In recent years there has been considerable interest in the benefits of high-protein diets. This study determined current usual intake of protein in America. Using the most recent data from the National Health and Nutrition Examination Survey, 2003-2004, usual protein intake for Americans aged 2+ years was estimated. Usual protein intake was calculated on a grams per day, grams per kilogram ideal body weight, and a percentage of calories basis. Protein intake averaged 56 +/- 14 g/d in young children, increased to a high of approximately 91 +/- 22 g/d in adults aged 19-30 y, and decreased to approximately 66 +/- 17 g/d in the elderly. The percentage of the male population who consumed less than the estimated average requirement was very low. Our estimates indicated that 7.7% of adolescent females and 7.2-8.6% of older adult women reported consuming protein levels below their estimated average requirement. The median intake of protein on a percentage of calories basis ranged from 13.4% in children aged 4-8 y to 16.0% in men aged 51-70 y. Even the 95th percentile of protein intake did not approach the highest acceptable macronutrient distribution range of 35% for an age/sex group. The highest 95th percentile of protein intake was 20.8% of calories in men aged 51-70 y. Given the demonstrated benefits of higher protein intake on weight management, sarcopenia, and other physiologic functions, efforts should be undertaken to ensure that Americans consume the recommended amount of protein (17-21% of calories as expected from MyPyramid food patterns).