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United States Department of Agriculture

Agricultural Research Service

WWEIA/NHANES 2005-2006
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Intake Days


Two days of dietary intake data are available. 

  • Day 1 is collected in person in the Mobile Examination Center. The Day 1 files include:
    • 9,169 individuals with a complete intake
    • 180 breastfed infants
  • Day 2 is collected by telephone 3 to 10 days later. The Day 2 files include:
    • 8,264 individuals with a complete intake
    • 165 breastfed infants

Data File Descriptions


Four dietary intake files are available.

  • Individual Foods Files:  DR1IFF_D (Day 1) and DR2IFF_D (Day 2)
    The Individual Foods Files include, for each interview day, one record for each food consumed by a participant.  Each record identifies the intake day of week, the time and name of the eating occasion for the food, and the following food-specific data:

    • Food, identified by a USDA food code
    • Whether food was eaten in combination with other foods (for example, milk added to cereal)
    • Amount of food consumed
    • Amounts of food energy and 63 nutrients/food components provided by the food amount
  • Total Nutrient Intakes Files:  DR1TOT_D (Day 1) and DR2IFF_D (Day 2)
    The Total Nutrient Intakes Files contain, for each interview day, one record for each participant. Each record includes daily total intakes of food energy and 63 nutrients/food components, daily intake of water, and whether the amount of food consumed was usual, much more than usual, or much less than usual. The Day 1 file also includes information on salt use, whether the participant is on a special diet (weight loss, low carbohydrate, etc.), and  frequency of fish and shellfish consumption for population subsets. 

Sampling Weights


  • Sampling weights specific to the dietary intake data adjust for over-representation of weekend days.
  • Two sets of weights-Day 1 weights (WTDRD1) are applied to Day 1 data; two-day weights (WTDR2D) are applied when both days are used (Day 1 and Day 2).
  • Read about the dietary intake sampling weights (page 14).

Last Modified: 10/4/2016
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