The aim of this study was to identify the food sources of protein and 18 amino acids (AAs) in the average Polish diet. The analysis was conducted based on the 2016 Household Budget Survey (HBS) on the consumption of food products from a representative sample of 38,886 households (n = 99,230). This survey was organized, conducted and controlled by the Central Statistical Office, Social Surveys and Living Conditions Statistics Department in cooperation with the Statistic Office in Łódź based on the recording of expenditures, quantitative consumption, and revenues in budget books for one month. 91 food products from 13 food categories (e.g., meat and meat products, grain products) consisting of 42 food groups (e.g., red meat, milk, cheese) were analyzed to determine protein and amino acid intake from these products. Three categories delivered 80.9% of total protein (meat and meat products: 38.9%; grain products: 23.9%; and milk and dairy products: 18.1%). The branched-chain amino acids (BCAAs: leucine, isoleucine and valine) were delivered mainly by meat and meat products (39.9%; 41.3% and 37.4%, respectively). Meat and meat products were also the most important source for other essential amino acids (EAAs: lysine 49.2%, histidine 46.6%, threonine 44.7%, tryptophan 41.4%, phenylalanine 35.3%, and methionine 44.2%). In terms of the contribution of the non-essential or conditionally essential amino acids to the average Polish diet, most important were grain products (for cysteine: 41.2%; glutamic acid: 33.8%; proline: 34.1%), and meat and meat products (for tyrosine: 38.3%; arginine: 46.1%; alanine: 48.7%; aspartic acid: 41.7%; glycine: 52.5%; serine: 33.6%). Five clusters were identified to assess the impact of socio-demographic and economic factors on the protein supply. The largest impact was observed for respondent education, degree of urbanization, study month, and usage of agricultural land. The shares of animal food in total protein supply amounted to 66.5% in total population and varied from 56.4% to 73.6% in different clusters.
Keywords: amino acids food sources; protein; protein food sources.