What Is a Clear Liquid Diet?

In This Article

A clear liquid diet is a type of mechanically altered diet that includes only liquids without any pulp, bits of food, or other residues. It's usually prescribed for a short time before a medical test, procedure, or surgery, or if you need to give your gastrointestinal system a rest. A clear liquid diet keeps you hydrated, but it doesn't provide any solids that have to be digested or pass through your intestinal tract.

Benefits

A clear liquid diet is easy to digest, reduces strain on your digestive tract, and doesn't contribute any residue to your colon. Although it's very low in calories and most nutrients, it can still provide some glucose and electrolytes, so it will keep you hydrated and provide a small amount of nutrition for the time you're required to follow it.

This type of diet may be recommended for a number of reasons, most notably as part of your bowel prep for a colonoscopy or in preparation for surgery or a procedure like an endoscopy.

A clear liquid diet is also used within two hours prior to and immediately following bariatric surgery, per recommendations from the Enhanced Recovery After Surgery (ERAS) Society (start a clear liquid diet within a few hours after surgery and work with a dietitian to advance the diet as you're ready).

It's also used to give the stomach and intestines the chance to rest and heal from an illness or health condition that affects your gastrointestinal tract. If you have a stomach bug, following a clear liquid diet can help prevent dehydration and minimize any vomiting or diarrhea.

In the case of diverticulitis, a small percentage of people have had serious complications from eating solid foods. Therefore, recommendations published in the Annals of Internal Medicine state that you should stick to a clear liquid diet for several days as symptoms improve before advancing to a low-fiber diet.

If you have an inflammatory bowel disease like Crohn's disease or ulcerative colitis, you may benefit from a clear liquid diet for a short time if you have a serious flare-up with severe diarrhea. However, guidelines published in Clinical Nutrition recommend using a more complete liquid nutrition supplement or a low-residue (low-fiber) diet whenever possible because of the high risk of malnutrition associated with inflammatory bowel disease.

How It Works

A clear liquid diet consists of any fluids that are see-through and free from any solids or pulp. In addition, foods that melt into clear liquids at room temperature, like ice pops or gelatin, are also allowed. Liquids that are opaque are not allowed because these require more work to digest, and they'll leave a residue in your large intestine.

There is usually no restriction on the number of clear liquids you can consume in a day unless there is a concern about your stomach emptying properly or in time for a procedure. At a minimum, you should try to drink 8 ounces every hour or two to stay hydrated.

Duration

A clear liquid diet is very low in calories, protein, fat, and most nutrients, so it's meant to be used for only a few days at most. The National Institutes of Health recommends using a clear liquid diet for no more than three or four days, unless your healthcare provider advises you otherwise.

What to Eat

Compliant Foods

  • Fruit juices (e.g., apple, grape, or cranberry)

  • Clear beverages (e.g., lemon/lime soda, ginger-ale, seltzer water, lemonade)

  • Sports drinks

  • Plain teas or black coffee

  • Gelatin (plain, without fruit or whipped cream)

  • Ice pops or fruit-flavored ice (without solid fruit)

  • Clear broth or bouillon


  • Clear nutrition supplements (e.g., Boost Breeze, Pedialyte, Ensure Clear)

  • Clear candies (e.g., lollipops, gummies)

Non-Compliant Foods

  • Fruit juices with pulp (e.g., orange juice, grapefruit juice)

  • Nectars

  • Tomato or vegetable juices

  • Milk or non-dairy milks

  • Ice cream, sherbet, or any other desserts

  • Cream soups or those with vegetables, noodles, or rice

  • Alcoholic beverages

  • Nutrition supplements that are not clear (e.g., Ensure, Carnation Instant Breakfast)

  • Chocolates or other opaque candies

The clear liquid diet is very limited in its food choices. Try to have three or four choices from the Compliant Foods list for each meal.

Juices, soft drinks, sports drinks, gelatin, and ice pops: In some instances, such as for colonoscopy prep, you may be advised to avoid any red, purple, or blue foods or beverages. That means that white cranberry or grape juice is OK, but red cranberry or purple grape juice is not. Some flavors of gelatin, ice pops, and many nutrition supplements also have red, purple, or blue dye, which can be mistaken for blood on a colonoscopy, so avoid those or choose flavors that aren't red, purple, or blue.

You may choose some sugar-free versions of any of these foods or beverages, but most should have sugar unless you have diabetes and have been told to restrict how much you consume. Keep in mind, the added sugar will provide you with some calories or carbs, which can help to maintain your energy and blood sugar.

