A liquid diet may be indicated to help prevent dehydration, improve digestion, and avoid choking in people who are unable to eat solid foods, such as people with conditions like multiple sclerosis (MS) or Parkinson's disease and those who have suffered a stroke. It may also be indicated post surgery.

A liquid diet may also be prescribed as part of exam prep for procedures like colonoscopy, which is used to examine the bowels and evaluate intestinal health.

A liquid diet may include foods like porridge, strained fruit juice, soup, broth, tea, and pudding. Because liquid diets can be very restrictive, the use of nutritional supplements may also be necessary while on this diet.

Indications for the diet

A liquid diet may be indicated to help prevent dehydration, improve digestion, and avoid choking in people who are unable to eat solid foods, and may be prescribed for the following conditions:

Parkinson's disease;
Multiple sclerosis (MS);
Stroke;
Anorexia;
Post-op following bariatric surgery, head and neck surgery, or oral surgery;
Gastrointestinal (GI) problems like diarrhea and vomiting.

A liquid diet can also be used before surgery or in preparation for exams like a colonoscopy procedure.

Weight loss

A liquid diet can help with weight loss because it includes healthy foods like fruit, vegetables, and lean protein. This diet is low in fiber, however, which can lead to increased hunger and eating more throughout the day.

It can also be common to regain the weight lost after returning to a normal diet. This is because a liquid diet does not focus on behavioral changes that can help a person make healthier food choices and avoid the "yo-yo effect" of dieting.

For this reason, it is recommended to consult a registered dietitian who can perform a full evaluation and design a personalized weight loss diet tailored to your own individual needs.

How to follow

A liquid diet can be divided into two types: a clear liquid diet and a full liquid diet, each with their own indications.

1. Clear liquid diet

A clear liquid diet helps prevent dehydration while allowing the digestive system to rest. It may be indicated in cases of nausea and vomiting as well as pre- and post-surgery. It can also be used as a bridge between parenteral (IV) nutrition and returning to solid foods.

A clear liquid diet does not contain fiber and is low in carbohydrates, protein, and fat. It is generally only recommended for a maximum of 3 days. Foods that are allowed as part of a clear liquid diet include:

Fat free chicken, beef, or vegetable broth;
Drinks like water, tea, and strained fruit juice with no pulp (such as apple juice);
Gelatin (Jell-O);
Soft drinks and sports drinks;
Ice pops (Popsicles).

All types of solid food should be avoided in this diet, including milk/dairy products, cereals, and fruit juice with pulp.

2. Full liquid diet

A full liquid diet is indicated for people who have difficulty chewing or swallowing solid foods, such as people with conditions like anorexia, Parkinson's disease, and multiple sclerosis (MS). This diet may also be prescribed pre- or post-surgery and in preparation for certain procedures or exams.

Foods that are permitted as part of a full liquid diet include:

Cooked cereals, like cream of wheat and instant oatmeal;
Blended/strained soups, made with vegetables, lean protein, and legumes;
Drinks, including smoothies and vegetable juice;
Dairy, like milk, yogurt, and ice cream (with no chunks or candy pieces);
Protein supplements, like Ensure or Boost.

Foods to avoid in a full liquid diet include solid foods, whole grains, sugar, nuts and seeds, raw and whole vegetables, whole fruits, and fatty foods.

Meal plan

The following table is one example of a 3-day meal plan following a full liquid diet:

Meal	Day 1	Day 2	Day 3
Breakfast	1 bowl cream of wheat	1 bowl instant oatmeal	1 bowl cream of rice
Morning snack	1 small glass of strained mango juice	1 small fruit smoothie	1 small glass of coconut water
Lunch	2 ladles of potato, carrot, broccoli, spinach, and chicken soup (blended well and strained)	2 ladles of squash, bean, carrot, zucchini, kale, and beef soup (blended well and strained)	2 ladles potato, zucchini, carrot, and chicken soup (blended well and strained)
Afternoon snack	1 small glass strained strawberry juice without added sugar	1 sugar-free Jell-O	1 small glass strained orange juice without added sugar
Dinner	2 ladles vegetable beef soup (blended well and strained)	2 ladles chicken vegetable soup (blended well and strained)	2 ladles chicken or beef vegetable soup (blended well and strained)
Evening snack	1 cup chamomile tea (no sugar) + 1 sugar-free Jell-O	1 small glass strained papaya juice	1 cup lemon balm tee (no sugar) + 1 sugar-free Jell-O

It is important to remember that a liquid diet will vary based on the indication for the diet as well as a person's overall health. A doctor or registered dietitian can perform a full evaluation and prescribe an adequate diet to meet your own individual needs.

Because liquid diets can be very restrictive, your doctor or registered dietitian may recommend the use of additional nutritional supplements while on a liquid diet.

Side effects

Liquid diets are very restrictive and can cause symptoms like weakness, dizziness, headache, nausea, irritability, dehydration, low blood pressure, and blurred vision.

When continued for a prolonged period of time, liquid diets can also lead to nutritional deficiencies and cause alterations in the gut flora.

How To Follow a Liquid Diet: Indications + Meal Plan