Gastroparesis presents a significant clinical challenge due to delayed gastric emptying, often without mechanical obstruction, causing symptoms impacting patients’ quality of life. Current therapies for gastroparesis include smaller, low-fat, and low-fiber meals, aiming to alleviate symptoms while ensuring adequate nutrition. These conventional methods have limitations, driving the exploration of innovative and less restrictive dietary approaches. Recent research suggests that modifying dietary consistency to a smaller particle size with blended, mashed, minced, and chopped foods can improve gastric emptying and symptom relief. Investigational foods like soy germ pasta, Pistacia atlantica kurdica gum, and modified consistency test diets show promise in enhancing gastric function. Dietary interventions remain pivotal in management, with emerging evidence favoring small particle size diets. A multidisciplinary team is also essential to provide tailored nutrition guidance and address nutrient deficiencies, while screening for eating disorders to optimize patient outcomes.
Introduction
Gastroparesis (GP) is the slowing of the stomach’s ability to empty food contents in the absence of mechanical obstruction. It is a diagnosis encountered and treated across many subspecialities of medicine, including gastroenterology, endocrinology, and primary care. The etiology of GP in 90% of patients is from an idiopathic, diabetic, or postsurgical source.1 Common symptoms of GP include nausea, vomiting, postprandial bloating, and early fullness. The severity of symptoms vary from person to person. The gold standard for diagnosis of GP is gastric scintigraphy using radiolabeled solid food (as the gastric emptying rate of solids and liquids differ).1 Furthermore, there are a few directed medical therapies with supportive evidence available.2
GP has a significant burden of disease, with an estimated increased healthcare cost of 1,026% from 1997 to 2013.3 The increase is indicative of the rising number of hospital admissions and the increasing costs associated with treatment. Current limited treatment options include pharmacologic therapies with prokinetics and antiemetics, surgical/endoscopic treatments such as pyloromyotomy and pyloric botulinum toxin injection, implantable devices to provide gastric electrical stimulation, dietary interventions, and a wide array of alternative approaches ranging from acupuncture to herbal therapies.4-6 Diet interventions remain the first line of treatment, supported by the American College of Gastroenterology (ACG) guidelines.6
Understanding the principles of dietary guidelines for GP can be a helpful tool in the management of adult patients with this diagnosis, especially in settings where referral to a registered dietitian (RD) is either unavailable or impractical. This review aims to offer an overview of the current evidence to support dietary approaches for the management of GP, updates and applications of the small particle size diet, and additional data for investigational foods.
Current Role of Diet in Gastroparesis
The diet management of GP aims to not only alleviate symptoms, but also to address fluid and electrolyte imbalances, and other potential nutrient deficiencies.7 Malnutrition and dehydration are common in patients with moderate to severe gastroparesis as they often consume diets that are not nutrient rich. Also, given that food intake can be a significant symptom trigger for patients, some may inadvertently restrict their caloric intake by consuming smaller portions, heightening the risk for malnutrition. For example, one study found that 64% of patients with either diabetic or idiopathic gastroparesis consumed less than 60% of their daily energy requirement.8 Common deficiencies include iron, vitamin B12, vitamin D, and calcium.9 Another study compared healthy controls to those with GP and found a number of micronutrient deficiencies (such as folate, niacin, riboflavin, thiamine, calcium, copper) in addition to consuming less calories in those with GP.10 Therefore, the goal of diet therapy is to identify nutrient-dense food options that can aid in alleviating a patient’s symptoms without compromising adequate nutrition. Tolerance can vary from person to person.
