Dysphagia, or difficulty swallowing, can significantly impact an individual's ability to eat and drink safely. To address this, healthcare professionals often recommend texture-modified diets and thickened liquids. This article provides a detailed overview of dysphagia diet levels, focusing on the International Dysphagia Diet Standardisation Initiative (IDDSI) framework and the National Dysphagia Diet (NDD), offering practical guidance for caregivers and individuals managing dysphagia.
The Importance of Dysphagia Diet Levels
When swallowing is impaired, food or liquid can enter the lungs instead of the esophagus, leading to aspiration. Aspiration can cause pneumonia and other medical problems. Dysphagia diets are designed to minimize this risk by modifying the texture of foods and the thickness of liquids, making them easier and safer to swallow. These modifications compensate for muscle weakness or discoordination that may be present in the mouth, pharynx, or esophagus.
The International Dysphagia Diet Standardisation Initiative (IDDSI) Framework
The IDDSI Framework is now the gold standard for determining diet textures for dysphagia. The IDDSI framework consists of a continuum of 8 levels (0 - 7), where drinks are measured from Levels 0 - 4, while foods are measured from Levels 3 - 7. The IDDSI Framework provides a common terminology to describe food textures and drink thickness. This framework aims to provide a universal language for describing food textures and liquid consistencies, ensuring consistency and safety across different healthcare settings and countries. It's crucial to avoid alterations to the IDDSI framework, as this may lead to confusion and errors in diet texture or drink selection for patients with dysphagia. Derivative works extending beyond language translation are not permitted.
IDDSI Testing Methods
IDDSI Testing Methods are intended to confirm the flow or textural characteristics of a particular product at the time of testing. Testing should be done on foods and drinks under the intended serving conditions (especially temperature).
IDDSI Levels Explained
The IDDSI framework categorizes food textures and drink thickness into eight levels, from 0-7. To determine where any particular food or drink fits in the framework, use the tests for each category.
Read also: Understanding Dysphagia Diets
Drinks (Levels 0-4)
- Level 0: Thin - This is regular water-like consistency.
- Level 1: Slightly Thick
- Level 2: Mildly Thick (Nectar-like) - Flows off a spoon, similar to nectar or thick juice.
- Level 3: Moderately Thick (Honey-like) - Can be sipped from a cup or eaten with a spoon but requires some effort.
- Level 4: Extremely Thick (Pudding-like) - Usually eaten with a spoon and cannot be poured.
Foods (Levels 3-7)
- Level 3: Liquidised: This level requires food to be liquidized, meaning it needs to have a uniform consistency with no lumps. It can be drunk from a cup or taken with a spoon.
- Level 4: Pureed - Very smooth texture with no lumps. It holds its shape on a spoon.
- Level 5: Minced & Moist - Soft and moist foods with small, easily manageable pieces. For adults, equal to or less than 4mm width and no more than 15mm in length.
- 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, draining excess. If texture cannot be finely minced it should be pureed.
- Fish: Finely mashed in mildly, moderately, or extremely thick smooth, sauce or gravy, draining excess (for adults equal to or less than 4mm width and no more than 15mm in length).
- Fruit: Serve finely minced or chopped or mashed. Drain excess juice. 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.
- Vegetables: Serve finely minced or chopped or mashed. Drain any 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).
- Level 6: Soft & Bite-Sized - Soft, tender, and moist foods that can be easily mashed with a fork and are appropriate bite-sized pieces.
- 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/ spoonpressure 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.
- Level 7: Regular - Normal, everyday foods of soft/tender textures that are developmentally and age 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 Smaller or greater than 8mm pieces (Pediatrics) Smaller or greater than 15 mm = 1.5 cm pieces (Adults)
- 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.
- 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 final cooked pieces are soft and tenderServe in mildly, moderately of extremely thick sauce AND drain excess liquid. No hard lumps
- Fruit: Soft enough to be cut 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.
Foods with changing textures
Food that starts as one texture (e.g. firm solid) and changes into another texture specifically when moisture (e.g. water or saliva) is applied, or when a change in temperature occurs (e.g. Ice chips Ice cream/Sherbet if assessed as suitable by a Dysphagia specialist Japanese Dysphagia Training Jelly sliced 1 mm x 15 mm Wafers (also includes Religious Communion wafer) Waffle cones used to hold ice cream Some biscuits/ cookies/ crackers Some potato crisps - only ones made or formed from mashed potato (e.g.
