Some simple ways you can increase dietary fiber include switching to rye or dark bread from white bread, to oat-based cereals or whole wheat cereals, and to baked potato with skin from french fries. Fresh or dried figs, prunes, apricots, peaches, and various berries, beans, peas, corn, and carrots are all healthful alternatives. Another easy way is to eat fruits (such as oranges, apples, and prunes) instead of just drinking their juices, which are practically devoid of any fiber. To avoid the digestive side effects such as gas and bloating, you should increase your dietary fiber slowly to reach desirable levels of more than 20 grams per day.
(Source: Every Heart Attack is Preventable, by Michael Mogadam, M.D.)