Protein supplement companies spend billions on advertising that you should be taking their products in order to build muscles and lose weight. However outrageous their claims may be, people with different goals need different amounts of proteins. Your protein intake should be the same as how much your body uses to function.

Adults

The Recommended Daily Value (RDA) suggests that typical healthy adults should consume 0.8 gram of protein per kilogram. A 70-kg man would need about 56 grams of protein while a 55-kg woman would need about 44 grams of protein. Any excess protein will be converted to body fat for storage.

Children and Teens

As a child grows, their need for protein gradually drops as they reach toward age 18. Toddlers typically need about 1.1 grams of protein per kg. By the time they reach kindergarten age, they need about 0.95 g/kg. At puberty, their protein intake is slightly more than the RDA adult recommendation.

Infants

Infants need the most amount of protein in their diet (1.6 to 2.2 g/kg) because of their high metabolic rate and early growth and development for their immune system, bones, and muscles.

Athletes

Because athletes are continually breaking down tissues during training, they need more protein than an average person (1.2 to 1.8 grams of of protein per kg). Endurance athletes (marathoners, triathletes) require the most amount of protein because the glycogen stores in their muscles are often exhausted. Contrary to popular belief, strength and power athletes do not need a lot of protein; rather, they need to consume more carbohydrates to fuel their performance and to be stored as glycogen in their muscles.

Pathology

People who have acute illnesses or recovering from an illness need a high protein intake, such as those suffering from burns, fevers, and infections. The range of protein intake varies from each patient.

Source:

"Perspectives in Nutrition"; Gordon Wardlaw and Margaret Kessel; 2002

"Ultimate Sports Nutrition;" Ellen Coleman; 2004

Resource:

Information about nutrition