Information alert

If you need a large print, audio, braille, easy-read, age-friendly or translated copy of this page, email the patient information team at We will do our best to meet your needs.

Functional dyspepsia and gastroparesis are two interchangeable conditions that often co-exist. The causes of these conditions are complex and not fully understood. However there are good treatment pathways for managing the symptoms associated with these conditions.

Dietary modification is one very important part of the management. Both functional dyspepsia and gastroparesis share the same common gastrointestinal symptoms including; postprandial fullness, early satiety, not being able to finish a normal sized meal, nausea, vomiting, bloating and abdominal pain or burning which originates from the stomach.

Often symptoms are either triggered by eating or symptom severity worsens when eating. This page provides information on how to modify your eating and drinking to better manage your gastrointestinal symptoms and improve your food related quality of life.

Dyspepsia is a medical term describing a collection of symptoms, which is often referred to as indigestion. It is very common and around 10-15% of the general population suffer symptoms of indigestion (dyspepsia). It consists of symptoms such as pain or burning in the upper part of the abdomen (tummy), feeling abnormally full-up early on in a meal, or experiencing a heaviness in the abdomen that may be worse after eating.

These symptoms arise from problems with the 4 stomach or the first part of the small intestine, called the duodenum. Together these are referred to as the upper gut. Sometimes these symptoms can be due to an underlying cause, such as an ulcer. However, in most cases, tests find no abnormality and this condition is referred to as Functional Dyspepsia (FD). FD is diagnosed based on your symptoms, under the Rome IV criteria of a Disorder of Gut Brain Interaction with a global prevalence of 7%.

Importantly, normal test results do not mean that there is no cause for FD. It is caused by issues with the two-way communication between the upper gut and the brain. Problems with the nerves supplying the stomach and duodenum may make them more sensitive to normal function.

Sometimes the stomach may be slower to empty, contributing to feelings of early fullness. Psychological factors, such as stress, certain foods or changes in the micro-organisms (bugs) living in the upper gut may also play a role in triggering symptoms.

Gastroparesis is a digestive syndrome characterized by delayed gastric emptying (GE) in the absence of any obstruction and must include one or more relevant symptoms including: postprandial fullness, early satiety, nausea, vomiting, bloating or abdominal pain. For the majority of cases no underlying cause can be found for the gastroparesis and it is defined as idiopathic (meaning cause unknown).

Other causes of gastroparesis include diabetes, viral infections or following surgery. A gastric emptying (GE) study using magnetic resonance imaging (MRI) will determine any delay in food emptying from your stomach. A delay in GE can be defined based on the retention of food in the stomach over 4 hourly time points Even though a GE study is required to diagnose gastroparesis the actual term ‘gastroparesis’ refers to very severe delays in GE.

Many patients with FD have delayed gastric emptying in which case this is termed Functional Dyspepsia with delayed gastric emptying rather than gastroparesis (very severe delay).

First line advice is ‘generic’ advice that is provided to all patients as the majority will find some benefit. Unfortunately dietary advice will not improve symptoms for everyone.

To improve symptoms a combination of treatments including diet, lifestyle, medication and psychological therapies may need to be implemented.

Use the advice provided here as a template for your diet and adjust the details based on your particular dietary preferences and beliefs.

How food enters the stomach can affect symptoms. If food comes into the stomach too fast or in larger chunks it is more likely to trigger symptoms.

Chew your food ‘well’:

  • Chewing food ‘well’ means chewing it enough to break it down into smaller particle sizes
  • Take "one bite at a time" (smaller bites)
  • Excessive chewing or sucking should be avoided by choosing food that is easily chewed or modifying the texture of food. Otherwise you can increase air being inhaled when eating which may cause more symptoms / discomfort
  • Chewing lots is associated with increased satiety so the more you need to chew a food then potentially the more likely it will provoke symptoms of fullness  
  • Avoid foods that cannot be chewed well e.g. celery, raw vegetables etc. and foods that can require a lot of chewing e.g. certain cuts of meat like beef / steak
  • Remember digestion starts in the mouth!

Eat slowly:

  • Aim for 10-20mins for each meal
  • Eating slowly allows time for air to be moved along the intestine, or absorbed
  • Ways to slow eating speed include putting a small amount of food in your mouth at a time (size of a thumbnail) and chew this ‘well’. Eating at a table without any distractions (no TV) and putting down cutlery between mouthfuls can also help

Eat in a correct position:

  • While eating sit upright on a chair at a table and do not hunch (bend the top of your body forward) over your food
  • Sit upright for 1-2 hours (or more) after eating and do not lie down / slouch soon after having a meal
  • Try going for a light walk e.g. round the garden / streets, after eating to help food empty from your stomach quicker

Do not aim to eat until you are ‘full’:

  • Try not to eat too much at one time as even one extra mouthful more than your stomach can accommodate at one time can trigger symptoms
  • Learn to eat until you are not quite satisfied, knowing that you can eat again relatively soon afterwards

The volume or portion size of food can impact on symptoms and typically larger portion sizes will trigger more severe symptoms. Additionally little and often is better than one or two meals to help spread the overall food intake throughout the day.

