Liquid Diet

What Is a Liquid Diet?

As the name suggests, a liquid diet means you're getting all, or at least most, of your calories from drinks. There are different kinds.

A clear liquid diet is something a doctor may put you on for a short while. You’re often asked to follow one before a medical procedure or if you're having some digestive issues. You won’t get the calories and nutrients you need with one of these diets, so you can’t be on them for long and shouldn’t do them without medical supervision.

People choose to go on other types of liquid diets for weight loss. Typically, they’re limited to fruit or vegetable juices, or shakes. These drinks may replace all of your meals or just one or two meals (usually breakfast and lunch). You also get snacks on some of these plans.

These diets can cut the calories you take in and can help you lose weight, but you shouldn’t stay on them for very long. Talk to your doctor before you go on a liquid diet. You’ll need to make sure you get enough important nutrients, like fiber and protein.

Do liquid diets work for weight loss?

Liquid diets can work, like any diet that gives you fewer calories than you use. These diets can help by taking the guesswork out of portion control. They’re also beneficial if you have trouble chewing food.

But the results may not last. When you drastically cut calories, your metabolism slows to save energy. Unless you change your eating habits, you're likely to regain the weight you lost after you go off the liquid diet.

Some liquid diets work better over the long term than others. Diets that include both solid food and liquids can be an effective and convenient way foroverweight people to control the number of calories they eat.

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Liquid Diet Risks

Ideally, liquid diet drinks should give you a balance of nutrients you need throughout the day, but that isn't always the case.

Very low-calorie diets (400-800 calories per day) in particular can be lacking in a balance of protein, carbohydrates, fats, vitamins, and minerals you need and should only be used under medical supervision.

Missing out on essential nutrients can lead to side effects such as fatigue, dizziness, hair loss, gallstones, and heart damage.

Also, if you don't get enough fiber, because you're not eating whole grains, fruits and vegetables, you can get constipated.

You also can lose muscle if you don't get enough protein calories in your diet.

Talk to Your Doctor Before Starting A Liquid Diet

If your doctor prescribes you a liquid diet, they’ll go over what liquids you can have, and how long you should be on it. Make sure you follow their instructions carefully.

If you want to go on one for weight loss, talk to your doctor first about whether a liquid diet is appropriate for you. Pregnant or nursing women, and people who take insulin for diabetes, or anyone with a chronic illness shouldn't go on a liquid diet.

If your doctor gives you the OK to go on one, you should also see a registered dietitian, who can go over it with you and make sure you're getting enough calories and nutrition. Your dietitian might recommend that you take a vitamin or nutritional supplement while you're on the liquid diet.

Before you choose a liquid diet plan, know what you're drinking. If you're considering one of the commercial diets, look at the daily values on the nutrition facts label. Be sure you're getting 100% of all the recommended vitamins and minerals.

Look for a diet that is not too low in calories and contains plenty of protein and fiber to keep you feeling full while you lose the weight gradually. Liquid diets that include a solid meal or two per day, or that teach you healthier eating habits, will be more likely to help you keep the weight off in the long run.

WebMD Medical Reference Reviewed by Neha Pathak, MD on August 25, 2020

Sources

SOURCES:

Andrea Giancoli, MPH, RD, spokeswoman, Academy of Nutrition and Dietetics.

Flechtner-Mors, M. Obesity Research, August 2000.

National Digestive Diseases Information Clearinghouse: "Crohn's Disease."

Yamamoto, T. Inflammatory Bowel Diseases, December 2007.

Southwest College of Naturopathic Medicine and Health Sciences: “The Benefits and Downsides of Liquid Diets.”

Mayo Clinic: “Clear liquid diet.”

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