Clear liquids (those you can see through) are usually prescribed prior to a medical test or following a medical procedure. Though the diet is primarily used in health care settings, it's often used as a home remedy to alleviate nausea and vomiting as well. Long-term use of this highly restrictive diet is not recommended.
Function
Clear liquids are easily digested and absorbed, providing a period of rest for the gastrointestinal (GI) tract. Liquids help quench thirst and maintain adequate hydration. The diet also helps rid the bowels of residues that can interfere with visibility in some medical procedures.
Indication
This diet is frequently prescribed prior to medical tests, such as a colonoscopy or biopsy; and it's commonly used following surgery to minimize gastric stimulation while the digestive system is still sluggish and recovering. The typical order of diet advancement after surgery is clear liquids, full liquids, soft, and finally a regular diet--if the others are tolerated well.
Nutritional Adequacy
Clear liquids are not sufficient to meet basic nutritional needs. Most are primarily carbohydrate sources and contain little to no protein or fat. For example, a 4-oz. glass of apple juice contains about 60 calories, 15 grams of carbohydrate, 0 grams of protein and 0 grams of fat. It would take 33 glasses just to reach 2,000 calories. Some clear liquid supplements are fortified with protein and other nutrients, but not in the amounts necessary to sustain life over an extended period of time.
Caution
Because clear liquid diets lack key nutrients, they should be used only for short periods of time--typically 24 to 36 hours. If clear liquids are anticipated for longer durations, then IV feedings are often considered. A registered dietitian can assist the health care team with determining whether an alternative form of nutrition is necessary.
Acceptable Liquids
Liquids that are considered clear include water, ice, coffee without cream, tea, clear soda (such as ginger ale and lemon-lime), cranberry juice, grape juice, apple juice, lemonade, gelatin, honey, hard candies, broth-based soups, fruit ice and Popsicles. Some clear nutritional supplements, such as Boost® Breeze or Enlive®, provide additional calories and nutrients. Cream-based soups, ice cream and juices with pulp (such as orange, tomato, and grapefruit) are not allowed.
References
- "Clinical Nutrition and Dietetics"; Frances J. Zeman; 1991
- "Bowes & Church's Food Values of Portions Commonly Consumed"; Jean A. Pennington; 1998
Member Comments