Diet-Smart Protein

Are you starting to find your so-called "diet" foods unsatisfying? The reason may be because they're lacking in protein, a nutrient that is both filling and calorie burning. That's right -- the building blocks of our bones and muscles can also fuel weight loss when added to your diet in healthy amounts. Foods high in protein can help slow the digestion process, leaving you feeling fuller longer. Plus, your body uses more energy when digesting protein than digesting a fat or carbohydrate, according to the Harvard School of Public Health. These factors help explain why studies have shown that people are more likely to decrease their caloric intake after eating protein. That doesn't mean you can just start adding any protein into your diet. Below you'll find ten foods that are low in calories, fat and saturated fats, and also pack more protein than you might expect.

More Fat-Fighting Properties

Protein may also boost the hunger-fighting properties of the hormone peptide YY (PYY). A study conducted in 2006 by Rachel Batterham of University College London found that enhanced-protein meals stimulated a greater release of PYY than either high-fat or high-carbohydrate meals, resulting in greater satiety.

"The findings show that PYY deficiency can cause obesity," the study's author, Batterham said. "One potential weight loss strategy is therefore to increase the satiating power of the diet and promote weight loss through the addition of dietary protein -- harnessing our own satiety system."

In order to maintain healthy body functioning like muscle growth and development during childhood, adolescence and pregnancy, it is recommended to consume seven grams of protein for every 20 pounds of body weight -- or about 50 to 65 grams of protein each day for the average person, but more may be better for your waistline.

"There is evidence that diets that are higher in protein than the Recommended Dietary Allowance (RDA) can help satiety," says Bethany Thayer, MS, RD and spokesperson for the American Dietetic Association. Distributing your calories such that 50 percent are from carbohydrates, 30 percent from fat, and 20 percent from protein will ensure you get more than the RDA, says Thayer. To capitalize on this hunger-curbing benefit of protein, try getting some at any meal and snack you have throughout the day.

Too Much of a Good Thing

Most Americans get a lot more than the RDA, which is where it gets tricky, because often that protein comes from unhealthy sources, says Thayer. People who subsist on high-protein diets like the Atkins Diet may be replacing lower-fat carbohydrates with proteins that are high in unhealthy and saturated fats which can lead to weight gain. To avoid this, be careful to choose proteins that are high in fiber, low in saturated fats and not packed with calories, says Thayer.

High-protein diets can also lead to some undesirable side effects. As the kidneys work to get rid of the nitrogen that comes along with protein, they eliminate some nutrients like calcium, which is why calcium loss caused by high-protein diets has been linked to weaker bones, explains Thayer.

Healthier High-Protein Alternatives

Try lean chicken, turkey, beef, or pork. Fatty fish is another option that provides both unsaturated fats and is a good source of omega 3s. Proteins from meat, other animal products and soybean products are complete proteins, meaning they provide the nine essential amino acids we can't produce on our own. Plant proteins are incomplete and must be combined to ensure you get the daily amino acids needed for functioning.

"Beans are one of the best sources of protein," says Thayer, "Because they're very low in fat, but provide fiber along with the protein, so they are very filling." She suggests eating a cup of beans, which has about 200 calories and 15 grams of protein, and looks and feels so filling that most people can't even finish the whole serving.

*Approximate values based on information from the USDA National Nutrient Database for Standard Reference, where available.