IDDSI For Beginners: The 9 Modified Diet Textures & Thickened Liquid Levels 

A common compensatory strategy for dysphagia is modifying diets and liquids, but what’s the best way to describe them?

The International Dysphagia Diet Standardisation Initiative (IDDSI) gives swallowing therapists around the world a common language to do just that.

In this article, you’ll learn about IDDSI’s modified textures and liquids levels, with examples.

Bookmark this page to quickly check when treating. And feel free to print the info to use with your speech therapy patients.

Visit the IDDSI website for their framework, supporting evidence, and how to measure and test foods/drinks.

IDDSI Disclaimer: These are NOT official IDDSI resources, educational materials or education programs and they are NOT meant to replace materials and resources on www.IDDSI.org.

What Does IDDSI Stand For?

IDDSI stands for the International Dysphagia Diet Standardisation Initiative (IDDSI). It offers a common language to describe food textures and drink thickness. 

The IDDSI framework was created for people with dysphagia and is a global standardization that applies to all languages, people, and settings (iddsi.org, 2019). 

IDDSI’s goal is to standardize how food and liquid textures are described to make eating and drinking safer for those with swallowing disorders. It aims to eliminate confusion between professionals, patients, and families when communicating.

IDDSI was updated in 2019 with new terminology for both modified textures and liquids. The following visual describes the newly updated IDDSI ‘foods’ and ‘drinks’ levels.

_{^{© The International Dysphagia Diet Standardisation Initiative 2019 @ https://iddsi.org/. Licensed under the CreativeCommons Attribution Sharealike 4.0 License https://creativecommons.org/licenses/by-sa/4.0/legalcode. Derivative works extending beyond language translation are NOT PERMITTED.}}

IDDSI Video

Here is a video overview of IDDSI and the modified textures and liquids.

What Are Thickened Liquids?

Thickening liquids is a compensatory strategy to improve symptoms of dysphagia in some patients by slowing the flow of the liquid bolus (ASHA, 2024).

A thickened liquid is any liquid that is naturally thicker or has been modified to be thicker than a thin liquid. Examples of thin liquids are water, milk, and coffee. 

Thin liquids can be thickened using starch-based powder or gum-based gel.

For more on thickening liquids, read Thickened Liquids for Dysphagia: What, When, Why, & How

IDDSI Levels for Liquids

_{^{© The International Dysphagia Diet Standardisation Initiative 2019 @ https://iddsi.org/. Licensed under the CreativeCommons Attribution Sharealike 4.0 License https://creativecommons.org/licenses/by-sa/4.0/legalcode. Derivative works extending beyond language translation are NOT PERMITTED.}}

• Thin – Level 0​
• Slightly thick – Level 1​
• Mildly thick – Level 2​
• Moderately thick – Level 3​
• Extremely thick – Level 4​

1. IDDSI Level 0 (Thin)

Most drinks are thin liquids, including water, coffee, low-fat milk, and soda.

IDDSI Description/Characteristics

• Flows like water
• Fast flow
• Can drink through any type of cup, straw, or teat/nipple as appropriate for age and skills

IDDSI Level 0 Examples

Most liquids, including water, coffee, milk, soda, and tea.

2. IDDSI Level 1 (Slightly Thick)

Also known as natural nectar thick.

IDDSI Description/Characteristics

• Thicker than water
• Requires a little more effort to drink than thin liquids
• Flows through a straw, syringe, teat/nipple

IDDSI Level 1 Examples

Some fruit nectars, apricot juice, tomato juice, some milk-based drinks (some melted ice creams, latte).

3. IDDSI Level 2 (Mildly Thick)

Also known as nectar thick. Similar in consistency to thick chocolate milk or creamy soup. These liquids flow quickly off of a spoon and take some effort to drink through a straw.

IDDSI Description/Characteristics

• Flows off a spoon
• Sippable, pours quickly from a spoon, but slower than thin drinks
• Mild effort is required to drink this thickness through standard bore straw (standard bore straw = 0.209 inch or 5.3 mm diameter)

IDDSI Level 2 Examples

Some smoothies and milkshakes.

