Fiber

Apples: One medium apple is packed with more than 4 grams of filling fiber. No surprise, then, that Penn State University researchers discovered that people who ate an apple before a meal consumed 15 percent fewer calories than those who didn't. Bonus: Apples are a strong source of disease-fighting antioxidants.

Eat them: Whole or chopped, sprinkled with cinnamon and microwaved for a minute to make a low-calorie apple pie—like treat.

Oatmeal: Whether you choose instant or old-fashioned, oats have one of the highest satiety rankings of any breakfast option. This whole-grain food is digested more slowly than most other carbohydrates, keeping blood sugar even and staving off that "I'm so hungry I could eat the fridge" feeling. One cup contains 8 grams of fiber, about a third of your daily needs.

Eat it: Cooked and topped with fruit or added raw to meat-loaf mix.

More fiber on the next slide.