Fiber. You can't get enough of it. It's critical for digestion, lowering your risk for heart disease and just for overall good health. When we think fiber, we first (and sometimes only) think leafy greens and whole grains. While those are great sources of this miraculous substance, there are plenty of other sneaky foods with a surprisingly high dose of fiber. The Institute of Medicine recommends women eat at least 25 grams of fiber a day. Instead of endlessly consuming spinach smoothies to get your 25 g's, next time you're intestines are craving a bit of regularity, reach out for one of these five fiber-filled snacks:

Avocados: Avocados are creamy, delicious and a must-have at any BBQ. In addition to their high-level of good fat, they also pack more fiber per ounce than any other fruit. (Yup, these green babies are surprisingly considered fruits.) An average-sized avocado has a whopping 14 grams of fiber, even more than a serving than most wheat- or bran-based cereals.

Cocoa Powder and Dark Chocolate: Yet another reason to eat chocolate (in moderation, of course!) is it's high-dosage of fiber. All the fiber in the cocoa beans is contained in cocoa powder. It has 9 grams of fiber per ounce or 2 grams per tablespoon. Snack on a serving of 70 percent cacao or higher dark chocolate or mix a bit of cocoa power into your morning coffee.

Sundried Tomatoes: Not only are sundried tomatoes brimming with iron and potassium, they're also packed with fiber. One-hundred grams of sundried tomatoes provides 12.3 grams of fiber, that's about or 6.6 grams per cup, Blend them into sauces, top them on your pizza or toss 'em in your salad.

Popcorn:
Movie theatres have succeeded in giving popcorn a bad rap. (Sure, if you douse anything in pure butter, it's going to be a health hazard.) Light, homemade popcorn is a great source of fiber and whole grains. Each serving packs four grams of dietary fiber. To make popcorn at home, heat olive oil in a medium sauce pan, add a layer of kernels once hot and cover. Once popping begins, toss the pan to prevent burning. Once popping stops, remove from heat, add salt or toppings of your choice and enjoy.

Artichokes:
An average-sized artichoke contains only 60 calories per serving and is an excellent source of dietary fiber. With a whopping 6 to 7 grams per serving, it packs more fiber than a cup of oats, broccoli and prunes. Boil or steam an artichoke for 30 minutes for a perfect low-cal, high-fiber snack.