How Much Protein Should We Consume?
- In addition to building and repairing tissue, protein keeps the immune system functioning properly and is involved in the synthesis of hormones and enzymes. Protein can also be used as an energy source when there is an insufficient consumption of calories or carbohydrates. This occurs in the Atkins diet, in which dieters eat mostly protein and little to no carbohydrates. Because the Atkins diet is deficient in carbohydrates, the body has to use protein for energy.
- Protein is made up of 20 building blocks known as amino acids. These amino acids are classified as nonessential amino acids and essential amino acids. Essential amino acids cannot be manufactured in the body, and therefore they must be consumed through dietary protein. Meats, fruits, vegetables, grains, dairy products, legumes and protein supplements supply the body with essential amino acids.
- It's recommended that 0.4g protein should be consumed for every pound of healthy body weight (or approximately 0.8g protein per every kg of weight). For example, a man who weighs 150 lbs. needs approximately 60g of protein per day (150 x 0.4 = 60).
- Exercise affects daily protein requirements. The change in protein needs depends on the type of exercise (aerobic versus anaerobic), duration and intensity. For instance, a power lifter needs to supplement with additional protein, but someone who engages in light to moderate aerobic activity, such as power walking, doesn't need to supplement.
Total caloric intake also affects protein requirements. Generally, it's recommended that 15 percent to 30 percent of total caloric consumption come from protein. For example, a female with a caloric intake of 1,600 calories with 20 percent of her calories to come from protein should consume 320 calories (or 80g) of protein per day. To figure out the number of grams needed, divide the resulting number of calories by 4 (320 / 4 = 80). - Based on nutrition density, a ratio between the amount of protein in food in comparison to the amount of calories, tuna, shrimp and cod are the best sources of protein. Other good sources include fish, turkey, chicken, beef and dairy products. Many vegetarian sources, such as spinach, tofu, mustard greens, soybeans, quinoa, lentils and beans are also excellent sources of dietary protein.