In diabetic gastroparesis, diet can help achieve glycemic control that is crucial for improving gastric emptying. Not only should their diet help them achieve better overall glycemic control, but also avoid acute hyperglycemia. For example, foods with a higher glycemic index can contribute to post-prandial hyperglycemia that disrupts the emptying of both solid and liquid foods.11
As previously noted by Parrish and McCray in 2011, the traditional dietary approach for GP involves consuming smaller meals that are lower in both fat and fiber.9,12 This is corroborated by recent systematic reviews,13,14 that showed lower fat foods decrease symptoms of GP and another study that showed higher fat content has the opposite effect.15 The same is true for low-fiber diets which might also decrease GP-like symptoms in other disease processes.13 Small meals can also generally reduce the sensation of fullness and thus alleviate GP symptoms.16
If patients are unable to tolerate small solid meals, they may need to use oral nutrition supplements (ONS).17 These are especially useful as liquids empty faster than solids.17 Though there is no direct evidence supporting their use, dietitians and other clinicians alike have found them to be a helpful option to support nutrition in the patient with severe gastroparesis. If a patient cannot tolerate solids, nor ONS, and there is significant concern for ongoing weight loss and malnutrition, enteral nutrition may be needed. Typically, this is given either through a gastrojejunostomy tube (PEG-J), or direct jejunostomy tube to bypass the stomach. Dietitians can assist in selecting the type of enteral formula used (standard, semi-elemental or elemental) and in developing a regimen.17 Enteral formulas containing fiber are usually not recommended due to potential risk of worsening symptoms. Further, if a patient is not able to tolerate enteral nutrition to any extent, or there is some other contraindication to using enteral nutrition, parenteral nutrition may be necessary. Consumption of foods and beverages should continue as tolerated.
The Small Particle Size Diet
In more recent years, the focus of diet for GP has shifted to smaller meal size and modified consistency for smaller particle size, which includes foods that can easily be broken down through blending, grinding, mashing, mincing, and chopping to optimize tolerance (see Table 1).
Small Particle Foods |
Cooking methods: mashed, puree, pate, timbale, sauces, ground, minced, lean cooking methods – limit added fats – baked, broiled, boiled, steamed Fruits/vegetables: mashed turnips, mixed beetroot, pickled beets, asparagus tips, green pea puree, corn pate (cooked and mixed), bean pate (cooked and mixed), Brussels sprout pate (cooked and mixed), mushroom paste, fine mixed onion, dried powdered onion, tomato paste, mashed avocado, puree of fruit or berry, ripe pears without skin, canned peaches, gooseberries, mixed: blueberries, currants, lingonberries, yellow-brown banana, kiwi, watermelon, flour of fruits or almonds Starches: mashed potatoes, pressed potatoes, creamed potatoes, brown crisp, rye crisp Protein/cheeses: mashed-boiled eggs, French omelet, baked omelet Swedish style, baked egg, mixed minced or ground dishes including beef, chicken, turkey, baked flatfish, boiled fish loaf dishes, fish pudding, fish souffle, fish balls, fish pate, fish gratin, herring terrine, mixed shrimp, crab, clams, cottage cheese, Greek yogurt, ricotta cheese, spreadable cheese |
Medium Particle Foods |
Cooking methods: boiled, steamed, roasted, baked Fruits/vegetables: cooked carrots, cooked turnips, cooked parsnips, cooked cauliflower, broccoli flower, mushrooms, mixed leeks, canned crushed tomatoes, pepper without skin, cooked and canned fruit or berry, ripe pears without skin, raspberries, strawberries, yellow banana, kiwi, mango, papaya Starches: boiled potatoes, baked potatoes, whole grain cereal, bread baked on coarse flour Protein/cheeses: scrambled eggs, cooked, canned, roasted, baked meat (beef, turkey, chicken) dishes, jellied veal, extra thin slices of ham, baked salmon, baked mackerel, baked cod fish |
Large Particle Foods |
Cooking methods: raw, wok, fried in a pan, deep fried, coating with egg and breadcrumbs, high fat cooking methods Vegetables: raw carrots, raw turnips, raw parsnips, cooked cauliflower and broccoli stems, asparagus stalk, green pea, boiled corn, cooked beans, cooked Brussels sprouts, raw and cooked cabbage, raw, boiled and fried onion, cooked leeks, rhubarb, salad, cucumber and tomatoes, pepper with skin, and avocado Fruit: fresh fruit, skin and membrane of citrus: orange, clementine, grapefruit, pineapple, blueberries, currants, lingonberries, blackberry, cloudberries, green and green-yellow banana, netted melon Starches: fried potatoes, French potatoes, rice, pasta, parboiled rice and brown rice, non-parboiled rice, bulgur, couscous, porridge, bread, pancakes, white fresh bread, bread with seeds, whole grains Protein/cheeses: high fat cheese, ripened cheese, hard-boiled eggs, soft-boiled eggs, whole meat, cured and smoked salmon, raw spiced salmon, shrimp, crab, clams, tails |
