Estrogen is a factor in the early growth and development of breast cancer and a study reported in the Journal of Clinical Oncology found that a diet with 20 – 30 grams of fiber per day can be helpful in lowering estrogen levels. One theory is that fiber interferes with the absorption of estrogen into the blood. Another theory is that people who eat more fiber consume less fat, and a diet that is high in fat is believed to increase the risk of developing breast cancer.
Are you getting enough fiber in the foods you now eat?  The U.S. Department of Agriculture's 2010 Dietary Guidelines recommends 25 grams of fiber per day for women and 38 grams daily for men, yet most Americans get only about 15 grams of fiber a day.
The good news is that high fiber foods are plentiful, delicious, and easy to fit to your diet:
Breakfast
Your first meal of the day lends itself to a big fiber boost because certain breakfast foods are loaded with fiber.  Have a cup of high fiber cereal and you’ll get up to 25 grams of fiber. Top it with ¾ cup of blueberries and tack on another 5 grams of fiber. Swap a slice of white toast for whole-wheat toast and pick up 3-4 grams of fiber.
Lunch
Opt for soup made with fiber-rich lentils or black beans and get 12 or 9 grams of fiber respectively per one cup serving.  At the salad bar, a salad with spinach, black beans, tomato, cucumber, onion, and shrimp tallies up to about 15 grams of fiber. Make your sandwich with whole wheat instead of white bread and get an extra 5 grams of fiber.
Dinner
Swap out starchy low fiber carbs such as white pasta and rice and add tasty sides, such as corn on the cob, baked potatoes with the skin, beans and squash, which are high fiber superstars. Making swaps like these can automatically add another 5 grams of fiber to your meal.
Snack
Popcorn is a great fiber-filled snack because 5 cups of popped popcorn contains 4 grams of fiber. Another idea: slice up apples or potatoes and bake them to a crispy, high-fiber crunch.
Drinks
If you enjoy smoothies get a big fiber boost by tossing some high fiber cereal, chia or flax seeds in the blender!
For more tips, delicious high fiber meal plans, recipes, and proven ways to lose weight and look great, check out my new book The Miracle Carb Diet: Make Calories and Fat Disappear – with Fiber!  
Tanya Zuckerbrot MS, RD, is a registered dietitian in New York City and author of the Miracle Carb Diet: Make Calories and Fat Disappear – with fiber as well as the bestselling F-Factor Diet. Follow Tanya on Facebook, Twitter and LinkedIn, and visit her website Ffactor.com.