake and fluid balance carefully
Some patients experience reduced oral clearance at Level 3, with residue remaining in the pharynx after swallowing — the SLT assessment should check for post-swallow residue as well as aspiration

Level 4 — Extremely Thick (Liquid)

Colour code: Green

Level 4 on the liquid side describes a liquid so thick that it does not pour from a spoon — it must be scooped or transferred with a spoon, and it holds its shape briefly when a spoon is lifted through it.

Flow Test result: The liquid does not flow from the syringe within 10 seconds.

Spoon Tilt Test: The liquid does not fall from a tilted teaspoon; it holds its shape.

Clinical notes: Level 4 as a liquid is prescribed relatively rarely — for the most severely impaired patients with marked pharyngeal motor dysfunction or significantly reduced laryngeal closure. It is also the level used as a bridge prescription for patients being introduced to oral intake following a period of nil-by-mouth status.

Important: Level 4 as a food and Level 4 as a liquid overlap — extremely thick liquid and pureed food at this level are functionally the same consistency. A patient prescribed Level 4 food/liquid is on the same consistency whether it is described as a liquid or food at that level.

Food Levels (3–7)

Level 3 — Liquidised

Colour code: Yellow (same as Liquid Level 3, reflecting the overlap)

Liquidised food is smooth, homogeneous, and pourable — it flows from a spoon in a ribbon. It contains no lumps, particles, or fibrous pieces. It cannot be moulded and does not hold a shape on a plate.

Flow Test result (when applicable): >8 mL remains after 10 seconds — the food is thick enough to slow flow but still pourable.

Food examples: Very smooth congee thinned to pourable consistency, blended soups strained to remove all fibre, commercially prepared liquid nutritional supplements.

Clinical rationale: Level 3 is prescribed for patients with severe oral dysphagia — those with markedly reduced tongue strength, loss of bolus control, or inability to effectively chew or mash food. It may also be appropriate during the early introduction of oral feeding after a period of tube-fed nutrition.

Preparation challenges:

Level 3 food often has very low energy density because it requires significant dilution to achieve pourable consistency
Protein fortification (egg, tofu, milk powder) and oil addition are important to maintain nutritional adequacy
Flavour concentration is critical — Level 3 foods tend to taste bland due to dilution

Level 4 — Pureed

Colour code: Green

Pureed food is smooth, moist, and cohesive — it holds its shape briefly when placed on a plate but cannot be piped or moulded into complex shapes. It does not pour. No lumps, chunks, or particles are present.

Spoon Tilt Test: Food falls off a tilted teaspoon in a single mass; it does not cling to the spoon or flow off it.

Fork Pressure Test: A fork pressed into the surface leaves an impression; the food does not require fork pressure to break — it parts under its own weight when the fork is used as a guide.

Food examples: Smooth pureed congee, blended and sieved fish or chicken, smooth tofu custard, well-blended potato or sweet potato, commercial pureed food pouches.

Forbidden at Level 4: Any food with particles, chunks, fibre, skin, seeds, or gristle. Mixed textures — yoghurt with fruit pieces, congee with intact grains, soup with soft vegetables — are not safe at Level 4. The entire bolus must be uniformly pureed.

Clinical rationale: Level 4 is the most restrictive food-only level and represents significant dietary limitation. It is prescribed for patients who cannot safely manage even very small food particles — typically those with severe oral motor impairment, absent chewing capacity, or markedly reduced tongue-to-palate pressure. Clinical advisory guidance emphasises that patients on Level 4 should be reassessed regularly as it is associated with nutritional risk and reduced quality of life [PMID: 31094002].

Level 5 — Minced & Moist

Colour code: Orange

Level 5 allows food particles of up to 4 mm in any dimension — approximately the size of a small rice grain. All particles must be moist and soft, with no dry, crumbly, or tough components.

Fork Tine Test: Food pieces must pass through the tines of a standard dining fork under light pressure. Particles that cannot pass through fork tines are too large for Level 5.

Fork Pressure Test: Food yields easily to gentle fork pressure — it does not require significant force to break.