National Dysphagia Diet (NDD) Levels
The National Dysphagia Diet (NDD), published in 2002, developed universal terminology for texture-modified diets. While the IDDSI is now the more widely adopted standard, understanding the NDD can still be helpful. It consists of three levels for solids, along with guidelines for liquid consistencies.
NDD Solid Levels
- Level 1: Dysphagia Pureed - Foods are totally pureed to a pudding-like consistency. No coarse textures, raw fruits or vegetables, or nuts are allowed.
- Level 2: Dysphagia Mechanically Altered - Includes foods that are soft textured and moist, making them easy to swallow. Soft, well-cooked foods, well-moistened ground meats, moist and well-cooked potatoes, noodles, and dumplings are examples of foods that are the proper texture for this diet. All foods of a pureed consistency are allowed on this diet.
- Level 3: Dysphagia Advanced - Foods that are nearly normal textures are allowed on the dysphagia advanced diet, with the exception of crunchy, sticky, or very hard foods. The diet includes bite-sized foods that are moist. Foods that are allowed on dysphagia level 1 and level 2 diets also are allowed on the dysphagia advanced diet.
NDD Liquid Consistencies
The NDD also addresses liquids. They are evaluated separately from solid foods. The thickness levels of fluids for patients with dysphagia are established according to the guidelines of the National Dysphagia Diet (NDD) and International Dysphagia Diet Standardization Initiative (IDDSI). The nectar- (level 2), honey- (level 3), and pudding-like (level 4) fluids in NDD are consistent with the mildly (level 2), moderately (level 3), and extremely (level 4) thick fluids in IDDSI, respectively. For the NDD framework, thickened fluids are categorized into four “consistency” levels established by the NDD task force: thin (1∼50 mPa･s), nectar-like (51∼350 mPa･s), honey-like (351∼1,750 mPa･s), and pudding-like (>1,750 mPa･s). These NDD levels were classified by the apparent viscosity (ηa,50) of a thickened fluid at a shear rate of 50 s−1, which corresponds to the shear rate in oral cavities made during swallowing.
Practical Considerations for Dysphagia Diets
Implementation and Monitoring
- Swallowing Assessment: First, complete a swallowing assessment to determine your patient’s current, safe diet level. An NPO diet may be appropriate for patients who have no swallowing reflex or no UES opening. It’s not appropriate for all patients who aspirate. If the patient is having a hard time staying awake, halt trials until they are alert and oriented.
- Food and Liquid Trials: Attempt thinner consistencies if the patient demonstrates no or minimal signs of dysphagia. Attempt thicker consistencies if the patient demonstrates signs or symptoms of dysphagia-including aspiration-with the food or liquid being trialed. Introduce safe swallowing strategies if the patient demonstrates signs or symptoms of dysphagia during the food and liquid trials.
- Strategies and Exercises: See our Swallowing Strategies & Exercises article for more details.Next, complete a few more food and liquid trials while using the swallowing strategies. Observe whether the signs or symptoms of dysphagia improved.
- Progression: If the strategies consistently improve the signs or symptoms of dysphagia AND the patient safely consumes the food and liquid in 80-100% of trials: Your dysphagia goal will be to continue trials with a speech therapist using these strategies.The speech therapist may upgrade the patient to these textures once they demonstrate safe swallowing AND consistent use of strategies across three sessions.
- Further steps: If the patient continues to demonstrate the same signs or symptoms of dysphagia, then trial thicker liquids and/or softer foods. Introduce swallowing exercises in order to improve underlying weakness or discoordination. Recommend repeat MBSS and FEES as appropriate. Many patients who are NPO and/or are tube-fed can recover enough to resume a fully PO diet. Looking for more?
- Collaboration: Tell all health care providers and caregivers that you are on a dysphagia diet.
Food Preparation and Presentation
- Pureeing Techniques: When preparing pureed foods, ensure a smooth, pudding-like consistency without lumps. A food processor or blender can be used.
