Choosing Your Foods

Dietary treatment for CSID is based on sucrose, isomaltose, and maltose restriction. The degree of restriction is patient-specific. Patients with CSID should plan their diet in conjunction with their physician and registered dietitian (RD). Every patient’s case of CSID is unique, so diets can vary considerably. It is imperative to keep food logs or food diaries when figuring out a CSID diet. Every item a patient with CSID eats or drinks should be recorded along with the time of ingestion. Recording serving size or weight can also be helpful. Also write down the timing of any symptoms the patient experiences such as bloating, gas, diarrhea, or abdominal pain. This detailed food record will help the RD plan a diet more effectively. When introducing new food items, it is recommended that you wait at least 3 days before introducing an additional food item.


In order to first determine sucrose tolerance levels, it may be necessary to remove all starches from a patient’s diet. Sucrose, a carbohydrate, is typically “table sugar” or “white sugar,” and can be added to many foods. There are other forms of sucrose, and sucrose is also found naturally in some foods. Sucrose digestion is a problem for most CSID patients. Sucrose tolerance levels may be determined by introducing increasing amounts of sugar-containing foods slowly, with Sucraid® (sacrosidase) Oral Solution to limit symptoms.


Starch is a component of carbohydrates along with fiber and sugars. Starches are typically found in grains like wheat and in potatoes, corn, and rice. In the typical American diet, 60% of total calories consumed originate from carbohydrates. Approximately 60-80% of starch digestion in the small intestine is by the disaccharidase (enzyme) sucrase-isomaltase and 20-40% is by the disaccharidase (enzyme) maltase-glucoamylase. Patients with CSID have varying amounts of these enzymes and, therefore, starch tolerance. It is important to determine starch tolerance by introducing starch-containing foods gradually. Some patients with CSID eat normal amounts of starch, some can eat limited amounts of starch, and some cannot eat any starch. Patients should consult with their physicians and RDs to discuss how much starch can be tolerated. If the patient or caregiver knows his/her disaccharidase results, they may be used as an initial indication of starch digestion capacity based on the rates of maltase-glucoamylase activity. There are no FDA-approved supplemental enzymes for starch digestion.


Once it is determined how much sucrose a patient can tolerate, with and without Sucraid® (sacrosidase) Oral Solution, starches can be added to the diet slowly, watching carefully for symptoms. Starch digestion capacity should be confirmed by starch food challenges.


Physicians and RDs can use the food composition tables on this website to begin to build an appropriate CSID diet for each patient. For fruits and vegetables, physicians and RDs should consult the food composition tables to determine acceptable foods within a patient’s sucrose and starch limits. Below are some general diet guidelines that should be discussed with a patient’s physician and RD. When beginning a diet, patients could start with the food items that most patients with CSID can tolerate and then add other food items over time as tolerated. An RD can assist patients in using a food log and determining food tolerances.




Fruits Tolerated by
Most CSID Patients
Fruits Tolerated by
Some CSID Patients
Fruits Tolerated by
Few CSID Patients
boysenberrieswatermeloncantaloupe (rockmelon)
cranberries, freshgrapefruit
figs, rawhoneydew melon
lemonspassion fruit
pearsmandarin oranges



Vegetables & Legumes Tolerated by
Most CSID Patients
Vegetables & Legumes Tolerated by
Some CSID Patients
Vegetables & Legumes Tolerated by
Few CSID Patients
alfafa sproutsedamame soybeansbeets
*artichoke, globejicamablack beans
arugulaleekblackeyed peas (cowpeas)
*asparagusokrabutternut/buttercup squash
bamboo shootspumpkincarrots
bok choysnow peascassava (yuca)
*broccolitempehchickpeas (garbanzo beans)
*brussels sproutstofucorn
*cabbageyellow wax beansgarlic
*cauliflowergreen peas
celerykidney beans
chicorylima beans
chivesnavy beans
collard greensonions
cucumberpinto beans
green beanssplit peas
kalesweet potatoes
mung bean sprouts
mustard greens
peppers (red, yellow, green)
spaghetti squash
yellow squash
zucchini (courgette)

*It should be noted that artichokes, asparagus, broccoli, brussels sprouts, cabbage, and cauliflower can cause gas in all individuals, not just patients with CSID, so consumption of these should be monitored closely.





When starting a CSID-friendly diet, it is recommended that a patient consume no grain-based starches at all. This is necessary to determine sucrose tolerance levels before introducing starches. Once sucrose tolerance levels have been established, patients can begin to introduce starches slowly. Some fruits and vegetables contain starch. Well-known starchy fruits and vegetables include banana, corn, carrots, legumes (beans), and potatoes. Fruit and vegetable starch content should be taken into consideration when introducing starches. Patients can use the Food Composition Tables on this website to determine starch levels in food. Once sucrose tolerance and non-grain starch tolerance levels have been established, grain-based starches may be introduced.