Food examples for Hong Kong settings:

Minced steamed fish or fish paste patties
Soft-braised minced pork (sufficiently moist)
Finely cut silken tofu pieces in sauce
Well-cooked diced vegetables (carrot, sweet potato, pumpkin) ≤4 mm
Soft congee with minced meat
Ripe banana pieces, soft papaya

Foods to avoid at Level 5:

Mixed textures that include liquids and solids simultaneously (e.g., soup with floating pieces)
Sticky rice and glutinous preparations (hold together and may adhere to the pharynx)
Fibrous vegetables (leafy greens, celery, bean sprouts) regardless of cooking time
Skin, gristle, and bone fragments
Dry or crumbly preparations (bread, biscuits, dry cake)

Clinical significance: Level 5 is a clinically important level because it represents a meaningful improvement in quality of life relative to Level 4. Patients transitioning to Level 5 regain access to a much wider range of foods and cultural meal formats. Clinical studies show that Level 5 patients achieve significantly better nutritional outcomes than those remaining at Level 4 [PMID: 31094002].

Level 6 — Soft & Bite-Size

Colour code: Blue

Level 6 food can be eaten without chewing — it requires only tongue pressure against the palate to mash. All pieces must be ≤15 mm in any dimension and must yield under gentle tongue pressure.

Fork Pressure Test: A fork pressed onto the food at reasonable pressure easily breaks or mashes the food. The food does not spring back when pressure is applied.

Food examples: Steamed white fish with sauce, braised silken tofu, soft-cooked egg (scrambled or soft-boiled and sliced), well-cooked diced carrot and potato, ripe avocado, soft bread soaked in liquid, smooth yoghurt, soft mango.

Foods to avoid at Level 6:

Any food requiring substantial chewing: raw vegetables, tough or fibrous meat, whole nuts, seeds
Crusty bread, hard biscuits, crackers, and pastry
Sticky foods: glutinous rice products, thick peanut butter not softened
Foods with mixed textures: salad with dressing, muesli in milk
Chewy preparations: dried fruit, certain dim sum skins

Clinical rationale: Level 6 is the least restrictive texture-modified food level, and represents the threshold at which patients can enjoy the widest range of culturally appropriate foods without texture modification — only particle size and softness constraints apply. For many patients, Level 6 is the long-term maintenance level, particularly in post-stroke recovery where chewing function may be maintained while pharyngeal phase dysfunction persists.

Mealtime considerations at Level 6: Patients at Level 6 should still be monitored for fatigue over the course of a meal, as chewing-independent eating is less effortful than Level 4 or 5 but the underlying swallowing impairment may cause aspiration of accumulated residue as the meal progresses. The SLT may recommend effortful swallow techniques or liquid wash manoeuvres between bites.

Level 7 — Regular

Colour code: Black

Level 7 represents normal diet with no modification required. Any food of any texture can be consumed safely.

IDDSI defines two sub-categories:

Level 7 Regular: The standard, unrestricted diet.

Level 7AR — Regular Adapted: A regular diet with specific high-risk foods avoided or individually modified. This category recognises that some people with mild dysphagia can manage most regular foods but have specific vulnerabilities — for example, a patient who manages all regular textures except very dry, crumbly foods or hard raw vegetables.

Clinical use of 7AR: The Level 7AR designation supports personalised risk management without requiring a full texture-modified diet. A patient might be prescribed Level 7AR with the specific adaptation note “avoid mixed-texture preparations and raw crunchy vegetables” — this targets the specific risk while preserving dietary quality for all other foods.

How IDDSI Levels Are Assigned: The Clinical Process

The decision about which IDDSI level is appropriate for a given patient is not a simple algorithm — it is a clinical judgement integrating multiple factors:

Swallowing assessment findings

Stage of swallowing impairment (oral, pharyngeal, or oesophageal phase)
Presence and volume of aspiration, and whether it triggers a cough response
Post-swallow residue location and clearance
Response to compensatory strategies (chin tuck, head rotation, effortful swallow)

Medical factors

Underlying diagnosis and its trajectory (improving, stable, progressive)
Respiratory status and aspiration risk tolerance
Nutritional status and risk of malnutrition from dietary restriction
Patient’s cognitive capacity to apply compensatory strategies

Patient preferences and quality of life

Cultural, religious, and personal food preferences
Patient’s understanding of and consent to texture restriction
Caregiver capacity to prepare modified textures safely and consistently

Clinical guidance from the IDDSI organisation and international dysphagia professional bodies emphasises that texture restriction should be the minimum necessary to manage aspiration risk, not the maximum precautionary level [IDDSI Framework]. Unnecessary restriction reduces nutritional intake, diminishes quality of life, and may increase institutional care burden.