- Moistening Foods: Add sauces, gravies, or broths to mechanically altered diets to increase moisture and ease swallowing.
- Flavor and Seasoning: Unless you have another dietary restriction, you should receive food that is flavored and seasoned like the food on a regular consistency diet.
- Visual Appeal: You may find it easier to adjust to a new diet if your food smells and tastes appealing. Take time to season it. It also may help to prepare meals that are visually appealing.
Nutritional Considerations
- Variety: It is important to include a variety of foods from all different food groups when providing a pureed diet, including fruits, vegetables, grains, meats and meat substitutes, and dairy foods. It is important to include a variety of foods from all different food groups when providing a mechanically altered diet, including fruits, vegetables, grains, meats and meat substitutes, and dairy foods. It is important to include a variety of foods from all different food groups when providing a dysphagia advanced diet, including fruits, vegetables, grains, meats and meat substitutes, and dairy foods.
- Slurry: A slurry is a soft, moist mixture often used for people with swallowing problems. An example is a slice of bread or a pancake moistened with milk. The moisture of the liquid makes it easier for someone with swallowing problems to swallow soft bread products.
- Supplements: To make sure you get enough calories and protein, you may include liquid nutrition supplements, such as Ensure, Boost, or Carnation Instant Breakfast if they are thickened to the correct texture, if needed. “Plus” versions of these products provide the most calories and protein per serving.
Specific Food Recommendations and Restrictions
Level 1: Dysphagia Pureed
- Allowed:
- Pureed meats (pureed to pudding-like consistency)
- Smooth soufflés
- Soft, moist tofu
- Hummus
- Pureed bread mixes
- Pregelled slurried breads, pancakes, French toast, waffles, sweet rolls, etc
- Smooth cooked cereals, such as farina-type cereals with a pudding-like consistency
- Pureed fruit
- Well-mashed fresh bananas
- Pureed vegetables without lumps, pulp, or seeds
- Tomato sauce without seeds
- Mashed potatoes and pureed potatoes with gravy, butter, margarine, or sour cream
- Well-cooked pasta, noodles, or pureed rice (blended to a smooth consistency)
- Smooth pudding custards, yogurt, pureed desserts, and soufflés
- Any smooth, homogenous beverage without lumps, chunks, or pulp (may need to thicken to proper consistency)
- Avoid:
- Whole, ground, or chopped meats, fish, or poultry
- Legumes or lentils, unless pureed
- Cheese and cottage cheese, unless pureed
- Eggs that are not pureed
- Nut butters, unless pureed into other foods to correct consistency
- All other bread, rolls, crackers, biscuits, pancakes, French toast, muffins, etc
- Dry cereals and cooked cereals with lumps, seeds, or chunks
- Whole fruits (fresh, frozen, canned, or dried)
- All other vegetables that are not pureed
- All other potatoes, rice, and noodles
- Plain mashed potatoes
- All other desserts
- If patient is on thickened liquids, restrict ice cream, ices, milk shakes, frozen yogurt, gelatin, and other frozen desserts, because they are thin-liquid consistency at room temperature
Level 2: Dysphagia Mechanically Altered
- Allowed:
- Moistened ground or cooked meat, poultry, or fish (serve with sauces)
- Casseroles without rice
- Moist, well-cooked pasta
- Moist meat loaf or meatballs
- Poached, scrambled, or soft-cooked eggs
- Tofu
- Well-cooked and moist mashed legumes or beans
- Soft, well-moistened pancakes
- Pureed bread mixes or slurried breads
- Cooked cereals with little texture, including oatmeal
- Slightly moistened, dry cereals with little texture
- Soft and drained canned or cooked fruits without seeds or skin
- Ripe bananas
- All soft, well-cooked vegetables that are in small pieces and mashable with a fork
- Well-cooked and moistened boiled, baked, shredded, or mashed potatoes
- Well-cooked pasta noodles in sauce
- Puddings and custards
- Soft fruit pies (bottom crust only)
- Crisps and cobblers with soft topping and no seeds
- Most canned fruits
