The Full Liquid Diet

If you are starting a full liquid diet, you can expect to consume only liquids or foods that turn liquid at room or body temperature. There are several reasons why your doctor may recommend a liquid diet—for example, if you are having digestive problems or are preparing for a colonoscopy.

This article discusses the risks and benefits of liquid-only diets and reasons why doctors sometimes prescribe them. It also includes a list of foods you can and cannot have as part of a full liquid diet.

Benefits

Your doctor may prescribe a liquid-only diet if you are having trouble swallowing (dysphagia) or chewing solid food. You may also need to start this diet if you are at risk of choking or inhaling food particles into your airways (aspiration) when you eat.

Your doctor may prescribe a full liquid diet if you have missing teeth, open wounds, or stitches in your mouth. Sticking to a liquid diet until these have closed will allow your mouth to heal and prevent food bits from getting stuck in openings and causing infection.

On top of that, not having to chew chunks of food can help reduce pain after a recent dental procedure or jaw injury.

If your digestive system is slow or damaged from illness, disease, or surgery, being on a liquid diet while you heal can help manage pain and prevent complications, like a blockage in your intestines (bowel obstruction).

If you're preparing to have a test or imaging procedure to see inside your stomach and intestines, you may need to be on a liquid diet for a day or two beforehand. This will ensure that no undigested food is left in your gastrointestinal (GI) tract, which could affect the results.  

You may also need to be on a liquid diet to prepare for medical procedures that require you to be under general anesthesia. Having only clear liquids before surgery lowers the risk of choking or vomiting up undigested stomach contents when your muscles are paralyzed by anesthesia.

Clear liquids, like water and apple juice, leave the stomach quickly—within 10 to 20 minutes after they are consumed. Solid foods typically take between 24 to 72 hours to digest.

full-liquid-diet

Verywell / Joshua Seong

How It Works

The full liquid diet allows you to have clear fluids as well as thicker ones, like milk, fruit juice, shakes, and smoothies. Your doctor may also give you permission to have other foods, like yogurt or puréed fruits, so long as there are no lumps or solid pieces.

These will be your only options while on a full liquid diet, which can make it hard to get enough nutrients and calories each day. You will need to follow your doctor's instructions closely to make sure you are still getting all the nutrients your body needs.

A registered dietitian or nutritionist can be a helpful resource, especially if you have additional food allergies or dietary restrictions.

Duration

The full liquid diet is generally prescribed for only a few days to help you transition back to your normal diet. It’s rarely used for longer than two weeks.

Exceptions may be made for people who are preparing for bariatric (weight loss) surgery, recovering from a fractured jaw, or who use the diet to manage flare-ups of certain health conditions, like Crohn's disease.

Due to its restrictive nature, you should be closely monitored by your doctor when on a full liquid diet for more than a few days.

What to Eat

You’ll have your choice of beverages on a full liquid diet. With the right tools, you can also make many solid foods diet-friendly. Melting, thinning, straining, or puréeing fruits, vegetables, cheese, and even meat can help you stay nourished and satisfied.  

The following compliant foods are allowed in a full liquid diet. Non-compliant foods are not allowed because they are solid or their textures are too thick and lumpy.

Compliant Foods
  • Fruit and vegetable juice (no pulp)

  • Broth

  • Soft drinks

  • Sports drinks, electrolyte-replacement drinks

  • Coffee, tea

  • Milk or dairy-free milk alternatives (soy, almond)

  • Milkshakes, malts, smoothies

  • Clear or creamed soups (thinned, strained, no solids)

  • Honey, syrup, sugar

  • Gelatin, pudding, custard

  • Ice pops, ice cream, frozen yogurt, sorbet (no nuts, candy, solid toppings/coatings)

  • Yogurt (regular or Greek; no granola, seeds, fruit chunks)

  • Melted cheese

  • Powdered protein, dry milk, other nutritional supplements

  • Liquid dietary supplements (Ensure, Glucerna, Boost)

Non-Compliant Foods
  • Meat (unless puréed, thinned, and strained)

  • Tofu, meat substitutes

  • Nuts and seeds

  • Raw fruits and vegetables

  • Solid cheese

  • Soft or mashed food (e.g., potatoes)

  • Soups or stews with noodles, meat, or vegetables

  • Bread

  • Whole pasta or rice

  • Cereals, granola, oats

  • Applesauce

  • Potato chips, crackers, pretzels, popcorn

  • Muffins, cakes, cookies, pastries

  • Hard or chewy candy 

  • All other solid foods unless specifically approved by your healthcare provider

Juices: Fruit and vegetable juice is allowed on a full liquid diet as long as it has been strained to remove any solids (like pulp). You may need to avoid any high-fiber juice such as prune juice altogether. Making your own juice with a high-speed blender or juicer allows you to control the thickness. Or, pour the juice through a mesh sieve or tea strainer to remove residue.

