The clear liquid diet for weight loss is one of the most well-known diets in the world, however, it may be less effective than people think. What is a clear liquid diet? The clear liquid diet restricts the consumption of solid foods and allows for only liquids or very thin pureed foods to be consumed. Clear liquid diets are often used in weight loss programs as an alternative to regular diets.
What Is a Full Liquid Diet?
On a full liquid diet, you consume no solid foods, but some purees are OK
A full liquid diet is one in which you only consume liquids or foods that turn to liquid at room or body temperature (such as soups and milkshakes).
This is considered a middle ground between eating solid foods and following a clear liquid diet, in which you can only consume items that you can see through, such as tea, broth, and gelatin.
There are several reasons why your healthcare provider may recommend a full liquid diet—for example, if you are having digestive problems or are preparing for a colonoscopy, a procedure that screens for colon-related issues.
This article discusses the risks and benefits of a full liquid diet, as well as reasons you may need to follow one. It also includes a list of foods you can and cannot have as part of a full liquid diet.
Types of Liquid Diets
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.
While there are many liquid diets, most can be grouped into one of the following categories.
Some liquid diets involve meal replacement shakes, which are consumed in place of solid foods. 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
Examples of these diets include the Master Cleanse, long-term water fasting and various juicing programs.
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.
Medically Prescribed Liquid Diets
Clear liquid and full liquid diets are examples of diets that are medically prescribed for specific health reasons.
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
These diets may be prescribed before or after certain surgeries or if you have digestive problems.
Full liquid diets are prescribed for similar reasons, 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
SUMMARYLiquid diets replace some or all food with beverages. There are several types, including meal replacement programs, cleanses and medically prescribed liquid diets.
Full Liquid Diet Basics
The full liquid diet allows you to have clear fluids as well as thicker ones, like milk, fruit juice, shakes, and smoothies. Your healthcare provider may also give you permission to have other foods, like yogurt or puréed fruits, so long as there are no lumps or solid pieces.
These will be your only options while on a full liquid diet, which can make it hard to get enough nutrients and calories each day.1 You will need to follow your healthcare provider’s instructions closely to make sure you are still getting all the nutrients your body needs.
A registered dietitian or nutritionist can be a helpful resource, especially if you have additional food allergies or dietary restrictions.
How Do Liquid Diets Help In Weight Loss?
Liquid diets are the go-to diets for many dieters. This is because they help save time, improve metabolic rate, detoxify the body, and support the digestive system, resulting in weight loss and better overall health. Listed below are the ways liquid diets could aid weight loss.
1. Low In Calories
Liquid diets are low in calories as they consist of watery-clear fluids. Studies in The American Journal of Clinical Nutrition showed that very-low-calorie diets, including a liquid diet consisting of no more than 500 calories a day, could be effective in reducing weight. This type of diet could work better compared to a low-calorie diet or a restricted normal food diet
When you consume fewer calories, your body will start using up the stored glycogen or fat as the source of fuel. This, in turn, could lead to weight loss.
A study published in The International Journal of Obesity showed that a low-calorie diet or very low-calorie diet resulted in muscle glycogen depletion for a short period. Body fat also decreased, resulting in weight loss
2. Detoxify Your Body
Liquid diets are an excellent way to detoxify your body.
The juices/broths/smoothies are rich in vitamins, minerals, and dietary fiber. Rat studies have shown that fruit or vegetable juices are rich in antioxidants and can prevent oxidative damage (4).
The dietary fiber helps cleanse the digestive tract and improves gastrointestinal health (5). Both these actions could have a beneficial impact on weight loss.
Liquid food in the juice or smoothie form offers rich nutrition. Remember to drink the juice/smoothie immediately if you are using a centrifugal blender.
Replacing your dinner meal with low-calorie liquid foods improves body composition parameters and may also aid weight loss. In a study, the group of subjects who took a liquid meal replacement seemed to have better weight parameters
Maintaining a balanced calorie intake along with a liquid diet throughout the day can help provide the required nutrients to the body.
4. Easy On The Digestive System
Juices/smoothies/broths are easy on your digestive system. They aid proper digestion, absorption, and excretion. Moreover, the little dietary fiber and water in the liquid diet (by including pulp in juices or smoothies) can keep you full for a long duration. As per one study, a liquid meal replacement was found to have more fiber than a solid meal replacement
You don’t have to wait for the pan to heat up or scroll through recipes online.
