If you’re a healthcare professional working in the field of dysphagia, you’re probably familiar with the term IDDSI. On the other hand, if you’re someone with swallowing difficulties and have been recommended thickeners by a healthcare provider, you may have noticed this term on the back of the product’s packaging. IDDSI stands for International Dysphagia Diet Standardisation Initiative. This concept was first implemented in 2013. A committee developed a global and unified terminology for modified-texture food and liquids for people with swallowing difficulties (dysphagia).
If you want to learn more about dysphagia, you can read our blog on the topic.
So what exactly is IDDSI?
By standardizing terminology globally, it becomes easier for healthcare professionals and patients to understand and follow the recommended food textures or liquid consistencies. This reduces the risk of misunderstandings and greatly improves adherence and safety during mealtimes and swallowing.
For example, a Level 6 – Soft & Bite-Sized texture may be beneficial for someone who has limited ability to chew large pieces of food safely but can still manage smaller pieces in the mouth.
On the other hand, someone who needs to thicken their beverages to Level 2 – Mildly Thick may do so to improve their quality of life. It can help reduce coughing when drinking and lower the risk of aspirating liquids into the airways.
How are these levels categorized?
Every level of food texture or liquid consistency is categorized according to its characteristics, appearance, fluidity, and other measurable properties.
To standardize and accurately classify these levels, different testing methods are used. The objective is to achieve a consistent texture or consistency every time.
For example, for a Level 1 – Slightly Thick consistency, a flow test using a 10 ml syringe is conducted. If 1–4 ml of liquid remains in the syringe after a 10-second flow, the consistency meets the criteria for this level.
Another example is the fork test used for Level 5 – Minced and Moist textures. When pressed with a fork, the food particles should mash easily with minimal pressure and fit between the prongs of the fork. The recommended size for food pieces is a maximum of 4 mm in width and 15 mm in length.
Several other testing methods are also used to accurately categorize each level.
The picture below shows all the different levels of food and drink according to the IDDSI terminology.
If you’re curious about the IDDSI framework, its testing methods, and the characteristics of each level, click here.
For additional information and resources on IDDSI, visit their website here.
Disclaimer: this blog provides general information and should not be used to diagnose or treat a person. The information listed above does not replace the professional advice of a healthcare provider. It is recommended to seek professional advice tailored to your needs.
Reference
“IDDSI International Dysphagia Diet Standardisation Initiative”. IDDSI.org, 2025.