Protein, carbohydrates and fats are the three nutrient categories that make up your daily diet. In terms of nutritional needs, protein falls right in the middle -- most of your calories should come from carbohydrates and the least of your calories from fats. Taking in enough protein each day ensures your body can build healthy skin tissue and maintain fluid balance and a healthy immune system.
On a food label, protein is measured in grams. To calculate how much protein you need on a daily basis, use this formula from the American Dietetic Association: Multiply your body weight in kilograms by 0.8 to 1.0 grams of protein. If you weigh 150 pounds, divide this number by 2.2 to obtain your weight in kilograms, which is roughly 68.2 kilograms. Multiply this number by 0.8 and 1.0 to obtain your daily needed protein range, which would be between 54.6 and 68.2 grams of protein per day.
The Centers for Disease Control and Prevention recommends anywhere from 10 to 35 percent of your daily calories come from protein sources. For women older than age 19, this amounts to about 46 grams of protein per day. Men older than age 19 should consume about 56 grams of protein per day. Protein is the major building block of muscle tissue, and men tend to have more muscle, which is why their recommendations are slightly higher.
If you are a competitive athlete or frequently lift weights to build muscle, you need more protein than the average person. Protein serves several extra functions in the active person, from serving as an energy source during exercise to repairing damaged muscles after a workout session. The Australian Institute of Sport recommends moderate-intensity endurance athletes take in about 1.2 grams of protein per kilogram of body weight per day while elite male endurance athletes need about 1.6 grams per kilogram of body weight. If you are in the early stages of muscle-building through resistance training, you need between 1.5 and 1.7 grams of protein per kilogram of body weight. However, if you have been training for some time, you typically need 1.0 to 1.2 grams per kilogram to maintain your muscle mass.
Now that you know how much protein you need each day, it's important to know where to find it. Protein is found in animal products such as meats, eggs, poultry, fish and dairy foods. Non-animal based protein sources include dry beans, peas, tofu, nuts and seeds. Whole grains, fruits and vegetables can provide smaller protein sources in your diet.