Vegetables: Mashed potatoes and other types of vegetable mash are generally not approved but can be if they are sufficiently thinned. You can blend them with butter, gravy, or sauces, season to taste, and thin with water or broth. They should be no thicker than a smoothie when you're done.

Grains: Cooked cereals can be thinned with water or milk, then strained. Farina and rice cereal are also easy to thin this way. If you’re trying to add nutrition, prepare your cereal with whole milk or creamer instead of water or skim milk. 

Milk: Milk or lactose-free alternatives are approved. Drink your favorite by the glass and/or add it to smoothies and shakes for extra nutrition. Powdered milk can be added to cereals, soups, and eggs to boost protein.

Yogurt and cottage cheese: Regular yogurt works well as a base for sweeter-tasting liquid meals, and Greek yogurt can be a good base for more savory recipes. Cottage cheese is easy to blend into a liquid meal and most shredded cheese will melt easily with a little heat.

Butter: While you’re limited to a full liquid diet, use butter or margarine as often as you can to add calories and fat to your meals. 

Protein: Meat is approved as long as it’s the consistency of baby food. Mix meat with potato flakes and milk before or after cooking to give it the right consistency for a liquid diet.

Nut butter: Nut butter is a good source of healthy fats and protein that can be easily added to shakes or smoothies.

Eggs: Eggs, egg whites, or egg substitutes can be prepared soft and blended into a liquid meal. 

Dessert: Ice cream, frozen yogurt, and ice pops that melt at room temperature are approved on a liquid diet as long as they do not contain nuts, candy, or other hard pieces. Gelatin cups are allowed as-is. Puddings and custards can be thinned to a liquid consistency with milk. If you need to add calories, try topping ice cream, pudding, malts, or milkshakes with fruit that is thoroughly blended with whipped cream. 

Beverages: Any clear broths, pulp-free juices, or other drinks are approved on a full liquid diet. You can use milk, half-and-half, and non-dairy creamer to add calories to coffee or tea. Other hot beverages like cider, chai, and milk-based espresso drinks are also approved as long as they do not contain solid pieces such as chocolate flakes or mulling spices.

To ensure you’re properly nourished and hydrated, aim to drink at least 64 fluid ounces by the end of each day.

Recommended Timing

One challenge of a liquid diet is knowing whether you’ve consumed enough nutrition on a given day. As a general rule, have enough to feel satisfied.

That said, if you have certain digestive disorders or are recovering from illness or surgery, it's not uncommon to feel full quickly. The discomfort may set in before you've taken in enough calories to be fully nourished. 

Start by drinking as much as you comfortably can every 15 minutes. Try taking sips from a small glass rather than trying to drink larger amounts in one sitting. You may need to plan your liquid meals as often as six to eight times a day.

Cooking Tips

The easiest way to thin soft food to make it suitable for a full liquid diet is to add water. If food doesn't become a liquid at room or body temperature, as ice pops would, apply a little extra heat.

Dairy products like shredded cheese can be melted in the microwave and added to soups or purées. Chocolate can be melted in a saucepan on the stovetop. 

Kitchen tools like food processors can be a big help if you’ll be making liquid meals for yourself at home. A blender is useful as you purée fruits and veggies. You can also use it on a lower setting to easily “pulse” thicker foods like oatmeal into a safe consistency. 

Pasta, rice, and potatoes can be cooked until they are very soft, then thinned with water, butter, or gravy. You can also use water or milk and heat to soften crackers, which can then be added to soup or broth. 

Modifications 

Depending on why you have been prescribed the diet, you may be given additional restrictions.

If the diet is to clear your bowel before a colonoscopy, you may be told to avoid any gelatin or beverages with red or purple coloring. Dyes can stain the tissue of the intestines, which could be mistaken for blood on a scope.

If you're tempted to add other options on a full liquid diet because you're feeling too limited, talk to your doctor first. There may be cases when the guidelines can be loosened.

Babies and Children

Some adjusting may be needed to make the full liquid diet safe for babies, toddlers, and children. For example, honey should not be given to a child under 1 year old.

