Full Liquid Diet: What to Eat, Benefits, and Limitations

A full liquid diet includes foods like yogurt, strained soups, dairy, dairy alternatives, fruit juice, and more. The diet is made up of only fluids and foods that are usually liquid, as well as foods that turn to liquid when at room temperature, like ice cream and milkshakes.

A full liquid diet may be the next step after a clear liquid diet (eating only foods you can see through, like tea, broth, and gelatin) following a gastrointestinal surgery or injury. It may also help if you have swallowing or chewing problems. There are benefits and limitations of a full liquid diet.

What Can You Eat on a Full Liquid Diet?

The following table outlines foods that are allowed and foods that are excluded on a full liquid diet. Some foods are excluded because they are solid or their textures are too thick and lumpy.

Fruits and vegetables: Apple, grape, pear, tomato, and strained orange juice are good options. Avoid high-fiber juices such as prune juice, nectars, and orange juice with pulp. Vegetables can be cooked into a soup, pureed, and strained.

Grains: Grains are not usually recommended on a full liquid diet. In some cases, cooked cereals (like farina or rice) can be thinned with water or milk and then strained, but check with your healthcare provider first. To add calories and nutrients, prepare the cereal with whole milk or creamer instead of water or skim milk. 

Dairy: Milk or lactose-free alternatives are approved for a full liquid diet. You can drink it by the glass or add it to smoothies and shakes. Yogurt is also allowed. Regular yogurt works well as a base for sweeter-tasting liquid meals, while Greek yogurt can be a good base for more savory recipes. You can also use butter or margarine to add calories and fat to your meals. 

Protein: Protein shakes and powders, nonfat dry milk, instant breakfast powders, and powdered egg whites are recommended for adding protein to the full liquid diet. Check with your healthcare provider if you can include cooked eggs or meat pureed to a liquid or baby food consistency. Nut butter is sometimes allowed and can provide a good source of healthy fats and protein.

Desserts: Ice cream, frozen yogurt, and ice pops are approved on a full liquid diet as long as they do not contain nuts, candy, pulp, or other hard pieces. Puddings and custards can be thinned to a liquid consistency with milk.

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 approved as long as they do not contain solid pieces such as chocolate flakes or mulling spices.

Benefits

The full liquid diet is one that places little stress on your gastrointestinal (digestive) tract but provides more flavor and nutrition compared to a clear liquid diet.

The full liquid diet requires no chewing. It includes clear fluids, like water and apple juice, along with thicker ones, like milk, shakes, and smoothies. Your healthcare provider may also include thicker foods like yogurt or puddings that contain no lumps or solid pieces.

A full liquid diet aims to promote the healing of your digestive tract, which includes everything from your mouth and throat to your colon and rectum. It is not the same as the clear liquid diet that is used before gastrointestinal procedures like a colonoscopy.

Compared to a clear liquid diet, a full liquid diet includes foods that are nutritionally dense with higher levels of protein and carbs. While you may still be shy of your optimal nutritional needs, the diet is a good stopgap until you are better able to eat soft or solid foods.

Limitations

The average adult in the United States requires between 1,600 and 3,000 calories per day (and between 225 and 325 grams of carbs per day) to function normally. It is difficult to achieve this level of calories following a full liquid diet.

A full liquid diet may be inadequate in fiber and certain vitamins. It can also be monotonous and somewhat unappetizing or unsatisfying.

A full liquid diet isn't suitable for long-term use unless nutrition supplementation is provided by a registered dietitian or healthcare provider.

Who Goes on a Full Liquid Diet?

Your healthcare provider may prescribe a full liquid diet if you have certain medical conditions or are recovering from certain medical injuries or procedures.

Indications for a full liquid diet include:

• Swallowing problems (dysphagia)
• Chewing problems
• Severe mouth or throat sores
• Jaw injuries
• Digestion problems (such as gastroparesis and bowel strictures)
• Recovery from a gastrointestinal infection, injury, or illness
  
• Recovery from gastrointestinal, dental, oral, or weight loss surgery
  

Goals of a Full Liquid Diet

The aim of a full liquid diet is to consume enough nutrition without placing stress on the digestive tract. This may be easier said than done, given that certain digestive disorders can make you feel fuller faster or cause nausea even after a few bites.

To meet the goals of a full liquid diet, you need to focus on:

• How much you eat: As a general rule, eat enough to feel satisfied. To avoid overtaxing your system, eat several smaller meals per day instead of three big ones.
• What you eat: The diet should also include a variety of six or seven different foods that are nutritionally dense. A registered dietitian or nutritionist can help you with this.
• Nutrition: To ensure your nutritional needs are met, keep a food diary of everything you eat and use a nutrition app to calculate your daily calories, protein, and carb intake.

