What is a Full Liquid Diet?

In This Article

As the name implies, the full liquid diet is one where only liquids—or foods that turn into a liquid at room or body temperature—are allowed. A liquid-only diet is meant to be a temporary measure while you are under a doctor's care.

Benefits

If you’re having trouble chewing and/or swallowing your doctor may recommend a full liquid diet. If you can’t chew or swallow properly, you are at risk for choking or aspiration when you eat or drink.

After dental work or an injury involving your jaw, you may have open wounds in your mouth from incisions or missing teeth. Sticking to a liquid diet until the pockets have closed will help prevent food particles from getting stuck in them, which can lead to infection. 

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 before. This will help make sure no undigested food is left in your gastrointestinal tract, which could affect the results.  

You may also need to be on a liquid diet to prepare for a medical procedure. Having only clear liquids before surgery is usually required to reduce the risk of aspiration. 

full-liquid-diet
Illustration by Joshua Seong. © Verywell, 2018.

How It Works

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 on a clear liquid diet, you are limited to fluids that are completely clear, such as water and broth. The full liquid diet allows you to have thicker fluids that aren’t completely see-through, such as milk, fruit juice, shakes, and smoothies. 

Your doctor may give you permission to have other foods, such as strained purées or yogurt. If you have a medical condition that's influenced by what you eat and drink, you may have additional dietary restrictions.

Full liquid diets have specific challenges and concerns; for example, they tend to be lower in calories compared to other modified diets. It can be difficult to get enough nutritious calories each day while you're on a liquid-only diet.

Your doctor will provide instructions which you will need to follow closely. If you aren't sure how many calories you need to eat a day, you may want to make an appointment with a registered dietician or nutritionist.

Duration

The full liquid diet is generally only prescribed for a few days to help you transition back to your normal diet. It’s rarely required for longer than two weeks (as may be the case prior to bariatric surgery or while you're recovering from a fractured jaw).

Due to its restrictive nature, you should only follow a full liquid diet for a short time and while you are under a doctor’s care. You may also use another modified diet, such as the mechanical soft diet, as a “stepping stone” to help you ease back into eating solid food.

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 liquid diet-friendly. Melting, thinning, straining, or puréeing fruits, vegetables, cheese, and even meat can help you stay nourished and satisfied.  

Compliant Foods

  • Fruit and vegetable juice (no pulp)

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

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

  • Melted cheese

  • Honey, syrup, sugar

  • Coffee, tea, broth, water, soft drinks, sports drinks, or electrolyte-replacement drinks

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

  • Milkshakes, malts, smoothies, pudding

  • Gelatin, ice pops, ice cream, frozen yogurt, sorbet (no nuts, candy, solid toppings)

  • Powdered protein, dry milk, other nutritional supplements

  • Liquid dietary supplements (Ensure, Glucerna, Boost)

Non-Compliant Foods

  • Meat (unless approved cooked and strained)

  • Nuts and seeds

  • Raw fruits and vegetables

  • Solid cheese

  • Soft or mashed food (potatoes)

  • Soups or stews with noodles, meat, or vegetables

  • Whole pasta or rice

  • Cereals, granola, oats

  • Bread

  • Potato chips, crackers, pretzels, popcorn

  • Hard or chewy candy 

  • Applesauce

  • Muffins, cakes, cookies, pastries

  • Tofu, meat substitutes

  • *ALL other solid foods unless specifically approved by your doctor

Fruits and Vegetables: Fruit and vegetable juice is allowed on a full liquid diet as long as it’s been strained to remove any solids (like pulp). 

Mashed potatoes and other types of vegetable mash may be approved if they are thinned. You can blend with butter, gravy, or sauces, season to taste, and thin with water or broth. 

Clear soups and broths are allowed and you can have creamed soups as long as they do not contain solid pieces of pasta, vegetables, or meat.

Grains: Cooked cereals can be thinned with water or milk, then strained. Cream of Wheat and rice are also easy to thin. If you’re trying to add nutrition, use whole milk or creamer to blend instead of water or skim milk. 

Dairy: Milk or lactose-free alternatives are approved. Drink by the glass and/or add to smoothies and shakes for extra nutrition. Dairy-free milk can also be used to thin oatmeal and other thicker foods.

Powdered milk is a versatile option that can be added to cereals, soups, and eggs. You can boost the protein of regular milk by mixing it with dry skim milk before using it to create liquid meals. 

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. 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 (puréed, thinned, and strained). Mix meat with potato flakes and milk before or after cooking to give it the right consistency for a liquid diet.

Nut butter is a good source of healthy fats and protein that can be easily added to shakes or smoothies. Eggs, egg whites, or Egg Beaters 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.

If you need to add calories, try topping ice cream, pudding, malts, or milkshakes with fruit blended with whipped cream. 