- Soft moist cakes with icing or slurried cakes
- All beverages with little texture or pulp
- Avoid:
- Dry meats, such as bacon, sausage, or hot dogs
- Dry casseroles or casseroles with rice or large chunks
- Cheese cubes and slices
- Peanut butter
- Hard-cooked or crisp fried eggs
- Sandwiches and pizza
- Slices of bread
- Toast
- Coarse cooked cereals
- Whole-grain or coarse dry cereals
- Fresh or frozen fruits
- Cooked fruit with skin or seeds
- Cooked corn and peas
- Brussels sprouts, broccoli, cabbage, asparagus, or other rubbery cooked vegetables
- Potato skins and chips
- Fried potatoes
- Rice
- Dry, coarse cakes and cookies
- Desserts with nuts, seeds, coconut, pineapple, or dried fruit
- Rice or bread pudding
Level 3: Dysphagia Advanced
- Allowed:
- Thin-sliced, tender, or ground meats or poultry, well-moistened
- Fish
- Eggs (any preparation acceptable)
- Yogurt (no nuts or coconut)
- Casseroles with small chunks of tender or ground meat
- Well-moistened breads, biscuits, muffins, pancakes, waffles, etc (add jelly, margarine, and other toppings to moisten well)
- All well-moistened cereals
- All canned and cooked fruits
- Soft, peeled, ripe fresh fruits, such as peaches, kiwi, mangos, cantaloupe, etc
- Soft berries with small seeds, such as strawberries
- All cooked, tender vegetables
- Shredded lettuce
- All, including rice and tender fried potatoes
- All desserts, except those on the avoid list
- Any beverage of recommended consistency
- Avoid:
- Tough or dry meats or poultry
- Dry fish or fish with bones
- Chunky peanut butter
- Yogurt with nuts or coconut
- Dry bread, toast, crackers, etc
- Tough, crusty breads, such as French bread
- Coarse or dry cereals
- Hard-to-chew fresh fruits, such as apples or pears
- Stringy, pulpy fruits, such as papaya, pineapple, or mango
- Fresh fruits with tough peels, such as grapes
- Prunes, apricots, and other dried fruits (unless cooked)
- All raw vegetables, except shredded lettuce
- Cooked corn
- Rubbery cooked vegetables
- Tough or crisp fried potatoes
- Dry cakes or cookies that are chewy
- Anything with nuts, seeds, dry fruits, coconut, and pineapple
Thickened Liquids: Achieving the Right Consistency
Thickening liquids is a common strategy to slow down the flow rate and allow more control during swallowing. Various commercial thickeners are available, typically using xanthan gum or starch as the active ingredient.
Considerations for Thickening Liquids
- Type of Liquid: Three commercially accessible cold drinks in Korea such as bottled water (Jeju Samdasoo), orange juice (The Coca-Cola Co.), and whole milk (Seoul Dairy Co.) were used as the dispersion medium to prepare thickened drinks. The concentration range of the thickener in thickened drinks at each IDDSI and NDD level increased in the following order: water> orange juice> milk. Composition is greatly influenced the results of the IDDSI flow test and NDD viscosity, showing that the ηa,50 and SFT values within each thickness level varied depending on the type of drink.
- Thickener Concentration: The thickener concentration ranges of thickened drinks for the classification of NDD levels differed from those of IDDSI levels, and they appeared to be greatly influenced by the type of drink. A small difference in the concentration of the thickener makes a significant difference in the ηa,50 and remaining volume (mL) of each thickened drink.
- Testing: The thickener concentration ranges for thickened drinks in each range of NDD and IDDSI levels increased in the following order: water> orange juice> milk. Specifically, the thickener concentration ranges for thickened water in NDD and IDDSI levels 2 and 3 were greatly wider than those of other thickened drinks, and the thickened water needed more amounts of thickener to reach NDD and IDDSI level 4.
- Temperature: The viscosity of thickened drinks was measured with a rheometer (RheoStress 1, Haake GmbH) through plate geometry. The sample was applied between parallel plates at 8°C. After a 5 min stabilization time at 8±0.1°C, the flow behaviors were measured over shear rate boundaries of 0.1∼100 s−1.
Read also: Safe Eating with Dysphagia
Read also: Understanding Dysphagia Diets