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.
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.
Adult participants in the third National Health and Nutrition Examination Survey (n = 7,924).
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.
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%).
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.