The ACG guidelines now formally recommend small particle size diets, supported by the findings of two main studies.6,18,19 The initial study to support the use of this diet investigated gastric emptying time and postprandial blood glucose levels in patients with Type 1 diabetes mellitus (T1DM) and GP compared to healthy controls. The subjects consumed meals of the same nutrient composition, but with varying particle sizes – one with large particles, and another with small particles.18 Both meals contained identical macronutrient profiles, each providing 375 kcal, 26g protein, 13g fat (25-30% of total energy intake), 38g carbohydrates, and 4.8g fiber. The meal components included 100g of meat, 40g of pasta, 150g of carrots, and 5g of oil. The diet in large particle size consisted of slices of roast beef, pasta boiled for 14 minutes, raw carrots, and canola oil. In contrast, the diet in small particle size included minced and baked beef, pasta, and carrots boiled and mixed in a food processor, along with canola oil.18 For patients with GP, the small particle size meal significantly accelerated gastric emptying compared to the large particle meal. Additionally, the study suggested that small particle size could contribute to improved glycemic control for diabetic patients.18
The second study, a randomized control trial, compared the effects of dietitian-directed meals of small particle size compared to a standard diabetic diet on gastric emptying. Secondary outcomes included the effects of diet on body weight, nutritional intake, metabolic control, mental health, and quality of life. Three different diets were included in the study: one group received a reduced particle size meal (food already processed into small particles), another group received foods that can be easily broken down into small particles (but not pre-prepared for them), and a control group received a diabetic diet that contained normal-sized particles. For all 3 diets, the recommended fat content was 25-30% of total energy, and fiber content was 15g/1000 kcal with 3 meals and 3 snacks or 4-6 small meals per day based on tolerance. Foods that could easily be broken down into small particles were defined as “food [that] should be [easily]…mashed with a fork into small particle size, e.g. mealy potatoes.”19 Therefore, this diet excluded foods with the following characteristics: foods with husks/peels (e.g. corn, peas), membranes (e.g. orange, lemons), stringy foods (e.g. rhubarb, asparagus, leeks, stalks of broccoli), seeds and grains (e.g. nuts and almonds, bread with whole grains), compact, poorly digestible particles (such as pasta, rice) and white fresh bread.19 The control diabetic group used large particle size foods such as whole meat, seafood, cheese slices, almonds and nuts and low glycemic index pasta, rice, grated vegetables, raw vegetable salad, wok vegetables, fresh fruit and bread with whole grain and/or sourdough.19 The results of this study support that smaller particle size diets improve gastric emptying as well as symptoms. The emptying percent at 120 minutes was improved compared to control, as were symptoms such as nausea/vomiting, postprandial fullness, bloating, lower abdominal pain, and heartburn. Also, after 20 weeks on the diet, nutrient intake and glycemic controls stayed the same compared with a typical DM diet.19 This study was limited in that it did not include patients that have other types of GP (such as idiopathic).19
The modified consistency test diet (MD) (which also refers to foods that are chopped, ground, or pureed), is similar to the principles of the small particle size diet. Research has shown that the MD, combined with rapid-acting insulin, can lead to better postprandial glycemic control and thus even more beneficial to those with diabetic GP. 19 In 2022, in a study by Betônico et al., a MD meal was compared to a consistency standard meal which included: rice, beans, grilled chicken, tomato, cooked carrot, and an apple.20 The MD meal consisted of pasty rice, only bean broth, shredded chicken with tomato sauce, overcooked-mashed carrot, and apple puree. The two meals were similar regarding caloric value and macronutrients distribution, approximately 465.14 kcal, 26% lipids (13.9g), 24% protein (28.1g) and 50% carbohydrate (58.3g).20 Results of the study showed that those on the MD had a smaller increase in post-prandial (2 hours after eating) glucose levels. Patients on this diet also had a lower symptom score and complained less of symptoms such as “not able to finish meal” or “stomach or belly feels larger.”20 Similar to the studies supporting the small particle size diets, this was also limited in that it only included those with diabetic gastroparesis.
