Radioactivity levels in 137 foods commonly consumed daily in Japan were evaluated to determine the committed effective dose in the Japanese adults. The levels of radioactivity for ²³⁸U, ²³²Th, ²²⁶Ra, ²¹⁰Pb, ²¹⁰Po, ⁹⁰Sr, ¹³⁷Cs and ^239+240Pu were ND-5.2 Bq/kg fresh weight, ND-0.18 Bq/kg fresh weight, ND-3.9Bq/kg fresh weight, ND-45 Bq/kg fresh weight, ND-120 Bq/kg fresh weight, ND-9.9 Bq/kg fresh weight, ND-19 Bq/kg fresh weight and ND-0.010 Bq/kg fresh weight, respectively. The committed effective dose was estimated to be 0.80 mSv from the intake of the foods. The effective dose was greater than the world mean value for adults of 0.12 mSv by natural radioactive elements in the uranium and thorium series from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000 because of the large contribution from ²¹⁰Po in seafood.