Adjust portion size:

  • In general your portion sizes should be reduced however there will be some foods that you can manage larger portion sizes without triggering severe symptoms

Eat regular meals:

  • At minimum consume 3 smaller meals per day (i.e. breakfast, lunch and dinner) with no more than 4-5 hours between meals
  • It may be necessary to have up to 6 small meals per day
  • You should attempt to eat even if you do not feel hungry
  • Avoid only eating one meal per day as this will worsen symptoms

Include snacks between meals:

  • Especially if you are at risk of losing weight or main meals are very small
  • A ‘snack’ could include a wide range of foods, for example, a small bowl of cereal, a nourishing drink, a slice of omelette, fruit, yoghurt, bakery items etc.

Try not to drink too much fluid before or with meals:

  • Fluid may fill you up and you may not manage your meal, and/or the additional fluid in the stomach may trigger symptoms
  • You should not drink >100mls of fluid (half a glass) for 30 minutes before or after eating
  • You can still sip fluid during mealtimes
  • Large volumes (>100mls) of fluid drunk quickly can also trigger symptoms
  • The best way to stay hydrated is to sip throughout the day
  • Excessive sucking e.g. using a straw, should be avoided as this can increase air and trigger symptoms

Be wary of all fizzy drinks:

  • The gas in fizzy drinks will enter your stomach and can cause discomfort and may need to be avoided
  • However for some people fizzy drinks do not trigger symptoms and may relive the feeling of nausea so be guided by your own symptoms

Nourishing drinks can replace water:

  • Milk, juice, smoothies, hot chocolate and any other drinks that contain calories may need to replace other low-calorie drinks and/or water if weight loss is a concern

  • In general softer foods (e.g. fork mashable foods) and liquid forms of foods (e.g. puree soup, smoothies, shakes) will be better tolerated and less likely to trigger severe symptoms
  • Some meals will fall into both categories (e.g. casserole, slow cooked, stews, soups). Meals that contain both soft foods and a liquid element may be better tolerated than puree versions of the same meal. This is because a purred soup compared to a chunky soft soup will be more viscous and may stay in the stomach for longer.
  • If you have moderate to severe symptoms then it is recommended to consistently include 1/3rd of meals daily in a soft or liquid texture. For example a breakfast could be a smoothie, lunch a soft/chunky soup, dinner could be a soft meal e.g. steamed fish with mashed potatoes and soft cooked broccoli. While snacks could include nourishing drink options
  • If symptoms are severe to very severe then 2/3rds or more of the diet everyday may need to be liquid and 1/3rd soft.
  • As symptoms improve food textures can become more normal/solid
  • If symptoms are worse in the evening, then try having more of these modified texture foods for dinner. However some people find having texture modified meals during the day and a ‘normal’ meal in the evening equally as effective

Adapt cooking techniques:

  • Typically raw fruits, raw vegetables, salad and stir-fried food are less well tolerated. You can still have these foods but need to eat them less often rather than daily
  • For example an apple is one of the hardest fruits and so should be limited or avoided. Similarly having a fruit salad with several portions of ‘raw’ fruit is more likely to trigger symptoms than one portion of fruit
  • You can cook fruit and use it as a puree or simply included within a suitable meal or pudding
  • You may find frozen fruit is a useful addition to the diet. The freezing process can degrade the fruits skin and therefore softens
  • Steaming, roasting, using a slow cooker or boiling vegetables to soften them will often be better tolerated than raw / al dente or stir fried.
  •  Although you can eat salad it would be wise to avoid large portions of salad and do not eat salad everyday
  • Slow cooked meats / poultry or minced meats / poultry will be better tolerated than solid chunks of fried meat / poultry

  • Animal protein including poultry (chicken and turkey) and meat (beef, pork and lamb) have been reported as triggering more severe symptoms than other protein-based foods such as eggs and fish. This may be due in part to their solid texture.
  • As mentioned in modify texture of foods; if you find some animal protein-based foods trigger increased symptoms then adapting the texture of these foods via food processing and cooking techniques can often make the foods better tolerated i.e. use a slow cooker or cook for a long time in a soup, stew or casserole. Use minced versions of meat or poultry
  • In addition try consuming more fish, eggs and plant-based protein alternatives e.g. Quorn products, to replace some meat and poultry. There are many good choices of plant-based protein alternative foods and some of these taste the same as the real thing. It is worth trying some different products if you struggle with meat.

Avoid ‘SOLID’ foods high in fat.

