You won’t hear this advice often: Leave fiber out of your diet. It’s the opposite of typical dietary recommendations for good health. This low-fiber diet, sometimes also called the low-residue diet, is a strategy for diverticulitis treatment and treating other gastrointestinal sensitivities. A low-fiber diet is often defined as containing no more than ten grams of fiber each day.
“The purpose of the low-residue diet is to reduce roughage that generates cramps, gas and other symptoms,” says Dr. Wilson Jackson, a gastroenterologist based in Harrisburg, Pennsylvania. While the term low-residue diet is no longer used by the Academy of Nutrition and Dietetics, low-fiber and low-residue are still used interchangeably.
The Issue With Fiber
For most Americans, the problem with fiber is that we just don’t eat enough; in fact, 95% of us consume less than the recommended amount of 25 to 30 grams from whole foods each day.
Fiber is the indigestible component of plants we eat — such as whole grains, legumes, vegetables, fruits, nuts and seeds — and it plays a crucial role in gut health.
“Eating high-fiber foods leaves a residue in the gastrointestinal tract that adds bulk to the stool, draws liquid into the bowel and pushes stool out,” explains Katrina Hartog, a registered dietitian and senior director of clinical nutrition at Lenox Hill Hospital in New York City.
Furthermore, fiber acts as a broom, sweeping carcinogens, allergens and environmental toxins out of the body before they can cause harm. There are several different types of fiber, which vary in terms of solubility, viscosity and fermentability.
[Read: What Is Gut Health?]
Eating high-fiber food is also associated with:
— A healthy population of gut bacteria.
— Cancer prevention (especially colon, breast and gastric cancers).
— Support of mood and cognitive functions.
— Improved insulin sensitivity and a lower risk of developing Type 2 diabetes.
— Healthier bones — some forms of soluble fiber increase the bioavailability of minerals, including calcium, helping to keep your skeleton strong.
Despite the benefits, digesting fiber can irritate the GI tract in someone with a sensitive gut, causing:
— Gas. Gut bacteria generate gas as they break down fiber. “The gas will stretch out and affect pressure sensors in the gastrointestinal tract, which can lead to cramps,” Jackson says.
— Speedy transit times. Fibrous foods move through the GI system faster than nonfibrous foods. “That can be painful, especially if you couple that with an inflammatory condition,” Jackson notes. Some research has found that individuals who eat more than 30 grams of fiber per day have GI transit times of less than 75 hours. However, those eating less roughage have up to 124 hours of transit time. Additionally, certain medical conditions, including diverticulitis, also speed up transit time.
— Fluid buildup. Under normal conditions, the intestines remove the water as food moves through the intestines. If that undigested food moves more quickly than expected, though, there isn’t enough time to absorb the water. “When undigested molecules rumble through the GI tract, there are faster shifts in fluid than normal, which can cause diarrhea,” Jackson says. “The molecules pull fluid in faster than it can be pulled out.”
Low-Fiber Diet for Diverticulitis and Other Gastrointestinal Issues
The low-fiber, or low-residue, diet offers a break from fiber-induced GI distress. A low-fiber diet helps ease GI tract irritation and reduces stool frequency and bulk.
On a low-fiber diet, you’ll have to eliminate just about all fiber-rich foods from the menu, including:
— Whole grains, such as whole-grain cereals, pasta and bread. Cereals or bread containing dried fruit, coconut, seeds and nuts must also be avoided.
— Most vegetable choices should be limited to a ½ cup serving size at a meal, and no more than two to three servings total spread throughout the day. Sweet potatoes, white potatoes, pumpkin and winter squash should be avoided completely. Vegetables with seeds, stems or skins should also be shelved until you’re feeling better.
— All raw fruit needs to be avoided except for stone fruit with the skin removed (peaches, apricots, plums and nectarines). Some, but not all, experts believe that bananas and soft melons are also alright to eat raw.
— Legumes such as kidney beans, lentils and peanuts. Crunchy peanut butter and all nut butter (such as almond butter) should also be eschewed for the time being.
Low-Fiber Diet Examples
The low-residue diet features easy-to-digest foods that won’t irritate your GI tract. Low-fiber foods include:
— Refined grains instead of whole grains. Refined grains have been processed, which removes the grain’s fibrous (and most nutritious) portions. Examples include white flour or anything made with it (like white bread, tortillas or pasta), white rice and puffed (white) rice cereal. Cream of wheat, cream of rice or grits can be consumed instead of whole-grain or bran cereals.
— Soft, well-cooked fruits and vegetables. “Remove the seeds and skins of fruits and vegetables, which have a lot of fiber, and then cook the foods for a long time. The cooking process will break down some of the fiber,” Hartog says. (Canned vegetables are especially soft.) Eating a ½-cup of green beans, carrots, spinach, lettuce, or tomato at each meal is often fine for people on a low-fiber diet. Canned fruit, applesauce and fruit juices are acceptable alternatives to fresh fruit.
