This diet provides adequate water, 500–1000 kcal as simple sugar, and some electrolytes. It is fiber-free and requires minimal digestion or intestinal motility.
A clear liquid diet is useful for patients with resolving postoperative ileus, acute gastroenteritis, partial intestinal obstruction, and in preparation for diagnostic GI procedures. It is commonly used as the first diet for patients who have been taking nothing by mouth for a long period. Because of the low calorie and minimal protein content of the clear liquid diet, it is used only for short durations.
The full liquid diet provides adequate water and can be designed to provide sufficient calories and protein. Vitamins and minerals—especially folic acid, iron, and vitamin B6—may be inadequate and should be provided in the form of supplements. Dairy products, protein shakes, and soups are used to supplement clear liquids. Commercial oral supplements can also be incorporated into the diet or used alone.
This diet is low in residue and can be used in patients with difficulty chewing or swallowing, with partial obstructions, or in preparation for certain diagnostic procedures. Full liquid diets are commonly used following clear liquid diets in patients who have been taking nothing by mouth for a long period.
Soft diets are designed for patients unable to chew or swallow hard food. Easily masticated foods are used, and most raw fruits and vegetables, coarse breads, and cereals are eliminated. Soft diets are commonly used to assist in progression from full liquid diets to regular diets in postoperative patients, patients who are too weak or those whose dentition is too poor for a regular diet, head and neck surgical patients, and patients with esophageal strictures. The soft diet can be designed to meet all nutritional requirements.