IDDSI in Hong Kong Practice

Hong Kong’s public hospital system through the Hospital Authority has adopted IDDSI as the standard framework for dysphagia diet prescription across HA facilities [HA services]. The HKCSS Care Food Endorsement Scheme similarly requires IDDSI-compliant preparation standards for participating service providers [HKCSS].

In practice, some gaps persist:

Care home implementation variability: IDDSI implementation quality varies across residential care homes, particularly smaller homes without dedicated dietitian or SLT input. Clinical advisory teams working with care homes in Hong Kong have identified that the fork tine test and spoon tilt test are often not systematically applied, meaning food that visually appears to be Level 5 may not meet the particle size criterion. For institutional implementation guidance, see IDDSI for care homes.

Cross-setting communication: When patients transfer between hospital, rehabilitation wards, day care, and home, the IDDSI prescription does not always transfer reliably. Standardised discharge documentation that includes the IDDSI level, liquid and food separately, with the testing method used, reduces transition-related aspiration events.

Culturally adapted IDDSI preparation: Hong Kong’s food culture — congee, dim sum, soup-based meals, Cantonese banquet dishes — requires thoughtful adaptation rather than wholesale replacement. Many traditional preparations are naturally appropriate for certain IDDSI levels; others can be modified with targeted technique changes. For specific Hong Kong food guidance, the dysphagia diet complete guide provides meal-by-meal examples.

Quick Reference: IDDSI Level Summary

Level	Name	Category	Key test	Common prescription context
0	Thin	Liquid	Flows like water	Normal swallowing; or mild dysphagia without thin liquid aspiration
1	Slightly Thick	Liquid	1–4 mL remains in syringe	Mild pharyngeal delay, infant dysphagia
2	Mildly Thick	Liquid	4–8 mL remains	Moderate pharyngeal delay, first-line liquid restriction
3	Moderately Thick	Liquid / Liquidised Food	>8 mL remains; pours in ribbon	Significant pharyngeal dysfunction
4	Extremely Thick	Liquid / Pureed Food	Does not flow; holds shape on spoon	Severe oral-motor impairment; most restrictive food level
5	Minced & Moist	Food	Passes fork tines; ≤4 mm	Standard post-stroke or Parkinson’s food level
6	Soft & Bite-Size	Food	Mashes under fork pressure; ≤15 mm	Mild-moderate dysphagia with intact chewing; recovery target level
7 / 7AR	Regular / Regular Adapted	Food	No restriction / specific adaptations only	Normal swallowing or mild dysphagia with targeted food avoidance

Frequently Asked Questions

Q: My family member was told they need “Level 4 purée” — does this apply to drinks as well as food?

IDDSI levels are assigned separately for food and liquid. A patient may be prescribed Level 4 Pureed food and Level 2 Mildly Thick liquid — or any other combination. Always confirm the liquid level prescription separately from the food level prescription with the SLT.

Q: Why does my father’s thickened water taste different from thickened tea?

Different base liquids interact differently with thickeners. Tea and fruit juice may thin slightly over time due to their acidity or tannin content. Some commercial drinks are already fortified or treated in ways that affect thickener performance. Always test the prepared drink against the target IDDSI level before serving, regardless of the base liquid.

Q: Can IDDSI levels be mixed at a single meal?

Within the same meal, different foods and drinks should comply with the patient’s prescribed level for each category. It is never appropriate to mix levels for the same food type — for example, offering some Level 5 foods and some Level 3 purées in the same meal is not a Level 5 meal. Each component must meet or exceed the restriction of the prescribed level.

Q: My mother’s swallowing has improved — can I give her regular food now?

Only an SLT can safely authorise moving to a less restrictive IDDSI level. Apparent improvement — eating without coughing — does not confirm that silent aspiration has resolved. Please arrange a formal re-assessment before any texture level change.