Some patients find that slowly-digestible carbohydrates such as whole grains are easier to tolerate. Some starches digest more slowly in the small intestine and will slow gastric emptying, the rate at which food moves through the digestive tract. Because the small intestine and large intestine are getting smaller amounts of starch at a time, a patient may be better able to tolerate the starch. Good choices are whole grain breads or those made with stone-ground flour instead of white breads. Breakfast cereals or grains that contain whole oats, barley, or bran are better options than more processed refined cereals. Whole-wheat pasta, quinoa, lentils, brown rice, or wild rice are better options than more processed grains like white rice. Patients do need to read labels carefully because some whole grain products have added sugars including sucrose.


In general, most food items made with white flour may be difficult for a patient with CSID to consume without symptoms. Over time, these food items may be added to the diet once sucrose and starch levels have been established, and a patient is symptom-free. It has been noted that some patients with CSID are able to increase their starch tolerance as they grow older and their digestive tract lengthens.



Meats and Other Sources of Protein

In general, most patients with CSID can eat plain beef, plain pork, plain lamb, plain fish, plain turkey, plain chicken, and eggs. “Plain” meat means cooked with no sauce and no seasonings. Meats can be cooked with butter, oils, salt, and pepper. Patients should avoid breaded meats until starch tolerance levels have been established. Patients should also avoid processed meats such as bacon, sausage, luncheon meat, deli meat, liverwurst, and pâté since many of these are cured with sucrose or have starch fillers. These food items may be added at a later date once appropriate sucrose and starch tolerance levels have been established through food diaries/logs.


Most patients with CSID can tolerate eggs. Nuts and nut butters can be a great source of calories for a patient with CSID. It is recommended that these be avoided until sucrose and starch levels have been established with food diaries/logs. Starch and sugar components for different varieties of nuts can be found in the food composition tables on this website. Legumes and beans can be added to a CSID patient’s diet once sucrose and starch levels have been established by food logs/food diaries. Most legumes and beans are starchy, so this should be taken into consideration. Most patients with CSID can tolerate tofu.




Most patients with CSID can eat dairy products like cow’s milk, ricotta cheese, plain cottage cheese, sour cream, butter, cream, whipping cream, and hard cheeses (cheddar, colby, mozzarella, swiss, parmesan, and provolone). In addition, most patients can tolerate plain, unsweetened yogurt, yogurt sweetened with dextrose, and yogurt sweetened with fructose. Many patients eat full-fat dairy products to ensure they are getting enough calories. Over time a patient with CSID may be able to tolerate more dairy products than those listed above. Once sucrose and starch levels have been established (through food diaries or food logs), a patient can introduce additional dairy items to determine tolerance.


A minority of patients with CSID also have lactose  intolerance. Consult a physician and RD to see if milk products are expected to be tolerated. Patients with CSID should avoid processed cheeses or cheese products since many of these contain sucrose or starch fillers. Processed cheeses and processed cheese products are made from normal cheese and may include other unfermented dairy ingredients, plus emulsifiers, extra salt, food colorings, or whey. American cheese slices and Velveeta are examples of processed cheese products. Once the sucrose and starch levels have been established through food diaries or food logs, a patient can introduce additional dairy items to determine tolerance.





In general, most fats and oils such as butter, margarine, olive oil, and vegetable oil can be used without restriction for patients with CSID. In the case of margarines, it is always a good idea to read labels carefully for potential starch or sucrose content.





In general, patients with CSID can tolerate milk, water, diet soda, and homemade limeade or lemonade made with fresh juice and fructose or dextrose. Some patients can tolerate regular sodas (non-diet) that are sweetened with high fructose corn syrup. Sweetened sodas should only be tried under the advice of an RD or physician.





In general, most patients with CSID tolerate salt. Some patients tolerate pepper and others do not, as black pepper does have a small amount of sucrose and some starch. When starting a diet, it is recommended to use few other spices or seasonings in order to aid in clearly determining tolerance levels, as many spices contain sugar or starch fillers. Other spices can be added later once sucrose and starch levels have been established through food diaries/logs.


Other Tips

Parents/caregivers have noticed a few trends that have assisted in raising tolerance levels when adding starch to a CSID diet.


First, encourage food to be chewed well. For example, suggest chewing 30 times before swallowing. Salivary amylase is the first enzyme in the process of starch digestion, and starchy foods will break down more easily if exposed to salivary amylase in the mouth for an extended period. The more a food is chewed, the greater the exposure the starchy food has to this necessary enzyme.


Second, combine a high-starch food with a fatty food at the time of ingestion. Food time spent in the small intestine affects starch digestion. Increasing the time through the small intestine by incorporating the high-fat content food will allow the starch to have more exposure to pancreatic amylase, isomaltase, and maltase in the small intestine. An example would be serving cheese with a starchy vegetable.


Working with an RD is crucial to dietary success. Even though it might be difficult to find an RD who has experience with CSID, he/she will be able to demonstrate how to effectively write and manage a food log or diary and how to add foods by trial to the diet. They will also be able to network with other RDs that have experience with a CSID diet. When looking at the list above, it may seem like a very short list of foods someone with CSID can eat. Be assured that over time and by paying close attention to specific foods and related symptoms, the list of acceptable foods will grow substantially.