Beverages: Any clear broths, juices, or other drinks are approved on a full liquid diet. However, fruit and vegetable juice may have more fiber than your doctor has recommended for you.

Making your own juice with a high-speed bullet blender or juicer allows you to control the consistency. You can also pour the juice through a mesh sieve or tea strainer to catch any lingering residue.

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 chips, nuts, or mulling spices.

Recommended Timing

One challenge of a liquid diet is knowing whether you’ve consumed adequate nutrition in a given day. As a general rule, have enough to feel satisfied (as you would if you were eating solid food). 

However, 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 adequately 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 frequently as 6-8 times a day.

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

Cooking Tips

The easiest way to thin soft food (such as mashed potatoes) 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 blenders and food processors can be a big help if you’ll be making liquid meals for yourself at home. Not only can it purée fruits and veggies, but on a lower setting, you can use a blender 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 

A full liquid diet may need additional modifications if you have other medical conditions or dietary needs.

For example, after gastric surgery, your doctor might tell you to avoid acidic drinks like orange juice or coffee which can irritate the lining of your stomach as it heals.

If you have kidney or cardiovascular disease, you may have been told to restrict your fluid intake. If you need to go on a liquid diet, your doctor will provide special instructions.

If you have diabetes, ask your doctor how many grams of carbohydrates each liquid meal will need to maintain your blood sugar levels. Supplements like Glucerna may be helpful.

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

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

If you have food allergies or adhere to a special diet, be sure to carefully check the ingredients of any powders, supplements, or mixes you use. You may be able to find specific products that suit your diet, such as gluten-free or vegan-friendly options. 

Considerations

Whenever you have to make a change to your diet (even if it's only temporary) you'll have to think about how it will affect other areas of your life. Aside from the obvious aspects like grocery shopping and meal preparation, you'll also want to think about your daily responsibilities at work and at home. For example, planning meals for your family.

General Nutrition

Full liquid diets can be carefully nutritionally balanced, but they tend to be low in calories. The typical goal is around 1,500 calories per day, but may be as low as 800 calories

While liquid meals can be filling and you may not feel hungry, the diet doesn’t contain adequate fiber and lacks essential vitamins and minerals. 

You will most likely only need to be on a liquid-only diet for a short period of time. If you need to be on the diet for longer, your doctor may have you add liquid dietary supplements, such as Ensure, to your daily meal plan.

You can also increase the caloric, fat, and protein content of liquid meals by adding powdered supplements, butter, eggs, or dry milk. 

Sustainability and Practicality

If you’re on a liquid diet while you’re recovering from an illness, injury, or surgical procedure, you might not feel up to the work required to prepare meals. If friends and family can help, make sure they know what the requirements of your diet are. 

You can also prepare many liquid meals in advance and freeze them. Stock up on as many items as you can beforehand, especially beverages and supplements.

Safety

It’s unlikely that you’ll need to be on a full liquid diet for a long period of time. The exception may be people with medical conditions who utilize a liquid-only diet to manage acute "flares" of symptoms or complications. However, they only do so while being closely monitored by their doctors. 

If you need to be on a liquid diet more than once, or for a longer stretch of time than you planned, you may find it helpful to work with a registered dietician or nutritionist. 

Your entire medical team will monitor you for weight loss and nutrient deficiencies which can occur when you are on a restricted diet. These professionals can help you design meals with enough calories and nutrition to sustain you, as well as recommend any supplementation you may need.

Flexibility

While you won’t have the dietary variety you’re accustomed to on a solid food diet, you won’t be completely restricted on a liquid-only diet.

It's even possible to find options that are suitable for a full liquid diet when you're dining out. Milk, soup, and ice cream can be found on the menu of most casual dining restaurants, and those that offer breakfast may have juices and smoothies.

You can even hit your favorite drive-thru. Most fast food restaurants have a wide range of beverage choices, including high-calorie milkshakes.

Dietary Restrictions

Ask your doctor about how other dietary restrictions or health conditions you have will be affected by being on a liquid-only diet, as well as how a full liquid diet may need to be adjusted in response to these needs.

For example, if you follow a diet to manage gastroparesis, you may need to avoid any high-fat liquids or additions, such as butter. If you are managing hypertension with a sodium-restricted diet, you would want to continue to avoid adding salt to your food—even in liquid form.

If you are lactose intolerant, you'll want to avoid using cow's milk to thin foods or add calories to your coffee and tea. You'll also need to closely inspect the list of ingredients and labels on liquid nutritional supplements, as many are milk-based.

While most fruit and vegetable juices can be strained, you may need to avoid any high-fiber juice such as prune juice if you are on a low-fiber diet.

Support and Community

Even if you can recreate many of your favorite flavors on a liquid-only diet, you may quickly tire of not being able to eat solid food. If you’re also healing from an illness, injury, or surgery, you may also be trying to manage pain and other symptoms. 

