• Eggs are a good source of low-calorie protein.brown egg and white image by John Keith from Fotolia.com
  
  Protein represents your body's building blocks. For example, it replenishes lost blood, heals your injuries and scars, provides your system with new cells that develops your body, and it makes your hair and nails grow. While you can find protein in animal and most plant sources, some contain significantly fewer calories than others.
  
  

Egg Whites

• Eat egg whites if you must watch your calories but ensure that you also get sufficient protein. Each egg white has 3.6 g of protein, but only 17 calories, which means you can eat several without gaining weight and reach your recommended daily intake (RDI) of protein. To meet your RDI, eat 0.6 to 1.2 g of protein per kg per day. (Divide your weight with 2.2 to get how many kg you weigh.) Keep in mind that the yolk has more nutrients than the white.
  
  

Chicken and Turkey

• White turkey meat, with its 178 calories per four oz., contains slightly fewer calories than the same amount of white chicken meat, which contains 196. Chicken has 35.1 g of protein over turkey's 33.6 g per serving. Stay away from all dark poultry meat because it has more calories.
  
  

Beans

• A vegetarian should eat beans to reach his recommended daily intake of protein, while at the same time avoid gaining weight. Soybeans (edamame) contain the most protein and are low in calories--11.1 g per 1/2 cup cooked, and have only 127 calories. Tofu, a soybean product, has about 30 fewer calories for the same measure (fresh) and almost as much protein. Beans, such as black beans, lima beans, navy beans and kidney beans have the highest amount of protein--approximately 7.5 g per 1/2 cup cooked. With the exception of navy beans, which has slightly more calories, they all contain only approximately 113 calories per half cup. Lima beans have 8.9 g of protein, but only 115 calories per 1/2 cup. Be aware that "animal proteins such as meat, milk and cheese tend to be of a higher protein quality than plant proteins," according to the Vegetarian Society.
  
  

Fish

• White fish has a lot of protein and few calories. For example, 3 oz. of halibut has only 93 calories and 17.7 g of protein, while the same serving of salmon, has a comparable amount of protein but also 127 calories. Sardines in water have a few more grams of protein. However, they also have more calories--130 per can. Tuna contains only 70 calories per 1/4 cup and has 16 g of protein.