WWEIA data are collected using USDA’s dietary data collection instrument, the Automated Multiple-Pass Method (AMPM). The AMPM is a fully computerized method for collecting 24-hour dietary recalls either in person or by telephone. In this multiple-pass method, information is collected by 5 standardized steps. The AMPM is a research-based approach designed to enhance efficient collection of complete and accurate food intake data in large-scale national surveys and reduce respondent burden. The AMPM is updated yearly to reflect the changing food supply

The AMPM collects a list of all foods and beverages consumed in a 24-hour period. Information captured by AMPM includes:

• For each food... 
      - Description of food 
      - Additions to the food (for example, milk on cereal or cream in coffee)
      - Combination code that identifies foods eaten together 
        (such as milk added to cereal)
      - Amount of food consumed
      - Time eaten 
      - Name of eating occasion 
      - Where obtained 
      - Eaten at home or not 
   
• Water consumption - bottled and tap water
   
• Use of salt in preparing foods and at the table 
   
• Whether the amount of food consumed on the recall day was much more than usual, usual, or much less than usual 
   
• Currently on a diet to lose weight or some other health-related reason