Coffee and tea: You can add sugar, honey, or lemon, but no milk, cream, or non-dairy creamer.

Nutrition supplements: Clear supplements can be helpful if you'll need to follow the clear liquid diet for more than a day or two because they provide additional calories, some protein, and some vitamins and minerals. Milk or soy-based supplements provide more nutrition, but they should be avoided.

Broth or bouillon: If you're on a sodium-restricted diet, ask if you should choose reduced-sodium or unsalted broth or bouillon. Also, be aware that some brands of chicken stock, beef stock, or bone broth have small amounts of solids and/or fat, so avoid these and stick to bouillon cubes or strained, clear broth.

Recommended Timing

You should try to eat or drink on somewhat of a regular schedule to stay hydrated and as full as possible. Clear liquids are digested very quickly, so they aren't as satisfying as a full meal. Aim to eat or drink about six times each day.

If you're scheduled for a procedure or surgery, make sure you follow your medical provider's instructions about when to stop the clear liquid diet. It's usually recommended that you have nothing by mouth within two hours of your procedure to reduce the risk of aspiration.

Considerations for General Nutrition

The clear liquid diet does not adhere to the 2015-2020 Dietary Guidelines from the U.S. Department of Health and Human Services and the U.S. Department of Agriculture; it will not meet your nutritional needs. You should advance your diet to full liquids, a puréed or soft diet, or a regular diet as soon as you're cleared to do so.

If you need to follow the diet for more than a few days, your doctor may recommend adding additional supplements or high-protein gelatin to boost your caloric and nutrient intake.

Side Effects

Although the clear liquid diet can take the strain off of your gastrointestinal tract, it may leave you feeling a bit weak and dizzy if you try to do too much. Take it slow while you're on the diet and avoid any extreme activity. You should be able to resume your normal routine once you're back to eating regular meals.

Dietary Restrictions

Although it's low in calories, a clear liquid diet can be high in carbs if you rely on sodas, juices, and other sugar-sweetened foods and beverages. It can also be high in sodium if you're eating broth multiple times each day. These may be concerns if you're on a low-sugar or low-salt diet, so you might need to choose modified products.

If you have diabetes, it's important to check with your clinician to see if you should use sugar-free clear liquids. If you take insulin or glucose-lowering medications, you may need to have your dose adjusted on this diet. It's also a good idea to check your blood sugar more frequently to avoid any risk of hyper or hypoglycemia.

A clear liquid diet can be a choking hazard if you have dysphagia or a problem swallowing thin liquids. Ask your healthcare provider or dietitian for an approved thickener to thicken your liquids to the right consistency.

Clear Liquid Diet vs. Full Liquid Diet

If you need to remain on a liquid diet for a longer duration, but a clear liquid diet is no longer necessary, your doctor may advance you to a full liquid diet. Full liquids are those that you can't see through, like milk, nectars, cream soups, and melted ice cream and sherbet. Full liquids require a bit more work to digest and they do contribute some residue to your colon.

A full liquid diet is still low in calories and nutrients, but not as low as a clear liquid diet. It also provides more variety and is higher in protein. It's considered a bridge between a liquid and a soft or puréed foods diet.

Do not change to a full liquid diet without your doctor's OK.

A Word From Verywell

It's important to note that a clear liquid diet is not meant to be followed for more than a few days and is only advised under the guidance of your healthcare provider. It is not meant to be used as a "detox" or weight loss diet.

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Thorell, A, MacCormick, AD, Awad, S, et al. Guidelines for perioperative care in bariatric surgery: Enhanced Recovery After Surgery (ERAS) society recommendations. World J Surg. 2016;40:2065. doi:10.1007/s00268-016-3492-3

  2. Oates JR, Sharma S. Clear liquid diet. Treasure Island, FL: StatPearls Publishing. Updated March 18, 2019.

  3. Swanson SM, Strate LL. Acute colonic diverticulitis. Ann Intern Med. 2018;168(9):ITC65-ITC80. doi:10.7326/AITC201805010

  4. Forbes A, Escher J, Hebuterne X, et al. ESPEN guideline: Clinical nutrition in inflammatory bowel disease. Clinical Nutrition. 2017;36(2):321-47. doi:10.1016/j.clnu.2016.12.027

  5. MedlinePlus. Clear liquid diet. Updated July 14, 2018.

  6. U.S. Department of Health and Human Services, U.S. Department of Agriculture. 2015–2020 Dietary guidelines for Americans. Eighth edition.