Fiber Intake Calculator

The US National Academies set an Adequate Intake of 14 grams of fiber per 1,000 kcal eaten, which works out to the amounts below for typical calorie intakes. The UK recommends 30 grams a day for adults, and the European Food Safety Authority considers 25 grams a day adequate for normal bowel function. If you enter your calories, the calculator shows the 14 g per 1,000 kcal figure for your own intake.

Soluble fiber, found in oats, barley, beans, lentils, apples and citrus fruit, forms a gel in the gut. It slows the absorption of sugar and helps lower LDL cholesterol. Insoluble fiber, found in whole grains, wheat bran, nuts and the skins of fruit and vegetables, adds bulk and helps food move through the gut, which prevents constipation. Most plant foods contain both, so eating a variety of whole grains, legumes, fruit, vegetables, nuts and seeds covers both kinds without needing to count them separately.

Choose whole-grain bread, pasta and rice instead of white; start the day with oats or a high-fiber cereal; add beans or lentils to soups, salads and sauces; keep the skin on potatoes and fruit; snack on fruit, nuts or vegetables; and aim for vegetables with every meal. A cup of cooked lentils alone provides more than half of a woman's daily target. Increase fiber gradually over two or three weeks and drink enough water, because adding a lot at once can cause bloating and wind.

High-fiber foods take longer to chew and digest, add volume without many calories, and slow the rise in blood sugar after a meal, so they help you feel full for longer. Studies consistently link higher fiber intake with lower body weight and less weight gain over time. Swapping refined grains for whole grains and adding beans, lentils and vegetables to meals is one of the simplest ways to improve a diet without counting calories.

Some people need to adjust fiber for medical reasons — for example during a flare of inflammatory bowel disease, after some bowel surgery, or with certain digestive conditions. If you have one of these, or ongoing digestive symptoms, follow the advice of your doctor or dietitian. Fiber supplements can help if your diet falls short, but whole foods also provide vitamins, minerals and other beneficial plant compounds that supplements do not.