Protein is an indispensable macronutrient required for the growth and maintenance of the body. Every cell needs protein to carry out metabolic functions of building and repairing. According to the US Department of Agriculture food guide, proteins should constitute 26 percent of your daily caloric intake.
Average Protein in Daily Diet
The typical American diet is defined by a greater intake of red meat, high-sugar desserts, high-fat foods and refined flour. It also usually contains high-fat dairy products, artificially sweetened drinks and eggs. According a National Health and Nutrition Examination Survey from 2007-2008, this diet provides a net protein intake of 101.9 grams to males and 70.1 grams to females a day—more than double the recommended daily allowance as suggest by national dietary guidelines.
Proteins and the Typical Diet
According to the NHANES 2007-2008, proteins contribute 16 percent of the total energy consumption in calories for both males and females above age 20. Breakfast provides 15 percent, lunch provides 28 percent and dinner provides 44 percent of the average daily intake of protein. Snacks, however, contribute to only 13 percent of the daily intake.
Estimated Average Requirements for Proteins
According to the Food and Nutrition Board, Institute of Medicine, your average requirement of protein depends on your age and sex. In growing children and adolescents, it is slightly higher to provide enough building material for growth and development. The protein requirements are also high in convalescents, pregnant and lactating women, and anyone undergoing severe stress or disability.
For males age 9 to 13 and 14 to 18, the Expected Average Requirements for protein are 0.76 and 0.73 grams per kilogram body weight per day, respectively. For females of the same age groups, they are 0.76 and 0.71 grams per kilogram body weight per day. For both males and females above the age of 18, the Expected Average Requirements are between 0.66 and 0.8 grams per kilogram body weight per day.
Dietary Protein Sources
The major dietary sources of protein in the American Diet are animal products like red meat, poultry, fish, eggs, milk and milk products. Animal proteins are of high biological value because they contain all nine essential amino acids, though they can be loaded with saturated fats, so choose lean meats and dairy products. Plant proteins, on the other hand, do not offer all the essential amino acids in one food source; the exception is quinoa, which is a complete protein. Therefore, if you are a vegan, you need to eat complementary protein sources, such as a wheat and legume dishes to maintain high biological value of your proteins.