Objective: To describe the sources of protein intake in a sample of the US adult population and among subgroups defined by race-ethnicity, age, and gender.
Design: The Third National Health and Nutrition Examination Survey, 1988-1991, is a stratified random sample of the total civilian noninstitutionalized population, drawn from the 50 United States and the District of Columbia. For all foods consumed by the participants, based on a 24-hour dietary recall, protein sources and the contribution of each protein type to the total protein intake were determined.
Subjects: Adult participants in the third National Health and Nutrition Examination Survey (n = 7,924).
Statistical analyses: Weighted total, age-specific, and age-adjusted mean protein intakes were calculated using SAS and WesVarPC. Statistical differences were determined by 2-tailed t tests.
Results: The main protein source in the American diet is animal protein (69%). Meat, fish, and poultry protein combined contributed the most to animal protein (42%), followed by dairy protein (20%). Grains (18%) contributed the most to plant protein consumption. Women consumed a lower percentage of beef (14%) and pork (7%) protein than did men (18% and 9%, respectively). Women also consumed a higher percentage of poultry (13%), dairy (22%), and fruit and vegetable (11%) protein than did men (11%, 19%, and 9%, respectively). Blacks reported eating a higher percentage of poultry (18%) and pork (11%) protein and a lower percent of dairy protein (14%) than did whites (12%, 7%, and 22%, respectively) and Mexican-Americans (11%, 8%, and 17%, respectively). Mexican-Americans consumed a higher percentage of legume (7%) and egg (7%) protein than did whites (4% and 4%, respectively) and blacks (4% and 5%, respectively). Whites consumed a higher percentage of grain protein (19%) than did blacks (16%) and Mexican-Americans (15%).
Conclusions: These results show that, although the percentage of total energy from protein may be similar among race-ethnicities and between men and women, their sources of protein are different. These differences should be taken into account when providing nutrition education for specific populations.