Choose heavyweights. To meet the 25- to 35-gram daily fiber quota, choose the foods that provide the most fiber in a serving: whole-grain bran cereals and legumes, then hearty whole-grain breads, and finally fruits and vegetables. A cup-and-a-half of raisin bran, for instance, will net you 12 grams of fiber, a sandwich made with two slices of 100 percent whole-wheat bread another 4 grams. Finish off your lunch with an apple (4 grams) and have a bowl of vegetarian chili for dinner (5 or 6 grams), and you'll easily cross the 25-gram finish line.
Find food first. Fiber supplements are OK in a pinch or to get you over that 25-gram hump if you simply can't manage to eat enough high-fiber foods daily. But when you get fiber from foods, you're also tapping into vitamins, minerals, and phytochemicals that come along for the ride. Experts believe it's the synergy of all these nutrients, most of which aren't contained in fiber supplements, that confers the most dramatic health benefits.
Go natural. You'll get higher levels of fiber if you eat products that come in nature's original packaging. Consume fruits and vegetables in their skin, a good source of roughage. (Rule of thumb: With a few exceptions, if you can put your fingernail through the skin, leave it on.) Regarding grains, the coarser, the better.