among the subsample,a 24-hour dietary recall,which included a weighing of condiments in the household,was administered,and a 24-hour urine sample was collected.(at the same time the urine was collected, a fasting blood sample was also collected, but the results of these blood samples will be published elsewhere.) The 24-hour dietary recall took place during 3 consecutive days, usually thursday,Friday, and Saturday(9). Trained health staff visited each selected household and weighed all condiments (ie,salt,low-sodium saft,soy sauce,monosodium glutamate,vinegar,chicken essential,bean sauce, sweet flour sauce,chili sauce,and shrimp sauce) directly at the start of the first 24-hour dietary recall and at the end of the last 24-hour dietary recall. Each selected household was asked to record the purchase or spillage(or other wastage) of any condiments during the survey days and report these to the health staff during their final visit. Individuals were trained to record their entire food diary every day into the a standardized table and report the portion of each item consumed. The total individual dietary sodium intake was the combination of sodium estimated from condiments and the dietary recall. we used the sodium reference values from china food composition table 2004(10) to calculate the sodium content for all condiments and foods.