Protein is one of the basic building blocks of the human body, being about 16 percent of our total body weight. Muscle, hair, skin, and connective tissue are mainly made up of protein. Meat, fish, eggs, dairy products, legumes (beans and lentils), and nuts all have substantial amounts of protein. On the food pyramid, protein is found in the middle layer. 

20% to 30% of total calories

1000 calorie diet = 200 to 300 calories of protein a day. 

1200 calorie diet = 240 to  360 calories of protein a day. 

1400 calorie diet =  280 to 420 calories of protein a day. 

1700 calorie diet =  340 to 510 calories of protein a day. 

2000 calorie diet =  400 to 600 calories of protein a day.