Harvard Health Letter

Why doctors keep pushing fiber

Easy ways to pump more into your diet.

Fiber is the nondigestible component of plant food that can help reduce risk for cardiovascular disease, diabetes, and obesity. But not everyone fits enough fiber into the diet. "The typical American diet includes 15 grams of fiber a day, but the daily recommendation is 25 to 35 grams per day," says registered dietitian Stacey Nelson, clinical nutrition manager at Massachusetts General Hospital.

How much fiber does it take to fight chronic conditions?


Fiber Requirement

Evidence based on current data


30–50 grams daily from whole foods

Dietary fiber intake lowers blood sugar levels compared with a low-fiber diet.


20–27 grams daily from whole foods

In the prospective Nurses' Health Study, women who consumed more fiber weighed less than women who consumed less.

Heart disease

12–33 grams daily from whole foods

Dietary fiber intake may improve blood fat levels and reduce indicators of inflammation.

Fiber supplements seem an easy choice, but Nelson says whole-food sources might be best. If reading food labels is a hassle, Nelson suggests getting rid of as many prepackaged and processed foods as you can. "The more you process a food, the more nutrition and fiber you lose," says Nelson. She also recommends using snack time to sneak in more fiber. Ditch chips and go for fruit, veggies, or whole-grain crackers. Dip them into bean dips instead of onion dip. Munch on popcorn instead of pretzels. The more plant-based whole foods you eat throughout the day, the more fiber you'll naturally fit into your diet.

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