While a young child may already be eating a diet with few, if any, solid foods, there are also other considerations for this age group. When creating purées or liquid meals, avoid adding any new foods to your child’s diet. Stick to those you have already introduced.

To ensure your child has a balance of nutritious liquids, you may want to limit how much milk they drink, as it can be very filling. Adding electrolyte drinks or ice pops can also help prevent dehydration. 

Recap

Juices, eggs, grains, and even meat can work in a liquid-only diet so long as they are thinned, melted, or strained to a liquid, lump-free consistency. You may need to drink your meals six to eight times per day to feel full and get all the nutrients you need.

Considerations

Following a full liquid diet may present some challenges. You may need to do some extra planning to fit liquid-only meals into your daily life. These changes may take some getting used to for you and your family.

General Nutrition and Safety

In general, you should aim to consume between 1,350 and 1,500 calories and 45 grams of protein per day on your full liquid diet. Your doctor or dietitian may adjust these goals if you need to be on a full liquid diet for a long time.

Even if you don't feel full, you still might not be getting enough fiber or vitamins and minerals. But with careful planning, this diet can be plenty nutritious and satisfying.

Depending on how long you need to stick to liquids only, you may need to check in with your medical team often. They will monitor you for weight loss and take blood samples to ensure you are getting enough nutrients.

In some instances, your medical team may include a dietitian or nutritionist who will help you design meals that meet your nutrition needs. You can also seek the advice of these specialists on your own.

Sustainability and Practicality

If you’re on a liquid diet while you’re recovering from an illness, injury, or surgery, you might not feel up to the work required to prepare meals. Friends and family may be willing to help. If so, make sure they know exactly what you can and cannot eat.

You can also prepare many liquid meals in advance and freeze them. It may be worth it for you to buy a large-capacity food processor or blender so that you can make big batches. Stock up on as many items as you can before your diet starts, especially beverages and any liquid or powder supplements you might need.

Flexibility

While you won’t have the dietary variety you’re used to on a solid food diet, you won’t totally lose your freedom to enjoy your meals.

Dining out on a liquid-only diet usually isn't too difficult, though you may need to order side items rather than entrees, or ask your waiter to modify your order. For example, if you order a soup, you can request the kitchen to remove any chunky ingredients.

Dietary Restrictions

Ask your doctor about how your liquid-only diet might affect any dietary restrictions or health conditions you have. You may need to adjust your diet around these needs.

For example:

  • After gastric surgery, your healthcare provider might tell you to avoid acidic drinks like orange juice or coffee, which can irritate your stomach lining as it heals.
  • If you have kidney or cardiovascular disease, you may need to limit your fluid intake. Your healthcare provider will provide special instructions for your full liquid diet.
  • If you have diabetes and need to follow a full liquid diet, you may need to take extra steps to manage your blood sugar. Ask your healthcare provider how many grams of carbohydrates each liquid meal will need to contain. Supplements like Glucerna may be helpful.
  • If you have gastroparesis, a condition in which the stomach moves food slowly, you may need to avoid any high-fat liquids or additions, such as butter, as these are harder for the body to digest.
  • If you are managing hypertension (high blood pressure) by limiting your sodium intake, continue to avoid adding salt to your food—even in liquid form.
  • If you are lactose intolerant, avoid using cow's milk to thin foods or add calories to your coffee and tea. You'll also need to closely read the ingredients list and labels on liquid nutritional supplements, as many are milk-based.

Cost

You may be able to save yourself some work by purchasing foods that have already been puréed, though fresh options can be pricey (and, in some cases, hard to find). You may find it more cost-effective to purée food yourself at home. 

Baby food is an option but doesn’t come in big enough portions for an adult's meal. You can use strained meat, veggies, and fruit intended for babies as the base for a liquid meal. These are typically a dollar or so per jar, but that can quickly add up.

The kitchen tools that make food prep for a liquid diet easier can be costly too. If you only need something that can handle the basics, you can usually find more affordable options online.

Side Effects

If you need to be on a full liquid diet for more than a few days, you may become constipated from the lack of fiber. Your healthcare provider may recommend you add an over-the-counter powdered fiber supplement, such as Metamucil, to your liquid meals. 

It’s also not uncommon to have frequent, loose stools on a full liquid diet simply because you are not consuming solids. As you begin to return to a solid food diet, your bowel movements should adjust accordingly. 

Weight loss can be sudden and significant, even if you're not on a full liquid diet for a long time. You should start regaining your weight soon after you start eating more calories again.