You may simply toss all the ingredients into a blender, and your breakfast/lunch/dinner is ready.
This is a major advantage, more so if we tend to skip a meal or order unhealthy food as cooking could be a time-consuming process. Starving or eating unhealthy could only lead to weight gain in the long run.
These are the many advantages of a liquid diet. The diet is available in different types, and in the following section, we will explore those.
How Much Liquid Should You Consume?
Aim to consume at least 64 fluid ounces by the end of each day.
That can easily be measured. But one challenge of a liquid diet is knowing whether you’ve consumed enough nutrition on a given day. As a general rule, have enough to feel satisfied.
That said, 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 fully 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 often as six to eight times a day.
How Long Can You Stay on a Full Liquid Diet?
The full liquid diet is generally prescribed for only a few days to help you transition back to your normal diet. It’s rarely used for longer than two weeks.
Exceptions may be made for people who are preparing for bariatric (weight loss) surgery, recovering from a fractured jaw, or who use the diet to manage flare-ups of certain health conditions, like Crohn’s disease.
Due to its restrictive nature, you should be closely monitored by your healthcare provider when on a full liquid diet for more than a few days.
A Full Liquid Diet Menu
You’ll have your choice of beverages on a full liquid diet. With the right tools, you can also make many solid foods diet-friendly. Melting, thinning, straining, or puréeing fruits, vegetables, cheese, and even meat can help you consume a variety of foods.
The following compliant foods are allowed on a full liquid diet. Non-compliant foods are not allowed because they are solid or their textures are too thick and lumpy.
Remember: When setting your menu for the day, you’ll need to take care to choose items that are both allowed on a full liquid diet and that offer you adequate nutrition.
- Fruit and vegetable juice (no pulp)
- Soft drinks
- Sports drinks, electrolyte-replacement drinks
- Coffee, tea
- Milk or dairy-free milk alternatives (soy, almond)
- Milkshakes, malts, smoothies
- Clear or creamed soups (thinned, strained, no solids)
- Honey, syrup, sugar
- Gelatin, pudding, custard
- Ice pops, ice cream, frozen yogurt, sorbet (no nuts, candy, solid toppings/coatings)
- Yogurt (regular or Greek; no granola, seeds, fruit chunks)
- Melted cheese
- Powdered protein, dry milk, other nutritional supplements
- Liquid dietary supplements (Ensure, Glucerna, Boost)
- Meat (unless puréed, thinned, and strained)
- Tofu, meat substitutes
- Nuts and seeds
- Raw fruits and vegetables
- Solid cheese
- Soft or mashed food (e.g., potatoes)
- Soups or stews with noodles, meat, or vegetables
- Whole pasta or rice
- Cereals, granola, oats
- Potato chips, crackers, pretzels, popcorn
- Muffins, cakes, cookies, pastries
- Hard or chewy candy
- All other solid foods unless specifically approved by your healthcare provider
Juices: Fruit and vegetable juice is allowed on a full liquid diet as long as it has been strained to remove any solids, like pulp. You may need to avoid any high-fiber juice such as prune juice altogether. Making your own juice with a high-speed blender or juicer allows you to control the thickness. Or, pour the juice through a mesh sieve or tea strainer to remove residue.
Vegetables: Mashed potatoes and other types of vegetable mash are generally not approved but can be if they are sufficiently thinned. You can blend them with butter, gravy, or sauces, season to taste, and thin with water or broth. They should be no thicker than a smoothie when you’re done.
Grains: Cooked cereals can be thinned with water or milk, then strained. Farina and rice cereal are also easy to thin this way. If you’re trying to add nutrition, prepare your cereal with whole milk or creamer instead of water or skim milk.
Milk: Milk or lactose-free alternatives are approved. Drink your favorite by the glass and/or add it to smoothies and shakes for extra nutrition. Powdered milk can be added to cereals, soups, and eggs to boost protein.
Yogurt and cottage cheese: 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.
Butter: 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. Mix meat with potato flakes and milk before or after cooking to give it the right consistency for a liquid diet.
Nut butter: Nut butter is a good source of healthy fats and protein that can be easily added to shakes or smoothies.
Eggs: Eggs, egg whites, or egg substitutes 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 with milk. If you need to add calories, try topping ice cream, pudding, malts, or milkshakes with fruit that is thoroughly blended with whipped cream.
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 also approved as long as they do not contain solid pieces such as chocolate flakes or mulling spices.