Updates on Investigational Foods
Soy Germ Pasta
One method that has been explored to expand the dietary options for patients with Type 2 diabetes and gastroparesis is the inclusion of soy germ pasta alongside a diabetic diet. Soy germ is noted for its isoflavones, which have a pro-motility effect on the stomach.21 Unlike conventional pasta, including soybean pasta, only soy germ pasta contains these beneficial isoflavones. In one study, soy germ pasta (containing 2% soy germ and delivering 31–33mg of isoflavones per serving) was tested to liberalize the gastroparesis diet for patients with Type 2 diabetes.21 Patients were randomized into two groups; one group consumed one serving per day of soy germ–enriched pasta (80g) followed by conventional pasta for 8 weeks, while the other group consumed these pastas in reverse sequence.21 The soy germ-enriched pasta contained 33mg of total isoflavones per serving (80g). Compared to conventional pasta, soy germ pasta significantly increased gastric emptying time (i.e., it improved gastric emptying). Glucose and insulin concentrations were not affected by soy germ pasta.21 These findings suggest that soy germ pasta may offer a simple dietary approach for managing Type 2 diabetes. However, soy germ pasta is currently unavailable for purchase. Other high-isoflavone options, equivalent to 33 grams of isoflavones per serving, include foods such as tofu, tempeh, soy protein and soy flour. These alternatives have not been studied in the same context but offer similar isoflavone content22 and, since this was a small pilot study, more data is needed before confidently recommending this option to improve gastroparesis symptoms.
Pistacia atlantica kurdica Gum
Pistacia atlantica is a species of pistachio tree which contains resin, used as chewing gum. The essential oil of this species is said to have pro-motility effects on the stomach.23 To test its effectiveness on symptoms of GP, a study investigated the daily consumption of Pistacia atlantica kurdica chewing gum for one month in patients with diabetic gastroparesis.23 The intervention group chewed 2-grams of Pistacia atlantica kurdica gum twice daily and a placebo group chewed sugar free gum containing industrial plastic polymers twice a day. At the conclusion of the study, the intervention group experienced significant reductions in symptoms, including nausea/vomiting, postprandial fullness/early satiety, and bloating, versus placebo. The experimental group also saw significant decreases in systolic blood pressure and HbA1c.23 This study provides valuable insights into the potential benefits of Pistacia atlantica kurdica gum for managing GP in patients with diabetes, although the gum is also not available for purchase.
Risk of Eating Disorders with Gastroparesis
Patients with GP often discover or adopt restrictive diets to manage their symptoms and may be vulnerable to developing or exacerbating an underlying eating disorder. One study indicated that a GP diagnosis typically precedes the onset of avoidant/restrictive behaviors.10 Another study of patients referred for symptoms indicative of GP revealed that 55% of these patients exhibited signs of a feeding and eating disorder known as Avoidant/Restrictive Food Intake Disorder (ARFID). ARFID is characterized by feeding and eating disturbances that result in failure to meet nutritional needs leading to low weight, nutritional deficiency, dependence on supplemental feedings, and/or psychosocial impairment.24 Common symptoms of ARFID include restricted range and amount of food, avoidance of certain food textures, fears of choking or vomiting, lack of interest in food, as well as gastrointestinal symptoms at mealtimes including early satiety, constipation, abdominal pain, stomach cramps, or an upset stomach related to food consumption.25 These studies support the notion that individuals with GP are at risk of developing eating disorders.12,24 Therefore, it is crucial to take this into consideration when working with patients diagnosed with GP. Screening can be performed with a quick, validated questionnaire such as the Nine Item Avoidant/Restrictive Food Intake Disorder Screen (NIAS).26
• Comprehensive nutritional assessment (patient history, anthropometrics, physical examination focused on nutrition, laboratory tests and diagnostic procedure, food and nutrition history, functional status) • Identifying and preventing patients at risk of malnutrition • Ability to address nutritional deficiencies and promote optimal nutritional status • Restoration of fluids and electrolytes • Provide nutrition counseling and individualized diet recommendations • Recommend nutrition support via oral nutrition supplements, post-pyloric feeding tube or parenteral route • Improve glycemic control in diabetic gastroparesis • Screen for eating disorders – Avoidant/Restrictive Food Intake Disorder • Addressing patients’ individual and mental well-being and quality of life GI Dietitian Database Websites: International Foundation for Gastrointestinal Disorders (IFFGD) iffgd.org American Gastroenterological Association (AGA) gastro.org |
Indications to Refer Patients to a GI Registered Dietitian
The Role of the Registered Dietitian
The RD plays an important part in the treatment and management of GI disorders, including GP. Dietitians are integral members of a multidisciplinary team and are uniquely qualified in the assessment and management of nutritional status. They are skilled at identifying patients at risk of and with confirmed malnutrition. Patients with GP should be referred to a RD for a comprehensive nutrition assessment to assess the patient’s nutritional status and formulate a personalized nutrition intervention plan.17 The nutrition plan may encompass educating the patient about gastroparesis-specific nutrition, providing counseling for effective implementation, and adjusting dietary strategies to address any emerging challenges.17 In patients with diabetic gastroparesis in particular, research has shown that incorporating nutrition intervention by a RD can lead to improved glycemic control, reduced risk of complications, and improved quality of life.27 When available, it can be important to recognize when it can be important to refer someone to a RD for further recommendations and management in their disease course (see Table 2).