4. IDDSI Level 3 (Moderately Thick)

Also known as honey thick. Similar to the consistency of honey. These liquids can be poured, but they move slowly when shaken.

IDDSI Description/Characteristics:

• Can be drunk from a cup
• Moderate effort is required to suck through a standard bore or wide bore straw (wide bore straw = 0.275 inch or 6.9 mm)
• Cannot be piped, layered, or molded on a plate because it will not retain its shape
• Cannot be eaten with a fork because it drips slowly in dollops through the prongs
• Can be eaten with a spoon
• No oral processing or chewing is required. Can be swallowed directly
• Smooth texture with no ‘bits’ (lumps, fibers, bits of shell or skin, husk, particles of gristle or bone)

IDDSI Level 3 Examples

Canned tomato soup, sauces, gravies, honey, and syrups.

You can liquify foods using a food processor or blender. Use liquids as needed to attain the right texture (broth to meats, milk to eggs, juice to vegetables, etc.).

5. IDDSI Level 4 (Extremely Thick)

Also known as a blended or pureed diet. Foods in a pureed diet are typically eaten with a spoon. Food should be smooth, moist with no lumps, and require no chewing.

IDDSI Description/Characteristics

• Usually eaten with a spoon (a fork is possible)
• Cannot be drunk from a cup because it does not flow easily
• Cannot be sucked through a straw
• Does not require chewing
• Can be piped, layered or molded because it retains its shape, but should not require chewing if presented in this form
• Shows some very slow movement under gravity but cannot be poured
• Falls off spoon in a single spoonful when tilted and continues to hold shape on a plate
• No lumps
• Not sticky
• Liquid must not separate from solid

IDDSI Level 4 Food Examples

Smooth mashed potatoes, pudding, frozen yogurt, milkshakes, thick cereal.

You can puree foods in a food processor. If needed, add liquids to attain a puree texture (broth to meats, milk to eggs, juice to vegetables, etc.).

Get patient dysphagia diet handouts in the Dysphagia Pack.

What Are Modified Diet Textures?

Modified diet textures are when foods are broken down to make chewing, bolus modification, and swallowing easier. Foods may be blended, minced, diced, chopped, and/or cut.

IDDSI Levels for Foods

IDDSI provides a detailed guide of modified textures and terminology recommended for use in all settings.

_{^{© The International Dysphagia Diet Standardisation Initiative 2019 @ https://iddsi.org/. Licensed under the CreativeCommons Attribution Sharealike 4.0 License https://creativecommons.org/licenses/by-sa/4.0/legalcode. Derivative works extending beyond language translation are NOT PERMITTED.}}

• Liquidised – Level 3
• Puree – Level 4
• Minced and Moist – Level 5
• Soft and Bite-sized – Level 6
• Easy to chew – Level 7
• Regular – Level 7

IDDSI Level 3 (Liquidised)

See above

IDDSI Level 4 (Puree)

See above.

6. IDDSI Level 5 (Minced and Moist)

Also known as a ground, dysphagia mechanical, or mechanically altered diet. Food should be soft and moist with no separate thin liquids. Foods can have lumps that are easily mashed using your tongue.

IDDSI Description/Characteristics

• Can be eaten with a fork or spoon
• Could be eaten with chopsticks in some cases, if the individual has very good hand control
• Can be scooped and shaped (e.g. into a ball shape) on a plate
• Soft and moist with no separate thin liquid
• Small lumps visible within the food
  • Adult, equal to or less than 4mm width and no longer than 15mm in length
• Lumps are easy to squash with tongue