High fat is any food with >17.5g of fat per 100g. Fat slows down the speed food empties from the stomach and can mean your stomach feels very full for longer, increasing symptoms:

  • Many high fat foods are also foods with a ‘solid’ texture and the combined effect of high fat plus solid texture could contribute to more severe symptoms
  • High fat foods consumed in a liquid form e.g. ice cream / smoothie can empty from the stomach quicker and do not need to be avoided  
  • We advise having texture modified (soft) high fat products within a soft / liquid meal as this can also help the food empty from the stomach quicker
  • See table below for more detail of foods to avoid/modify
  • Avoid high fat solid foods and modify texture for ~4 weeks
  • You do not need to be on a low fat diet!
High fat foods Avoid / modify options
Deep fried / take away Avoid for ~4 weeks as not essential in diet (e.g. kebab, fish & chips, bhajis/samosa etc.)
Processed meats & some cuts of red meats e.g. burger, sausage Avoid high fat products. Switch to products with lower fat contents e.g. chicken sausages, or buy plant based alternatives e.g. Vegan burger / sausages.
Products made with fat e.g. pastry (pies), chocolate, cakes, crisps Search for similar lower fat products or choose alternative product e.g. crumpet not almond croissant. Check portion guide*
Nuts, seeds and nut / seed butters Avoid whole nuts and seeds. Use ground versions, sticking to 1 tablespoon portion size per soft / liquid mea
Mayonnaise and creamy sauces / coleslaw ‘Light’ mayonnaise is high fat; choose ‘Lighter than light’ Buy/prepare own lower fat versions of sauces. Check portion guide*
Oily fish e.g. mackerel Choose less fatty oily fish / white fish. Tinned less fat than fresh. Have within a soft meal. Check portion guide*
Avocado and olives Not all olive varieties are high fat; choose the non-high fat olives, watch portion size! Have only ½ a soft avocado with a soft /liquid meal.
Cheese. Most cheese is high fat including some reduced fat cheddar cheeses Reduced fat mozzarella and half fat cheddar are suitable. Otherwise stick to 30g portion sizes of cheese. Feta / mozzarella / edam will be lower in fat than cheddar / stilton / brie / parmesan but still high in fat. Have with soft meals


*Check portion guide. In the table where it mentions ‘check portion guide’ this means checking the amount of fat in the product per portion as it may be suitable. For example ¼ of a quiche will not be high fat but is a portion however 1 portion (fillet) of mackerel is high in fat and should be avoided.

Food Labels:

  • You will need to look on nutrition labels for fat content information (>17.5g of fat per 100g)
  • Check labels for total fat / 100g and also per portion as some products can be consumed if the portion size recommended is adhered to
  • Use 1tbsp (or less) of cooking oils, or salad dressings. These can still be included to provide flavour. You can include items which provide flavour such as pesto, curry paste, harissa in cooking, again aiming for 1tbsp or less. Use fresh and dried herbs and spices to provide additional flavour. Avoid deep frying
  • For general information about fat please read the NHS website Fat Facts page here

Modify the texture of foods high in fibre for ~4 weeks.

High fibre is any food with >6g fibre / 100g. These foods may spend longer in your stomach making you feel full but by altering the texture to soft / smaller particle sizes, it will help the food move through the stomach faster

  • It is not known whether it is the amount of fibre (g/100g), or the type of fibre (resistant starch /fructans) found in these foods that trigger upper GI symptoms
  • We therefore advise having high fibre products within a soft / liquid meal e.g. 1- 2tbsps pulses in a soup/ or as hummus
  • And/or modifying the texture (decreasing the particle size) of a high fibre food
  • Some products, such as bread, will have lower fibre options that you can have as an alternative
  • Please note the vast majority of fruits and vegetables are not high in fibre! Therefore you do not need to avoid fruits and vegetables apart from the ones mentioned in the table below
High fibre foods Modifying texture ideas
Cereals (e.g. Bran Flakes, Weetabix etc.) Soak to make soft or blend into a smoothie
Bread products (wholemeal / granary) Dip bread in soups, buy freshly baked bread, stick to maximum 2 slices of bread / day
Oats Oats (see example below)
Pulses and legumes (beans, chick peas, lentils etc.) Portion size 1-2 tablespoons, wash tinned version well. Choose ‘softer’ options i.e. lentils / cannellini beans vs kidney / borlotti beans. Refried beans / hummus already texture modified. Avoid having with other high fibre products (e.g. bread)
Nuts and seeds (nuts and seeds are also high in fat) Avoid whole nuts and seeds. Use ground versions instead, sticking to 1 tablespoon portion size per soft / liquid meal
Popcorn Be aware some popcorn is high fibre (and high fat) therefore choose product after checking the nutrition label
Any fibre taken in a supplemental form Avoid for 4 weeks unless essential for symptoms / constipation e.g. fybogel, psyllium husk


Bread wheat products (additional advice)

  • Bread contains both resistant starch (see section on overlapping bloating and/or distention) and a fibre called a fructan which is highly fermentable and increases gas production which may cause GI symptoms
  • Bread can also form a homogeneous bolus (gloop) in the stomach that takes longer to digest and may trigger upper GI symptoms and/or bloating
  • Therefore bread in any form (gluten free / low fibre etc.) could be an item to reduce in frequency to once per day maximum (up to 2 slices / day) and/or not eaten everyday
  • You do not need to avoid bread! Just moderate intake
  • Take care with meals where wheat can be eaten in larger portions e.g. lasagne and garlic bread, curry with roti and samosa.