Conclusion
Nutritional strategies for managing GP encompass practices of consuming smaller, more frequent meals, while limiting foods high in fiber and fats (see Table 3). Dietary approaches for people with GP aim to mitigate symptoms and improve digestion while ensuring caloric goals are met and micronutrient deficiencies are prevented. Specific dietary interventions hold the potential to ameliorate symptoms and enhance gastric emptying in adult patients, with diets of small particle size being a prime example. This approach, which includes foods in a consistency of blended, mashed, minced, and chopped, has demonstrated a significant reduction in the severity of symptoms of GP such as nausea/vomiting, postprandial fullness, and bloating. Optimizing nutrition is a multidisciplinary approach for patients with GP and should also include considering screening for eating disorders. More research is needed regarding the use of investigational foods in treatment for GP.
Consider a GP diet that alters meal – volume, consistency, composition, amount of fat, and fiber |
Foods in small particle size through small meals throughout the day Fat content (25–30% of total energy)16 Fiber content (15g/1000kcal)16 4-6 small meals per day based on tolerance Limit foods of large particle size Liquid meals and/or high energy/protein oral nutritional supplement (ONS) if appropriate Modify meal timing, form of carbohydrates (simple, complex), according to diabetes treatment regimen Diet must be personalized as tolerance can vary from person to person depending on severity of symptoms. |
Summary of Diet Recommendations for Gastroparesis
References
1. Rao SSC, Camilleri M, Hasler WL, et al. Evaluation of gastrointestinal transit in clinical practice: position paper of the American and European Neurogastroenterology and Motility Societies. Neurogastroenterology & Motility. 2011;23(1):8-23.
2. Bonetto S, Gruden G, Beccuti G, Ferro A, Saracco GM, Pellicano R. Management of dyspepsia and gastroparesis in patients with diabetes. a clinical point of view in the year 2021. Journal of Clinical Medicine. 2021;10(6):1313.
3. Wadhwa V, Mehta D, Jobanputra Y, Lopez R, Thota PN, Sanaka MR. Healthcare utilization and costs associated with gastroparesis. World Journal of Gastroenterology. 2017;23(24):4428.
4. Gupta E, Lee LA. Diet and complementary medicine for chronic unexplained nausea and vomiting and gastroparesis. Current treatment options in gastroenterology. 2016;14:401-409.
5. Parkman HP, Hasler WL, Fisher RS. American Gastroenterological Association technical review on the diagnosis and treatment of gastroparesis. Gastroenterology. 2004;127(5):1592-1622.
6. Camilleri M, Kuo B, Nguyen L, et al. ACG Clinical Guideline: Gastroparesis. The American Journal of Gastroenterology. 2022;117(8):1197-1220.
7. Aguilar A, Malagelada C, Serra J. Nutritional challenges in patients with gastroparesis. Current Opinion in Clinical Nutrition & Metabolic Care. 2022;25(5):360-363.
8. Parkman HP, Yates KP, Hasler WL, et al. Dietary intake and nutritional deficiencies in patients with diabetic or idiopathic gastroparesis. Gastroenterology. 2011;141(2):486-498. e7.
