What does level 2 fluid mean? A nutrition diet guide

October 19, 2025 •

3 min read

According to the International Dysphagia Diet Standardisation Initiative (IDDSI) framework, level 2 fluid is formally known as 'mildly thick' and is designed for individuals who have difficulty safely swallowing thin liquids like water. This modification is a critical component of a nutrition diet for those with dysphagia, a condition affecting millions worldwide. By understanding what does level 2 fluid mean, caregivers and patients can ensure proper hydration and nutrition while minimizing the risk of aspiration.

Quick Summary

Level 2 fluid, or mildly thick liquid, is a modified beverage consistency used to improve swallowing safety for individuals with dysphagia. It is thicker than water but can still be sipped from a cup and requires moderate effort to drink through a straw. This consistency is achieved by adding a thickening agent to liquids. It is part of the IDDSI framework and is recommended by a speech and language therapist to reduce the risk of fluids entering the airway, which could lead to health complications like aspiration pneumonia.

Key Points

Mildly Thick Consistency: Level 2 fluid, according to the IDDSI framework, is a mildly thick liquid designed for individuals with swallowing difficulties.
Improved Swallowing Safety: The purpose of level 2 fluid is to slow the movement of liquids, giving individuals more time to manage their swallow and reducing the risk of aspiration pneumonia.
Requires Professional Recommendation: A speech and language therapist assesses a patient's swallowing ability and prescribes the specific fluid level, such as level 2.
Achieved with Thickeners: Level 2 fluids are typically made by adding a prescribed thickening powder or gel to thin liquids like water, juice, or coffee.
Includes Natural Options: Some naturally occurring liquids, like certain juices and milkshakes, may already fall within the mildly thick range and can be incorporated into the diet.
Maintains Nutrition and Hydration: A balanced nutrition diet with level 2 fluids helps ensure proper hydration and nutritional intake for individuals who struggle with thin liquids.
Requires Careful Preparation: To ensure safety, caregivers must follow precise instructions for mixing thickeners and test the consistency to avoid drinks that are too thin or too thick.

Understanding the IDDSI Framework

The International Dysphagia Diet Standardisation Initiative (IDDSI) established a global framework for classifying food textures and fluid thickness for individuals with swallowing problems. The framework uses a scale from 0 to 7, with level 2 specifically designating mildly thick liquids. This standardisation promotes clear communication among healthcare professionals and caregivers.

Characteristics of Level 2 (Mildly Thick) Fluids

Mildly thick liquids possess distinct properties:

They pour noticeably slower than thin liquids but still quickly from a spoon.
They can be sipped from a cup.
They offer slight resistance when stirred.
They can be consumed with some effort using a regular straw, though an SLT should confirm safety.
The IDDSI Flow Test helps confirm the consistency: 4-8 mL of fluid remains in a 10 mL syringe after 10 seconds.

Why Are Level 2 Fluids Prescribed?

Dysphagia can cause thin liquids to move too rapidly, increasing the risk of aspiration into the airway and potentially leading to pneumonia. A speech and language therapist may recommend level 2 fluids to slow the liquid flow, allowing better swallowing control.

Conditions That May Require a Level 2 Fluid Diet

Dysphagia can be caused by various conditions, including stroke, dementia, Parkinson's disease, head and neck cancers, brain injury, and motor neurone disease.

Creating a Balanced Nutrition Diet with Level 2 Fluids

Ensuring adequate hydration and nutrition is crucial for individuals on a thickened fluid diet, as the thicker consistency can sometimes reduce fluid intake. A registered dietitian can assist in developing a balanced nutrition plan.

Examples of Level 2 Fluid Sources

Safe options for level 2 fluids include any thin liquid thickened with a prescribed agent, some naturally thicker drinks like certain smoothies or juices (e.g., tomato, apricot, mango), fortified beverages, and moist, thickened pureed foods like custard. Note that foods that melt into thin liquids, like ice cream, are not suitable.

Preparing Level 2 Fluids

Commercial thickeners are the most reliable way to achieve the correct level 2 consistency. Xanthan gum-based thickeners are often preferred due to their stability.

Best Practices for Preparation:

Measure the thickener precisely according to the product instructions.
Mix the thickener thoroughly with the liquid, using a shaker or blender for milky drinks or larger quantities to avoid lumps.
Allow the mixture to stand for the recommended time to reach its final consistency.
If uncertain, use the IDDSI Flow Test to verify the consistency.

Level 2 Fluid vs. Other Consistencies

Understanding the differences between IDDSI fluid levels is essential for safety. Below is a comparison of characteristics for common fluid consistencies.


Feature	Level 0: Thin	Level 1: Slightly Thick	Level 2: Mildly Thick	Level 3: Moderately Thick
Flow Rate	Flows like water.	Flows a little less quickly than water.	Pours quickly from a spoon, but slower than thin liquids.	Pours very slowly like honey.
Appearance	Regular liquids like water, tea, coffee.	A slightly thickened appearance, similar to some fruit nectars.	A consistency like a thicker cream soup or pouring cream.	A thick, honey-like consistency.
Syringe Flow Test	Flows completely through a 10mL syringe in 10 seconds.	Not applicable	4-8mL remains in the 10mL syringe after 10 seconds.	8-10mL remains in the 10mL syringe after 10 seconds.
Can be Sipped?	Yes, but requires quick control.	Yes, with little effort.	Yes, can be sipped from a cup.	Can be sipped, but often more easily managed with a spoon.
Straw Use	Yes, with ease.	Yes, with little effort.	Yes, but with some effort.	Difficult or impossible for most.

Conclusion

Level 2 fluid, or mildly thick liquid, is a key component of a nutrition diet for individuals with dysphagia. Prescribed by an SLT, its thicker consistency helps improve swallowing safety by slowing liquid flow and reducing aspiration risk. A balanced diet of level 2 fluids, achieved through proper preparation with thickeners and incorporating naturally thicker options, is essential for hydration and nutrition. Monitoring by healthcare professionals is vital for maintaining the well-being of those with swallowing difficulties.

For more detailed information on the IDDSI framework and testing methods, a valuable resource is the International Dysphagia Diet Standardisation Initiative (IDDSI).

Frequently Asked Questions

IDDSI level 2 refers to 'mildly thick' fluids within the International Dysphagia Diet Standardisation Initiative framework. This consistency is thicker than water but can still be sipped from a cup and pours relatively quickly from a spoon.

Individuals with dysphagia, or swallowing difficulties, may be prescribed level 2 fluids by a speech and language therapist. This is often recommended when thin liquids are swallowed too quickly, leading to a risk of aspiration.

To prepare level 2 fluids, you add a prescribed amount of thickening powder or gel to a liquid, following the product's specific instructions. Ensure thorough mixing and allow the mixture to stand for the recommended time to achieve the correct consistency.

Examples of level 2 liquids include water or juice thickened with powder, some smoothies and milkshakes, and certain fruit nectars like apricot or mango juice.

Consuming level 2 fluids with a straw may require some effort. An individual should only use a straw if explicitly approved by their speech and language therapist, as it can sometimes make swallowing more difficult.

While some household products like cornflour can thicken liquids, they are not recommended for consistently creating safe, stable, and accurate consistencies. Prescribed, commercially available thickeners are resistant to saliva enzymes and designed for specific dysphagia needs.

Incorrectly prepared thickened fluids can increase the risk of choking and aspiration. If too thin, the fluid is difficult to control. If too thick, it can leave residue in the throat that can be aspirated later.