Because you are consuming fewer calories, vitamins, and minerals, you may feel fatigued, irritable, depressed, or generally unwell. Don't hesitate to tell your doctor if these symptoms make you uncomfortable.

Recap

Aim to consume up to 1,500 calories and 45 grams of protein per day unless your doctor tells you otherwise. Liquid-only diets may cause weight loss, constipation, and other side effects. Let your doctor know if these become bothersome, or if you have a health condition that makes this diet difficult to maintain.

Full Liquid Diet vs. Other Diets

A full liquid diet is similar to other diets used to treat digestive disorders or help you get ready for (or recover from) surgery. However, there are some key differences.

Clear Liquid Diet

A full liquid diet is similar to a clear liquid diet, which is often necessary before surgery and is a required part of the prep for a colonoscopy.

The main difference is that a clear liquid diet only allows fluids that are completely free of particles, such as water, pulp-free apple juice, and broth. Other juices and bullion may be okay as long as they have been thoroughly strained. Thick, opaque fluids are not allowed.

clear liquid diet options

Verywell / Cindy Chung

A 2016 review of nine studies on colonoscopy preparation found that patients who followed a low-fiber diet were better able to stick with their eating plan compared to people on a clear liquid diet. In addition, they noted no differences in the quality of their preparation or adverse effects.

A full liquid diet falls somewhere between a low-fiber and clear liquid diet. If you find that following a full liquid diet is too difficult, it may be worth asking your doctor if there are other options.

Mechanical Soft and Soft (Puréed) Diets

The mechanical soft diet and soft diet are similar to the full liquid diet but have one key difference.

On a mechanical soft diet, foods are excluded based on their texture or consistency, not their type. On a soft diet, you may need to avoid foods that are high in fiber or fat, even if they are easy to chew.

A mechanical soft diet is typically recommended if you're healing from an injury or surgery involving your mouth, jaw, or throat. A soft diet lets your digestive system rest after illness or surgery.

The mechanical or soft diet may be recommended for you as you progress from a liquid diet back to a regular solid food diet.

Dysphagia Diet

If you have trouble swallowing due to dysphagia, your doctor may recommend a special, three-stage diet to help you get back to eating solid food:

  • In stage one, you will only eat food that doesn't require chewing, such as yogurt.
  • In stage two, you can add foods that only require a little bit of chewing, like soft-boiled eggs.
  • In stage three, you can add fruits and veggies that have been mashed or chopped into tiny pieces.

After you've moved through each of the three stages, you'll be ready to resume a solid food diet. 

Recap

You can only have clear, pulp-free liquids in a clear liquid diet. A mechanical diet prohibits foods that need to be chewed, while a soft diet prohibits high-fat or high-fiber foods that are harder to digest. A dysphagia diet starts like a mechanical diet, but allows you to gradually work your way up to chewing more.

Summary

Your doctor may prescribe a liquid-only diet if you are recovering from an injury or illness that makes it hard for you to chew, swallow, or digest food. You may also need to be on a full liquid diet if you are preparing for a medical procedure.

Full liquid diets are usually temporary, but you may need to work with a dietitian if your liquid-only diet will last longer than a few days. This diet tends to be low in calories, fiber, and other nutrients. As a result, you may lose weight, feel fatigued, or have side effects like constipation.

Talk to your doctor if you are having trouble maintaining your liquid-only diet for any reason.

A Word From Verywell

For many people, the most difficult part of a full liquid diet is staying disciplined and not giving into cravings. Whether you need to be on the diet for a few days, or you need to stay with it longer because of a health condition, try to stay focused on the diet's long-term benefits for your health and recovery. You might be surprised how many liquid-only cookbooks are out there; embrace the newness of the full liquid diet to try new recipes you may never have before.

Frequently Asked Questions

  • How much protein powder should someone add to a full liquid diet?

    Most people on a liquid diet are able to consume enough protein for the duration of the diet, but adding protein powder can help meet these needs. The general protein recommendation for a full liquid diet is at least 45 grams of protein per day. If you are unable to get this much, add protein powder to meals to make up the difference.

  • How long can someone safely be on a full liquid diet?

    How long someone should stay on a liquid diet depends on the individual person, but most people only need it for five days to two weeks. It is important that a physician or dietitian supervise the diet.

  • How much liquid should someone consume daily on a liquid diet?

    Adults should consume 2 to 3 quarts of liquid every day on a liquid diet.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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