9. Parrish CR, McCray S. Gastroparesis and nutrition: The art. Pract Gastroenterol. 2011;99(4):26-41.
10. Ogorek CP, Davidson L, Fisher RS, Krevsky B. Idiopathic gastroparesis is associated with a multiplicity of severe dietary deficiencies. American Journal of Gastroenterology (Springer Nature). 1991;86(4)
11. Halland M, Bharucha AE. Relationship between control of glycemia and gastric emptying disturbances in diabetes mellitus. Clinical Gastroenterology and Hepatology. 2016;14(7):929-936.
12. Wytiaz V, Homko C, Duffy F, Schey R, Parkman HP. Foods provoking and alleviating symptoms in gastroparesis: patient experiences. Digestive Diseases and Sciences. 2015;60:1052-1058.
13. Lehmann S, Ferrie S, Carey S. Nutrition management in patients with chronic gastrointestinal motility disorders: a systematic literature review. Nutrition in Clinical Practice. 2020;35(2):219-230.
14. Eseonu D, Su T, Lee K, Chumpitazi BP, Shulman RJ, Hernaez R. Dietary interventions for gastroparesis: a systematic review. Advances in Nutrition. 2022;13(5):1715-1724.
15. Homko C, Duffy F, Friedenberg F, Boden G, Parkman H. Effect of dietary fat and food consistency on gastroparesis symptoms in patients with gastroparesis. Neurogastroenterology & Motility. 2015;27(4):501-508.
16. Barrett AC, Johnson KP, Halabi ME, Parkman HP. Meal-eating characteristics among patients with symptoms of gastroparesis: Relationships to delays in gastric emptying. Neurogastroenterology & Motility. 2023;35(11):e14661.
17. Limketkai BN, LeBrett W, Lin L, Shah ND. Nutritional approaches for gastroparesis. The Lancet Gastroenterology & Hepatology. 2020;5(11):1017-1026.
18. Olausson EA, Alpsten M, Larsson A, Mattsson H, Andersson H, Attvall S. Small particle size of a solid meal increases gastric emptying and late postprandial glycaemic response in diabetic subjects with gastroparesis. Diabetes Research and Clinical Practice. 2008;80(2):231-237.
19. Olausson EA, Störsrud S, Grundin H, Isaksson M, Attvall S, Simrén M. A small particle size diet reduces upper gastrointestinal symptoms in patients with diabetic gastroparesis: a randomized controlled trial. Official Journal of the American College of Gastroenterology| ACG. 2014;109(3):375-385.
20. Betônico CC, Cobello AV, Santos-Bezerra DP, et al. Diet consistency modification improves postprandial glycemic and gastroparesis symptoms. Journal of Diabetes & Metabolic Disorders. 2022;21(2):1661-1667.
21. Setchell KD, Nardi E, Battezzati P-M, et al. Novel soy germ pasta enriched in isoflavones ameliorates gastroparesis in type 2 diabetes: a pilot study. Diabetes Care. 2013;36(11):3495-3497.
22. Messina M, Nagata C, Wu AH. Estimated Asian adult soy protein and isoflavone intakes. Nutrition and Cancer. 2006;55(1):1-12.
23. Mahjoub F, Salari R, Yousefi M, Mohebbi M, Saki A, Rezayat KA. Effect of Pistacia atlantica kurdica gum on diabetic gastroparesis symptoms: a randomized, triple-blind placebo-controlled clinical trial. Electronic Physician. 2018;10(7):6997.
24. Murray HB, Bailey AP, Keshishian AC, et al. Prevalence and characteristics of avoidant/restrictive food intake disorder in adult neurogastroenterology patients. Clinical Gastroenterology and Hepatology. 2020;18(9):1995-2002. e1.
25. Ridgeway L, McNicholas F. Clinical management of avoidant restrictive food intake disorder (ARFID). Irish Medical Journal. 2021;114(4):331.
26. Zickgraf HF, Ellis JM. Initial validation of the Nine Item Avoidant/Restrictive Food Intake disorder screen (NIAS): A measure of three restrictive eating patterns. Appetite. 2018;123:32-42.
27. Moore M, Evert AB, Evert AB, Franz MJ. Nutrition Therapy for Diabetic Gastroparesis. American Diabetes Association Guide to Nutrition Therapy for Diabetes. American Diabetes Association; 2017:0.