High-Fiber and Low-Fiber Foods

Why is fiber important for people with cancer? 

A person with cancer might need to lower or increase fiber in their diet if they: 

What is dietary fiber? 

Dietary fiber (often just called fiber) is the part of plant foods that we can't digest. Fiber is richly found in certain plant foods, including legumes or beans, whole grains, fruits and vegetables, and nuts and seeds.  

What is soluble and insoluble fiber?  

Dietary fiber can be either soluble or insoluble.  

Soluble fiber attracts water into the intestines and becomes a gel. It can help lower blood sugar and cholesterol levels. Foods higher in soluble fiber include: 

• Apples 

• Bananas 

• Citrus fruits 

• Beans 

• Berries 

• Oats 

• Peas 

Insoluble fiber doesn’t dissolve in the stomach. It can help move food through your digestive system and bulk up stool to help prevent constipation. But it can also have rough, hard bits that irritate the intestines as it passes through. Foods higher in insoluble fiber include: 

• Nuts and seeds 

• Some vegetables 

• Whole grain foods 

What is a low-fiber diet?

A low-fiber diet means you eat foods that do not have a lot of fiber. If you have certain medical problems, are having surgery, or are getting certain treatments for cancer, you may be asked to reduce the amount of fiber in your diet to rest your bowels (or intestines). A low-fiber diet reduces the amount of undigested food moving through your bowels, so that your body makes a smaller amount of stool. Low-fiber foods can be helpful if you have diarrhea, cramping, or trouble digesting food. Foods with little soluble fiber can often be eaten in small amounts (depending on why you're on a low-fiber diet) because the sof fiber gel doesn't irritate the intestines the same way.

How to eat a low-fiber diet

Here are low-fiber foods you can eat with tips to help you cook them if you’re restricting your dietary fiber. To see what foods you should avoid while on a low-fiber diet, you can find a list of high-fiber foods on this page. Keep in mind if you are on a “low-residue diet,” your food choices are even more restricted than those listed below. (A “low-residue diet” limits fiber plus certain other foods that might be difficult to digest.)

Low-fiber proteins: meat, fish, poultry, tofu, and nut products 

• Tender cuts of meat 

• Ground meat 

• Tofu 

• Fish and shellfish 

• Smooth peanut butter 

• Eggs 

Bake, broil, or poach meats, and use mild seasonings. Try preparing meats as stews, roasts, meatloaves, casseroles, sandwiches, and soups using ingredients on the approved lists. Scramble, poach, or boil eggs; or make omelets, soufflés, custard, puddings, and casseroles, using ingredients noted below. You might want to ask your doctor, nurse, or dietitian about other foods may be OK for you to eat and find out when you can go back to your normal diet. 

Low-fiber dairy foods: milk and cheese 

• Milk, chocolate milk, buttermilk, and milk drinks 

• Yogurt without seeds or granola 

• Sour cream 

• Cheese 

• Cottage cheese 

• Custard or pudding 

• Ice cream or frozen desserts (without nuts) 

• Cream sauces, soups, and casseroles 

You can use these items in desserts, snacks, or breads. Use in small to medium amounts and only if they don’t cause problems for you. 

Low-fiber bread, cereals, and grains

• White breads, waffles, French toast, plain white rolls, or white bread toast 

• Pretzels 

• Plain pasta or noodles 

• White rice 

• Crackers, zwieback, melba, and matzoh (no cracked wheat or whole grains) 

• Cereals without whole grains, added fiber, seeds, raisins, or other dried fruit 

Use white flour for baking and making sauces. Grains, such as white rice, Cream of Wheat, or grits, should be well-cooked. Include the above grains in casseroles, dumplings, soufflés, cheese strata, kugels, and pudding.

Low-fiber vegetables and potatoes

• Tender, well-cooked fresh or canned vegetables without seeds, stems, or skins 

• Cooked sweet or white potatoes without skins 

• Strained vegetable juices without pulp or spices 

You can also eat these with cream sauces, or in soups, soufflés, kugels, and casseroles. 

Low-fiber fruits and desserts 

• Soft canned or cooked fruit without seeds or skins (small amounts) 

• Small amounts of well-ripened banana 

• Strained or clear juices 

• Small amounts of soft cantaloupe or honeydew melon 

• Cookies and other desserts without whole grains, dried fruit, berries, nuts, or coconut 

• Sherbet and popsicles 

Serving suggestions include gelatins, milk shakes, frozen desserts, puddings, tapioca, cakes, and sauces. 

Other low-fiber foods

• Mayonnaise and mild salad dressings 

• Margarine, butter, cream, and oils in small amounts 

• Plain gravies 

• Plain bouillon and broth 

• Ketchup and mild mustard 

• Spices, cooked herbs, and salt 

• Sugar, honey, and syrup 

• Clear jellies 

• Hard candy and marshmallows 

• Plain chocolate

Liquids and drinks for a low-fiber diet

Keep in mind that low-fiber foods can cause fewer bowel movements and smaller stools. You may need to drink extra fluids to help prevent constipation while you are on a low-fiber diet. Drink plenty of water unless your doctor tells you otherwise, and use juices and milk as noted above. 

What is a high-fiber diet?

A high-fiber diet means you eat foods that are high or rich in dietary fiber. Dietary fiber has long been linked to a lower risk of certain types of cancer, including colorectal cancer. Because of this, many people who have not been diagnosed with cancer follow a high-fiber diet to try to prevent getting cancer. And some people living with cancer might choose high-fiber foods to help prevent other cancers from starting. Fiber can also promote heart health and can help a person maintain or lose body weight by helping to control cholesterol and blood sugar levels. 

If a person with cancer has no special dietary restrictions to follow during and after treatment, they might choose to follow a high-fiber diet to stay as healthy as possible.  But some cancer treatments can cause problems with the stomach and intestines. Adding high-fiber foods might increase those problems. If this happens, talking to a dietitian and cutting back on fiber can help.  

How to eat a high-fiber diet 

Here are high-fiber foods you can eat with tips to help you cook them if you’re following a high-fiber diet or want to increase fiber in your diet. To see what foods you should avoid while on a high-fiber diet, you can also find a list of low-fiber foods on this page.

High-fiber protein: meat, fish, poultry, and legumes 

• All beans, nuts, peas, lentils, and legumes 

• Processed meats, hot dogs, sausage, and cold cuts 

• Tougher meats with gristle 

High-fiber breads, cereals, and grains

• Brown or wild rice 

• Whole grains, cracked grains, or whole wheat products 

• Kasha (buckwheat) 

• Cornbread or cornmeal 

• Graham crackers 

• Bran 

• Wheat germ 

• Nuts 

• Granola 

• Coconut 

• Dried fruit 

• Seeds 

High-fiber vegetables and potatoes

• All raw or steamed vegetables 

• All types of beans 

• Potatoes with skin 

• Peas 

• Corn 

• Cabbage, broccoli, cauliflower, Brussels sprouts, and greens 

• Sauerkraut 

• Onions

High-fiber fruits and desserts 

• All raw or dried fruits 

• Berries 

• Prune juice, prunes, and raisins 

Other high-fiber foods

• Marmalade 

• Pickles, olives, relish, and horseradish 

• Popcorn 

• Potato chips