Friends, family, or other caregivers are an important part of your recovery. Beyond the support from your medical team, you may need practical help at home (such as with meal prep) as well as emotional support from the people who care about you.

If you are on a liquid diet due to a specific condition, especially if it's chronic, you may find support from other patients makes a world of difference to how you feel about your own situation. Even just being able to share your feelings and worries with someone who has been through it can mean a lot.

There may be in-person support groups near where you live or the hospital where you are treated, but you can also look online for social media network groups for patients or websites with reliable resources. 

Cost

You’ll likely be able to continue to buy many of the groceries you typically do, such as fresh produce, meat, and pasta. The difference is how you’ll need to prepare these foods for a liquid diet. 

You may be able to save yourself some work by purchasing foods that have already been puréed. Although baby food doesn’t come in portions adequate enough for an adult diet, jars of strained meat, veggies, and fruit can make a good base for a liquid meal.

While it's easy and convenient, the cost of baby food quickly adds up. You may find it's more cost-effective to purée food yourself at home. 

The kitchen tools that make food prep for a liquid diet easier, such as a blender or food processor, can be expensive. If you only need something that can handle the basics, you can usually find more affordable options—especially if you shop 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 doctor 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, as you are not consuming any solid food. As you begin to return to a solid food diet, your bowel movements should adjust accordingly. 

Weight loss, which may be sudden and significant, is also possible—even if you're not on a liquid diet for a long time. Once the caloric deficit created by the low-calorie diet is corrected, weight is typically restored. 

The low caloric value and lack of essential vitamins and minerals may cause you to feel fatigued or unwell. You may feel depressed and irritable—emotions which can be heightened by undernutrition.

If you will be on a liquid diet for a longer stretch of time, you will likely need to supplement nutrients to prevent deficiencies. Your doctor may recommend a multivitamin or specific vitamins, such as B12. 

Energy and General Health

If you are feeling run down from eating fewer calories than your body is used to, there are many ways to increase the calorie, fat, and carbohydrate content of your liquid meals.

Powdered milk can be added to creamed soups and you can sweeten foods with sugar or liquid sweeteners such as honey or corn syrup. Adding butter or margarine to hot cereal or potato blends is another option.

If you can't use real sugar artificial sweeteners are also allowed on a full liquid diet.

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 clear liquid diet or surgical liquid diet only allows fluids with no particulates, such as water, clear juice like apple juice, and broth. Other juices and bullion may be acceptable as long as they have been thoroughly strained.

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

clear liquid diet options
Illustration by Cindy Chung, Verywell

Mechanical Soft and Soft (Puréed) Diets

The mechanical soft diet and soft diet are similar but have one key difference. On a mechanical soft diet, foods are excluded based on their texture or consistency, not their ingredients. On a soft diet, you may need to avoid foods that are high in fiber or fat even if they are easy to chew.

The two diets share many of the same approved foods but are used for different reasons. A mechanical soft diet may be needed if you're healing from an injury or surgery involving your mouth, jaw, or throat. A soft diet rests your digestive system after illness or surgery.

In some cases, you might use both diets to progress from a liquid diet back to a regular solid food diet. 

Dysphagia Diet

If you have dysphagia, your doctor may have you use a special diet three stages to help you progress back to eating solid food.

During the first stage, you can only have food that doesn’t need any chewing, such as yogurt. In the next stage, you can add foods that only need a little bit of chewing, like soft-boiled eggs. In stage three, you can add fruit and veggies that have been chopped into tiny pieces or mashed up.

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

If you have dysphagia, your doctor might instruct you to sit up when you eat and drink. You may need to stay sitting upright for at least 30 minutes after eating or drinking. Doing so can help prevent discomfort but also keeps you safe.

If you have trouble chewing or swallowing, you may be more likely to choke or breath in food particles or liquids (aspiration). Accidentally breathing in particles or drops of fluid puts you at risk for developing aspiration pneumonia, which can be serious.

Your doctor might also give you swallowing exercises to practice at home or show you how to safely crush medications that are in pill form. 

A Word From Verywell

A full liquid diet is only used in certain circumstances, which are usually temporary. You may need to be on a liquid diet to prepare for a procedure, heal from an injury to your jaw, or recover from surgery on your mouth, throat, or digestive tract. Some people with digestive disorders may need to use a liquid-only diet from time to time to allow their bowel to rest.

You will need to be under medical supervision while on a full liquid diet. Since the diet is generally low in calories and doesn’t provide adequate long-term nutrition, your doctor may have you add vitamins or nutritional supplements. It may be helpful for you to work with a registered dietician or nutritionist. They can show you how to plan liquid meals that meet your daily nutritional requirements.

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