Food processing techniques

  • Processing of products (completed by the food industry) can often help with the toleration of food
  • The food processing decreases the particle size of the food helping it to move through the stomach quicker, triggering less severe symptoms
  • Start with the smaller particle size option and increase portion size (e.g. 1 tablespoon at a time). You could also mix different particle size oats together

Food labels

  • You will need to look on nutrition labels for fibre content information (>6g fibre / 100g)
  • Check labels for total fibre / 100g and also per portion as some products can be consumed if you stick to the portion size recommended

  • Eating behaviours – helps to start digestion properly
  • Volume – smaller portions are recommended
  • Frequency – have regular meals; at least 3 per day
  • Texture – soft and liquid foods are a key part of advice and should be included every day in the diet
  • Specific nutrients – in particular avoid solid high fat foods and modify the texture of high fibre foods

If you find the first line dietary advice improves your symptoms then you should continue to follow the advice. Over time as your symptoms are better managed you may be able to modify the dietary advice and therefore will not have to follow the advice so strictly. We provide a 2nd line dietary advice booklet to help with modifying the diet following 1st line advice.


  • Follow ‘Low Risk Drinking Guidelines’ e.g. in the UK 14 units per week spread evenly over 3 or more days is advised. See more here:  

Coffee and caffeine:

  • Reduce coffee to 2-3 shots/cups of coffee per day
  • With other caffeinated drinks it is sensible to restrict all caffeinated drinks to 3 cups per day (this includes coffee).


  • If you regularly consume chilli then avoid foods with large amounts of chilli added and instead opt for ‘mild’ dishes or if using chilli at home use a mild chilli e.g. Jalapeno rather than Scott Bonnet
  • If you only consume chilli occasionally then avoid chilli altogether as only having it occasionally can increase the risk of experiencing symptoms

If you are underweight (BMI ≤18.4kg/m2 ) and/or have lost weight unintentionally and wish to gain weight gain then you may need to include an additional source of calories in your daily diet.

  • Please note that improving symptoms via 1st line dietary advice can help improve overall food intake and therefore this may achieve some desired gain weight

When you have severe upper GI symptoms it can be easier to ‘drink calories’ rather than ‘eat calories’ and therefore you may find the following advice useful:

  • Create a ‘nourishing drink’ and include this in addition to your current dietary intake on a daily basis
  • You could consume your nourishing drink between meals as a ‘snack’ e.g. 2-3x100ml small drinks during the day or if you can tolerate larger volumes then 1-2 nourishing drinks per day
  • Or you could include a nourishing drink as a meal if you previously did not eat a meal
  • For further information see the UCLH nourishing drinks page (search ‘nourishing’ on UCLH website):
  • For more information on nutrition support strategies please follow the links to the UCLH website where you can access the following diet sheets:
    • Soft and bite sized nourishing diet:
    • If you require nutrition support advice suitable for a vegan diet or predominantly plant based diet please see the following diet sheet: A nourishing plant-based diet
  • Remember to modify the advice in these resources to match the 1st line dietary advice in this booklet
  • Additionally the NHS Patient Webinars provide information on managing malnutrition and vegan friendly malnutrition advice

  • First please check that you are following the first line dietary advice as strictly as you can. It might be that you need to be very strict with following all the advice contained in this diet sheet
  • Dietary therapy will not improve symptoms for everybody and this may be the case for you. In this situation you will need to discuss other treatment options with your doctor
  • If your symptoms impact on continued and significant weight loss then you should discuss this with your dietitian and/or doctor as alternative treatments may be required based on nutrition support advice.

Please contact your dietitian should you require further information. Otherwise see below for some online resources that you may wish to access:

  • GUTS UK! Gastroparesis (
  • GUTS UK! Functional Dyspepsia (
  • British Society of Gastroenterology guidelines on the management of functional dyspepsia (
  • Video;13 minute introductory overview of Functional Dyspepsia (

Department of nutrition and dietetics
3rd Floor East
250 Euston Road
London NW1 2PG

Direct line: 020 3447 9289
Switchboard: 0845 155 5000
Extension: 79289
Fax: 020 3447 9811

Page last updated: 09 May 2024

Review due: 30 September 2025