IDDSI Level 5 Food Examples

• Meat
  • Finely minced or chopped (for adults, equal to or less than 4mm width and no more than 15mm in length)
  • Serve in mildly, moderately, or extremely thick smooth sauce or gravy AND drain excess liquid
  • If texture cannot be finely minced, it should be pureed
• Fish
  • Finely mashed in mildly, moderately, or extremely thick smooth sauce or gravy AND drain excess liquid
  • For adults equal to or less than 4mm width and no more than 15mm in length
• Fruit & Vegetables
  • Serve finely minced or chopped or mashed
  • Drain excess juice or liquid
  • If needed, serve in mildly, moderately, or extremely thick smooth sauce or gravy AND drain excess liquid
  • No thin liquid should separate from food
  • For adults, equal to or less than 4mm width and no more than 15mm in length
• Cereal
  • Thick and smooth with small soft lumps
  • Texture fully softened
  • Any milk/fluid must not separate away from cereal. Drain any excess fluid before serving.
  • For adults, equal to or less than 4mm width and no more than 15mm in length
• Bread
  • No regular, dry bread, sandwiches, or toast of any kind
  • Pre-gelled ‘soaked’ breads that are very moist and gelled through the entire thickness
• Rice, couscous, quinoa (and similar food textures)
  • Not sticky or glutinous
  • Should not be particulate or separate into individual grains when cooked and served
  • Serve with smooth mildly, moderately, or extremely thick sauce AND sauce must not separate away from rice, couscous, quinoa (and similar food textures). Drain excess fluid before serving.

7. IDDSI Level 6 (Soft and Bite-Sized)

Also known as a mechanical soft, diced, or chopped diet. Food should be soft, tender, moist, and bite-sized with no separate thin liquid. These foods need to be chewed before swallowing.

IDDSI Description/Characteristics

• Can be eaten with a fork, spoon, or chopsticks
• Can be mashed/broken down with pressure from fork, spoon, or chopsticks
• A knife is not required to cut this food, but may be used to help load a fork or spoon
• Soft, tender, and moist throughout but with no separate thin liquid
• Chewing is required before swallowing
• ‘Bite-sized’ pieces as appropriate for size and oral processing skills

IDDSI Level 6 Food Examples

• Meat
  • Cooked, tender meat no bigger than (for adults) 15 mm = 1.5 x 1.5 cm pieces
  • If texture cannot be served soft and tender at 1.5 cm x 1.5 cm (as confirmed with fork/spoon pressure test), serve minced and moist
• Fish
  • Soft enough cooked fish to break into small pieces with fork, spoon or chopsticks. No larger than 15 mm = 1.5 x 1.5 cm pieces (for adults)
  • No bones or tough skins
• Casserole/Stew/Curry
  • Liquid portion (e.g. sauce) must be thick (as per clinician recommendations)
  • Can contain meat, fish, or vegetables if final cooked pieces are soft and tender and no larger than 15 mm = 1.5 x 1.5 cm pieces for adults
  • No hard lumps
• Fruit
  • Serve minced or mashed if cannot be cut to soft & bite-sized pieces. 15 mm = 1.5 x 1.5 cm pieces (for adults)
  • Fibrous parts of fruit are not suitable
  • Drain excess juice
  • Assess individual ability to manage fruit with high water content (e.g. watermelon) where juice separates from solid in the mouth during chewing
• Vegetables
  • Steamed or boiled vegetables with final cooked size of 15 mm = 1.5 x 1.5 cm pieces (for adults)
  • Stir-fried vegetables may be too firm and are not soft or tender. Check softness with fork/spoon pressure test
• Cereal
  • Smooth with soft tender lumps no bigger than 15 mm = 1.5 x 1.5 cm pieces (for adults)
  • Texture fully softened
  • Any excess milk or liquid must be drained and/or thickened to thickness level recommended by clinician
• Bread
  • No regular dry bread, sandwiches, or toast of any kind
  • Pre-gelled ‘soaked’ breads that are very moist and gelled through the entire thickness
• Rice, couscous, quinoa (and similar food textures)
  • Not particulate/grainy, sticky or glutinous

8. IDDSI Level 7 (Easy To Chew)

Also known as dysphagia advanced, advanced soft, or dental diet. These are everyday soft or tender foods.