— Lean proteins. “Most proteins will work if they’re tender and don’t have a lot of fat — like eggs, chicken breast or cod,” Hartog says. Tofu, smooth peanut butter and sunflower seed butter can also add a protein boost to your meal without risking discomfort from too much fiber.
— Dairy foods and non-dairy alternatives. All dairy and non-dairy products are low-fiber. You’ll need to avoid large amounts of yogurt that contains chunks of fruit, seeds or nuts. Hard cheeses, such as cheddar, should be limited to 1 ½ ounce. Some people feel better if they choose lactose-free cow’s milk or plant-based milks such as almond or rice milk; this is especially likely for those trying to get diarrhea under control.
What does a day of meals look like on the low-residue diet?
Breakfast: Scrambled eggs and white toast.
Lunch: A cup of chicken noodle soup and half a tuna sandwich on white sourdough bread. Snack: Saltine crackers.
Dinner: Chicken breast, carrots and canned green beans.
In addition, you’ll need to drink lots of water and might feel better avoiding beverages with too much sugar. “Sugary juices can run through the system too quickly and cause loose stool,” Hartog says.
People Who Should Try a Low-Residue Diet
The low-residue diet is intended for people with certain GI conditions. They include:
— Diverticulitis. Diverticulitis is an acute infection of diverticula or little pockets in the wall of the colon. Low-fiber, bland diets remain a standard intervention during symptomatic flare-ups of diverticulitis.
— Ulcerative colitis or Crohn’s disease. A flare-up of one of these conditions throws off GI health and requires bowel rest, sometimes complete bowel rest and parenteral nutrition (wherein nutrients are delivered via IV). In Crohn’s disease, a low-fiber diet helps to prevent bowel obstruction and maximize nutrient and calorie absorption. There is some evidence that corn, wheat, potatoes, apples, mushrooms and oats, specifically, increase the chances of a Crohn’s disease flare.
— Irritable bowel syndrome. In a controlled trial of 204 participants, four weeks of a low-fiber (less than 10 grams per day) diet substantially improved symptoms for about half of the volunteers.
— Infection of the GI tract. This is often caused by food poisoning from bugs such as Salmonella or E. coli. Many doctors recommend bland, low-fiber foods when recovering from a gastrointestinal infection. Perhaps you’ve eaten crackers, toast, gelatin, applesauce and broth while on the mend. None of these foods contain much fiber, if any. Many medical experts will also recommend avoiding milk and other lactose-containing dairy products, caffeine, alcohol, and fatty or highly-seasoned foods.
— Cancer. This includes people experiencing cancer of the GI tract or GI discomfort due to certain cancer treatments (such as radiation therapy) or cancer surgery. Some cancer treatments make it more difficult to pass stool. A low-fiber diet can promote easier movement of food through the digestive tract, lessening the chances that a bowel obstruction will form.
— After GI surgery. Digestion may be disrupted after GI surgery. After surgery, you’ll likely start your recovery with nothing by mouth (except maybe a few ice cubes), progress to clear liquid and slowly work your way up to a low-fiber diet.
Low-Residue Diet Risks
While the low-residue diet may help ease gastrointestinal symptoms, it still comes with some risks. For example:
— The low-residue diet lacks enough nutrients to keep you healthy.
— High amounts of starch-heavy foods may lead to weight gain.
— Constipation can occur, especially if you don’t drink enough fluid.
In the short term, you can avoid potential risks by:
— Working with a dietitian to include as many nutrients as possible in your diet.
— Taking a chewable multivitamin.
— Working with your doctor to control blood sugar levels.
— Exercising daily to maintain good health and ward off weight gain.
But the low-residue diet isn’t meant for the long term.
“For acute issues, we’d recommend being on the diet for five to seven days and then adding fiber back in. But it’s all patient-specific,” Hartog says. “If you and I were on a low-residue diet, you might be able to add back foods quicker than I would or vice-versa.”
Long-Term Treatment of Diverticulitis and Other GI Issues
It may take longer than a week to get GI symptoms under control in some cases. That may be safe for some people.
“If you take a well-nourished person with a Crohn’s disease flare, they can safely sustain the low-residue diet for three months, presuming they’ll get back on a regular diet,” Jackson says. “But if you maintain this diet for years on end, there are deficiencies that can develop, and you’ll need to find other ways to get healthy foods into your diet.”
That can be especially challenging for people with GI cancer, whose treatment may last for many months.
In those cases, Jackson suggests slowly adding healthy, fibrous foods back into your diet and breaking them up with a food processor or blender. “For example, take kale, put it in a blender and then drink it. You can do the same thing with an apple. You won’t have a lot of the side effects that normally come with those foods,” he says.
But sustaining any restrictive diet is difficult. Don’t hesitate to ask for help. “Get in touch with a dietitian or use internet resources with well-researched recommendations and ways to manage your condition,” Jackson says. “And remember to keep your doctor in the loop about how you’re feeling.”
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Update 04/20/22: This story was previously published and has been updated with new information.