All berries are incredibly beneficial sources of fiber, not ot mention potassium and vitamin C. Blackberries and raspberries contain the most fiber, but blueberries and strawberries are also great options. Use berries in your smoothie or just have them for a mid-afternoon or morning snack. Eating more of these beneficial sources of fiber will fill you up, optimize your energy, improve your mood, and help the scale move in the right direction in no time. What's your favorite source of fiber to eat? Sources: eatingwell.com, besthealthfoodstore.net, webmd.com