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Full Liquid Diet
Definition/Introduction
Patients not ready for a regular diet due to elective or emergent procedures or who experience irregularity in gastrointestinal function, dysphagia, a transition from prolonged fasted periods, etc., are typically placed on a restrictive diet.[1][2][3] Dietary restrictions can be as restrictive as no food or liquids allowed by mouth, which may increase in a stepwise fashion until reaching regular nutrition. One step in that progression is a full liquid diet. A patient prescribed a full liquid diet follows a specific diet type requiring all liquids and semi-liquids but no forms of solid intake. Unlike a clear liquid diet, which includes only liquids and semi-liquids that are non-opaque, a full liquid diet is more inclusive, as it allows all types of liquids.[4]
Issues of Concern
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Issues of Concern
The use of any modified diet, including a full liquid diet, can be a potential issue for patients if used long-term. For example, in patients with oropharyngeal dysphagia, this type of modified diet can lead to poor nutrition. The use of modified diets, including full thickened liquid diets in long-term care patients, has correlations with higher BUN and creatinine levels as well as higher rates of dehydration over time. The use of certain types of full liquid diets can also affect drug absorption. Studies have shown that using full thickened liquid diets to take medications can affect the rate of absorption by delaying drug dissolution. Finally, full liquid diets can affect a patient's quality of life over time due to patient dissatisfaction with taste when supplemented with nutrients, patient discomfort with the texture of diet lacking solid food, and increased thirst depending on what full liquids the patient receives.[5]
Clinical Significance
Even with the concerns associated with modified diets due to poor nutrition, full liquid diets have historically been more likely than clear liquid diets to be supplemented with commercial formulas that provide a higher caloric intake for patients.[6] This difference can be as drastic as a less than 1000 kilocalorie daily intake in patients on clear liquid diets that are not supplemented with commercial formulas to greater than 15000 kilocalories intake for patients on a full liquid diet supplemented with commercial formulas.[6] This state is clinically significant due to the potential of a full liquid diet to be more efficacious in patients on dietary restriction who require a higher caloric intake. Full liquid diets are also potentially beneficial for patients suffering from dysphagia, as the texture and consistency provide less risk of penetration-aspiration; however, more research is necessary to fully understand the role of full liquid diets relative to swallowing physiology.[7]
Nursing, Allied Health, and Interprofessional Team Interventions
The main indication for a full liquid diet is in the perioperative period.[8] This refers to the period around the time of the operation, including pre- and post-operative management. Other more restrictive diets can be used during this time as well. Still, one added benefit of a full liquid diet is the higher amount of calories and added amount of nutrients provided, which has links to fewer post-operative complications.[8] This situation especially becomes an issue of importance for patients receiving surgery on any part of the gastrointestinal tract, who is in any way immunosuppressed, such as a cancer patient. Bozzetti et al. showed that the most significant postoperative complications in patients with gastric cancer included weight loss, advanced age, earlier surgery involving the pancreas, and lower serum albumin. Increasing amounts of nutritional support reduced postoperative complications. The best form of nutritional support for those patients was immune-enhanced, but results showed an increased protective effect against complications with increased nutritional support.[9] Although more research is needed to confirm the implication, this and other studies imply the added benefit of a full liquid diet compared to its more restrictive counterparts in preventing malnutrition in even non-immunosuppressed patients.[9][10] In abdominal surgeries for patients regardless of their immunosuppressive state, the typical dietary progression post-operatively begins with a clear liquid diet while recovering from anesthesia, followed by the full liquid diet, then a soft diet, and finally, regular dietary intake.[11]
References
Leszczynski AM, MacArthur KL, Nelson KP, Schueler SA, Quatromoni PA, Jacobson BC. The association among diet, dietary fiber, and bowel preparation at colonoscopy. Gastrointestinal endoscopy. 2018 Oct:88(4):685-694. doi: 10.1016/j.gie.2018.06.034. Epub 2018 Jul 6 [PubMed PMID: 30220301]
Saltzman AF, Warncke JC, Colvin AN, Carrasco A Jr, Roach JP, Bruny JL, Cost NG. Development of a postoperative care pathway for children with renal tumors. Journal of pediatric urology. 2018 Aug:14(4):326.e1-326.e6. doi: 10.1016/j.jpurol.2018.05.002. Epub 2018 May 31 [PubMed PMID: 29891188]
Lucchesi FA, Gadelha PCFP. Nutritional status and evaluation of the perioperative fasting time among patients submitted to elective and emergency surgeries at a reference hospital. Revista do Colegio Brasileiro de Cirurgioes. 2019:46(4):e20192222. doi: 10.1590/0100-6991e-20192222. Epub 2019 Oct 17 [PubMed PMID: 31644720]
Oates JR, Sharma S. Clear Liquid Diet. StatPearls. 2022 Jan:(): [PubMed PMID: 30860735]
O'Keeffe ST. Use of modified diets to prevent aspiration in oropharyngeal dysphagia: is current practice justified? BMC geriatrics. 2018 Jul 20:18(1):167. doi: 10.1186/s12877-018-0839-7. Epub 2018 Jul 20 [PubMed PMID: 30029632]
Murray DP, Welsh JD, Rankin RA, Warner R. Survey: use of clear and full liquid diets with or without commercially produced formulas. JPEN. Journal of parenteral and enteral nutrition. 1985 Nov-Dec:9(6):732-4 [PubMed PMID: 4068196]
Level 3 (low-level) evidenceSteele CM, Alsanei WA, Ayanikalath S, Barbon CE, Chen J, Cichero JA, Coutts K, Dantas RO, Duivestein J, Giosa L, Hanson B, Lam P, Lecko C, Leigh C, Nagy A, Namasivayam AM, Nascimento WV, Odendaal I, Smith CH, Wang H. The influence of food texture and liquid consistency modification on swallowing physiology and function: a systematic review. Dysphagia. 2015 Feb:30(1):2-26. doi: 10.1007/s00455-014-9578-x. Epub 2014 Oct 25 [PubMed PMID: 25343878]
Level 1 (high-level) evidenceToulson Davisson Correia MI, Costa Fonseca P, Machado Cruz GA. Perioperative nutritional management of patients undergoing laparotomy. Nutricion hospitalaria. 2009 Jul-Aug:24(4):479-84 [PubMed PMID: 19721929]
Bozzetti F, Gianotti L, Braga M, Di Carlo V, Mariani L. Postoperative complications in gastrointestinal cancer patients: the joint role of the nutritional status and the nutritional support. Clinical nutrition (Edinburgh, Scotland). 2007 Dec:26(6):698-709 [PubMed PMID: 17683831]
Koretz RL, Lipman TO, Klein S, American Gastroenterological Association. AGA technical review on parenteral nutrition. Gastroenterology. 2001 Oct:121(4):970-1001 [PubMed PMID: 11606512]
Kim HO, Kang M, Lee SR, Jung KU, Kim H, Chun HK. Patient-Controlled Nutrition After Abdominal Surgery: Novel Concept Contrary to Surgical Dogma. Annals of coloproctology. 2018 Oct:34(5):253-258. doi: 10.3393/ac.2018.05.29. Epub 2018 Oct 31 [PubMed PMID: 30419723]