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

Exceptions may be made for people who are preparing for weight loss surgery, recovering from a fractured jaw, or managing chronic conditions like Crohn’s disease.

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

Sample Menu

The following is a sample menu for a full liquid diet:

Full Liquid Diet 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 an over-the-counter fiber supplement, such as Metamucil, to relieve your symptoms. 

You might also 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 improve. 

Can You Lose Weight on a Liquid Diet?

You can lose weight on a full liquid diet if you do not consume enough calories. Weight loss may be sudden and significant even if you’re not on the diet for a long time.

To overcome this, ask your healthcare provider about high-calorie protein shakes like Ensure. You should start regaining weight once your calorie intake increases.

Full Liquid Diet Modifications 

A full liquid diet may need to be adjusted based on your age, general health, and any medical conditions you may have.

For instance:

• Gastric surgery: You may need to avoid acidic drinks like orange juice or coffee, which can irritate your stomach.
• Kidney or cardiovascular disease: You may need to limit your fluid intake to prevent fluid retention and disease complications.
• Diabetes: You may need to take extra steps to manage your blood sugar. This includes monitoring your intake of carbohydrates that can raise your blood sugar.
• Gastroparesis: With this condition in which food moves through your intestines slowly, you may need to avoid high-fat full-liquid foods that are hard to digest.
• Hypertension (high blood pressure): You may need to limit your sodium (salt) intake.
• Lactose intolerance: You should avoid cow’s milk and other dairy products and find other quality sources of protein, calcium, and vitamin D.

Babies and Children

Some adjustments 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 of age.

When creating purées or liquid meals, avoid adding new foods to your child’s diet. Stick to those they already enjoy and indulge them with treats like ice cream or custard to add additional calories.

Speak with their healthcare provider about how much milk a child should drink, as it can be very filling. Adding electrolyte drinks or ice pops can help prevent dehydration if the child experiences diarrhea.

Tips and Considerations

Following the 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 time to get used to.

Here are some tips that can help:

• Stock up your fridge and pantry: Stock up on as many items as you can before your diet starts, especially beverages and powder supplements you might need.
• Purée foods at home if you're on a budget: You may be able to save yourself some work by purchasing foods that have already been puréed, but these can be pricey and hard to find. You may find it more cost-effective to purée foods at home.
• Make food in advance: For convenience, you can also prepare many liquid meals ahead of time and freeze them.
• Try different ways to thin soft foods: The easiest way to thin soft foods is to add water or milk. If a food doesn’t fully liquefy, apply a little heat or microwave it. Pasta, rice, and potatoes can be cooked until very soft and then thinned with water, butter, or gravy.
• Invest in kitchen appliances: 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 pulse thicker foods like oatmeal into a safe consistency.
• Utilize puréed baby food: This can be a convenient option, but keep in mind that baby food doesn’t come in big enough portions for adults (and, at a dollar or so a jar, can end up being costly). Even so, you can use them as the base for a liquid meal.
• Supplement your diet with nutritional shakes: While nutritional shakes like Ensure and Glucerna are costly, they can add a good boost of protein and nutrition to better meet your daily needs. While the added cost of nutritional shakes may be well worth the investment, they should not be used as the sole source of nutrition.
• Let others know about your diet: Friends and family may be willing to help with grocery shopping and/or preparing meals. If so, make sure they know exactly what you can and cannot eat.

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.

Mechanical Soft Diets

A mechanical soft diet is one that doesn’t require much chewing. With that said, certain soft foods may be excluded based on their texture or consistency. These include 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. It also allows your digestive system to rest after an illness or surgery.

A mechanical soft diet may also be recommended as you progress from a full liquid diet back to regular solid food.

Dysphagia Diet

If you have trouble swallowing, 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 vegetables that have been mashed or chopped into tiny pieces.

After you’ve moved through all of these stages, you should be ready to consume a normal solid food diet.

Summary

Your healthcare provider may prescribe a full liquid diet if you are recovering from an injury or illness that makes it hard for you to chew, swallow, or digest food. It may also be recommended after gastrointestinal surgery to heal you better.

Full liquid diets are usually used for a few days and up to two weeks. Side effects include constipation, diarrhea, fatigue, tiredness, and weight loss. If you need a full liquid diet for more than a couple of weeks, work with your healthcare provider or a registered dietitian who can help you build a nutritionally balanced food plan.