A liquid diet involves consuming only liquids or foods that turn into liquid at room temperature. While it's sometimes medically prescribed, people also use it for weight loss. This article explores the various types of liquid diets, their potential benefits and risks, and who should avoid them.
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. Liquid diets are nutrition programs that require you to get either some, most, or all of your daily calories from liquids, rather than solid foods. When following a liquid diet, you’ll eat nothing but liquids and foods that turn into liquids, like ice cream. Solid foods are not allowed. A full liquid diet consists of consuming only liquids or foods that turn into liquid at room temperature, such as yogurt, strained soups, fruit juice, ice cream, and milkshakes.
Types of Liquid Diets
There are different kinds of liquid diets. While there are many liquid diets, most can be grouped into one of the following categories.
Clear Liquid Diet
A clear liquid diet is something a doctor may put you on for a short while. As the name implies, clear liquid diets only allow the consumption of clear liquids, such as water, apple juice, tea, certain sports drinks, and broths. You’re often asked to follow one before a medical procedure or if you're having some digestive issues. Clear liquids are typically easy to digest and do not leave much undigested material in your intestines. These diets may be prescribed before or after certain surgeries or if you have digestive problems. 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.
Full Liquid Diet
A full liquid diet includes only liquids and foods that turn into liquid at room temperature. A healthcare professional may prescribe this diet before or after certain medical tests and surgeries. Full liquid diets are prescribed for similar reasons to clear liquid diets, but they are less restrictive than clear liquid diets. They allow most beverages, as well as foods that become liquid at room temperature, such as popsicles, Jell-O, pudding, syrups, and some shakes. The full liquid diet is designed to provide your body with nutrition while minimizing stress on the digestive system. Liquids take less energy to break down and absorb. A full liquid diet may also be used if you’re having trouble chewing or swallowing food. For example, if you’ve had throat surgery, your surgeon may prescribe a full-liquid diet until you can swallow solid foods. You must avoid solid foods for the recommended treatment course if prescribed a full liquid diet. In some cases, foods like cream of rice, oatmeal, grits, strained meats, and pureed potatoes may be allowed. You need to avoid most solid foods when following a full liquid diet.
Read also: Is a liquid diet right for you?
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. A clear liquid diet has limitations in that it delivers low calories and low levels of carbohydrates, possibly starting as low as 50 grams a day after bariatric (weight loss) surgery. Compared to a clear liquid diet, a full liquid diet includes foods that are nutritionally dense with higher levels of protein and carbs.
Meal Replacements
Some liquid diets involve meal replacement shakes, which are consumed in place of solid foods. People choose to go on other types of liquid diets for weight loss. Typically, they’re limited to fruit or vegetable juices, or shakes. Numerous companies sell these shakes for weight loss purposes. Meal replacement shakes are often lower in calories than typical meals. They can replace one or multiple meals each day. They are designed to contain all the nutrients your body needs to function, including macronutrients (protein, carbs, and fat) and micronutrients (vitamins and minerals). Some weight loss programs use these shakes to account for your entire calorie intake for up to several months.
Detox Diets and Cleanses
Other liquid diets include detox diets or cleanses, which require the consumption of certain juices or drinks that supposedly remove toxic substances from your body. Unlike meal replacement shakes, these programs typically rely on a few natural ingredients like juices from certain fruits and vegetables and other botanical ingredients. Because of this, these diets may not contain all the nutrients your body needs.
Liquid Diets and 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. Liquid diets often contain fewer calories than diets consisting of solid foods. For a liquid meal replacement diet, the total number of daily calories may range from 500-1,500. However, these diets are often just one phase of an overall weight loss program.
Research has shown that both low-calorie (1,200-1,500 calories per day) and very low-calorie (500 calories per day) diets using liquid meal replacements can be effective for weight loss. While very low-calorie diets can lead to greater weight loss, they may also lead to greater risks, such as an increased risk of gallstones in some individuals. It is important to note that people participating in studies on low-calorie liquid diets are typically monitored closely by medical personnel. What’s more, many of these programs are not meant to be followed in the long term.
Read also: Explore the pros and cons of liquid diets
How to approach
When following the full liquid diet, you may present some challenges. You may need to do some extra planning to fit liquid-only meals into your daily life.
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.
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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.
Drawbacks and Risks
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. 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.
Even in studies showing impressive results from liquid meal replacements, solid foods were reintroduced after several weeks or months. Medically prescribed liquid diets like the clear liquid diet or full liquid diet are not meant to be followed in the long term. Similarly, cleanse and detox programs may involve periods during which only certain juice mixtures are consumed for days or weeks. Short-term, low-calorie diets can cause you to lose body weight quickly due to the loss of carbs and water, both of which are normally stored in your liver and muscles.
Thus, much of the weight you lose during these short-term liquid diets may not be due to fat loss. Once you resume a normal diet, you will likely regain much or all of the weight that you lost as your carbohydrate and water stores are replenished. Short-term crash diets don’t typically lead to lasting weight loss because they don’t do anything to change your permanent eating habits. For these reasons, overly restrictive diets that don’t allow any solid foods are not generally recommended.
Who Should Avoid Liquid Diets?
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.
Several groups of people should not consider a liquid diet, such as pregnant or nursing women, children and adolescents, and those who are underweight. Not to mention, there are financial considerations. Commercial meal replacement shakes can often be more expensive than traditional solid foods.
How to Make a Liquid Diet Safer
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. If you choose to go for it, choose beverages that have protein, carbohydrates and fat to help you stay full and allow vital nutrients to be absorbed. Swapping juices for smoothies can help. Consider having one liquid meal per day instead of all three.