Dietary intake methodology I. USDA surveys and supporting research

Area of Science:

• Nutrition Science
• Public Health
• Agricultural Economics

Background:

• The U.S. Department of Agriculture (USDA) has conducted nationwide food consumption surveys every ~10 years since the 1930s.
• These surveys are crucial for informing policies on food production, safety, assistance, and nutrition education.
• Survey methodologies evolved from household consumption to individual food intakes, with continuous smaller surveys since 1985.

Purpose of the Study:

• To monitor national dietary patterns and inform public policy.
• To improve the methodologies used in surveying individuals' dietary intakes.
• To adapt survey methods to capture day-to-day dietary variations.

Main Methods:

• Utilized decennial surveys and smaller, continuous surveys of food intake.
• Employed 1-day recalls, 3-day recalls, and 2-day food records.
• Conducted extensive research since 1975 to refine survey techniques, including validation studies and respondent debriefings.

Main Results:

• Survey scope expanded from household to individual food consumption.
• Methodological improvements have been incorporated into current survey procedures.
• Research tested various recall and diary methods, validation approaches, and contact methods (in-person, telephone, mail).

Conclusions:

• USDA dietary surveys are essential for understanding and guiding national nutrition and food policies.
• Continuous methodological research has enhanced the accuracy and scope of dietary intake data collection.
• The evolution of survey methods ensures more comprehensive monitoring of the nation's dietary patterns.