A validation study on food composition tables for the international cooperative INTERMAP study in Japan

The INTERMAP Study is an international cooperative study on the relationship between macro- and micro-nutrient intakes and blood pressure. The present study-ancillary to INTERMAP-is to evaluate validity of the INTERMAP Tables of Food Composition in Japan (ITJ) formulated by modifying the Standard Tables of Food Composition in Japan (STJ), including factoring in changes in weight and nutrient composition of individual foods due to cooking.

With chemical analytical values of 96 meals prepared in two university hospitals in Japan as the "gold standard", validity of calculated values based on the ITJ was examined for six major components (energy, protein, lipid, carbohydrate, sodium, potassium) by comparison of mean values, correlation, and linear regression analysis.

Although both the ITJ-based and STJ-based calculated values for all six components were significantly higher than the analytical values, differences from the analytical values were generally less marked for the ITJ-based values than for the STJ-based values. The STJ-based values were significantly higher than the ITJ-based values for protein and potassium. Analytical values showed slightly stronger correlations with the ITJ-based calculated values (r=0.876 for total energy, r=0.789 for lipid, r=0.832 for potassium) than with the STJ-based calculated values, except for carbohydrates.

The ITJ was considered to have greater validity than the STJ. To obtain more accaurate data in nutritional surveys, food composition tables in which changes in nutrient compositions due to cooking methods are taken into consideration should be used.