IDDSI Description/Characteristics

• Normal, everyday foods of soft/tender textures that are developmentally/age/patient-appropriate
• Any method may be used to eat these foods
• Sample size is not restricted at Level 7, therefore, foods may be of a range of sizes
• Does not include: hard, tough, chewy, fibrous, stringy, crunchy, or crumbly bits, pips, seeds, fibrous parts of fruit, husks or bones.
• May include ‘dual consistency’ or ‘mixed consistency’ foods and liquids if also safe for Level 0, and at clinician discretion. If unsafe for Level 0 Thin, liquid portion can be thickened to clinician’s recommended thickness level.

IDDSI Level 7 Food Examples (Easy To Chew)

• Meat
  • Cooked until tender.
  • If texture cannot be served soft and tender, serve minced and moist
• Fish
  • Soft enough cooked fish to break into small pieces with the side fork, spoon or chopsticks
• Casserole/Stew/Curry
  • Can contain meat, fish, vegetables, or combinations of these if the final cooked pieces are soft and tender
  • Serve in mildly, moderately, or extremely thick sauce AND drain excess liquid
  • No hard lumps
• Fruit
  • Soft enough to be cut and broken apart into smaller pieces with the side of a fork or spoon. Do not use the fibrous parts of fruit (e.g. the white part of an orange).
• Vegetables
  • Steam or boil vegetables until tender. Stir-fried vegetables may be too firm for this level. Check softness with fork/spoon pressure test
• Cereal
  • Served with texture softened
  • Drain excess milk or liquid and/or thicken to thickness level recommended by clinician
• Bread
  • Bread, sandwiches, and toast that can be cut or broken apart into smaller pieces with the side of a fork or spoon can be provided at clinician discretion
• Rice, couscous, quinoa (and similar food textures)

Get patient dysphagia diet handouts in the Dysphagia Pack.

9. IDDSI Level 7 (Regular Textures)

Every food that the patient eats.

IDDSI Description/Characteristics

• Normal, everyday foods of various textures that are developmental/age/pateint-appropriate
• Any method may be used to eat these foods
• Foods may be hard and crunchy or naturally soft
• Sample size is not restricted at Level 7; therefore, foods may be of a range of sizes
• Includes hard, tough, chewy, fibrous, stringy, dry, crispy, crunchy, or crumbly bits
• Includes food that contains pips, seeds, pith inside skin, husks, or bones
• Includes ‘dual consistency’ or ‘mixed consistency’ foods and liquids

IDDSI Level 7 Food Examples (Regular Textures)

All the foods!

When Should You Use The IDDSI?

We recommend using the updated IDDSI vocabulary when discussing, recommending, and ordering dysphagia diets and/or liquid consistencies.

This will help keep communication terms consistent and leave less room for confusion!

If your medical facility uses outdated IDDSI terminology (pre-2019 update), here are ideas for making the shift:

• Collaborate with your facility’s dietitian to develop a plan for training kitchen and nursing staff (Wu et al, 2022)
• Provide in-services, handouts, and food/liquid preparation demonstrations to better explain and show IDDSI levels. 
• Work with your company’s IT department to implement the new IDDSI terminology into your EMR system, if possible.

More Dysphagia Resources

See The Dysphagia Workbook for ready-made patient handouts and treatment guides (included in The Adult Speech Therapy Starter Pack).

For a step-by-step guide to dysphasia assessment, treatment, and documentation, check out The Adult Speech Therapy Roadmap!

References

• American Speech-Language-Hearing Association. (n.d.). Adult Dysphagia. (Practice Portal). Retrieved Nov, 1, 2024, from www.asha.org/Practice-Portal/Clinical-Topics/Adult-Dysphagia/.
• Brewer, C., Aparo, M. (2021) The Adult Speech Therapy Starter Pack. Harmony Road Design Publishing.
• IDDSI. (n.d.). International Diet Standardisation Initiative. Retrieved Nov 3, 2024 from https://www.iddsi.org/home 
• Wu, X. S., Miles, A., & Braakhuis, A. (2022). The Effectiveness of International Dysphagia Diet Standardization Initiative-Tailored Interventions on Staff Knowledge and Texture-Modified Diet Compliance in Aged Care Facilities: A Pre-Post Study. Current developments in nutrition, 6(4), nzac032. https://doi.org/10.1093/cdn/nzac032