Food Frequency Questionnaire Overview

Food Frequency Questionnaire (FFQ)

• A tool assessing how often a person consumes specific foods.
• Food lists tailored to the target population.
• Accounts for major food and nutrient sources within the population.
• Usually lists 150 foods or fewer.
• Frequency measured in days, weeks, months, or years.
• Sometimes, typical portion sizes are estimated.
• Respondents record answers on a machine-readable form.
• Useful for assessing dietary patterns and intakes
• FFQs often target certain nutrients for screening.
• FFQs are commonly used as a screener for calcium, fat, fruit, vegetables, and fiber.

Different FFQ Formats

• Simple (nonquantitative):

  • Measures average use over the year in terms of frequency categories (e.g., never, less than 1/month, 1-3/month, etc.).
  • Provides a basic understanding of food consumption patterns.

• Semiquantitative:

  • Measures average use over the past year, broken down by frequency categories.
  • Quantifies the amounts consumed (e.g., 1 cup, 1/2 cup coffee).

• Quantitative:

  • Measures average use across different frequency categories and quantifies intake using specific portions.
  • Provides more precise details about consumption frequency and quantity.

Food Frequency Questionnaire (FFQ) Development

• Target a research question: Establish clear aim.
• Define target population. Specify characteristics of the people being observed.
• Choose data type: Decide if you need general foods/nutrients or specific ones.
• Use 24-hour recalls from the population sample: (500-1000 individuals).
• Eliminate foods reported by few: Keep the list focused on common foods.
• Select foods that explain the most variation: Focus on foods contributing most to dietary intake differences.

Strengths and Limitations of FFQs

• Strengths: Quick, inexpensive, often automatically processable, good reliability.
• Limitations: Questionable validity, underreporting of energy intakes, foods and portions need close consideration.

Alternative Diet Assessment Methods

• Diet History:

  • Assess general health habits as well as usual eating patterns through interviews.
  • May use a food record as a part of the assessment.
  • Strengths includes capturing holistic eating patterns.
  • Limitations include time constraints, time commitment and reliance on trained interviewers' judgment.

• Duplicate food collection:

  • Participants collect identical meals and researchers analyze them in a laboratory;
  • Strengths : High accuracy, and participants are aware it is a representative diet.
  • Limitations: Requires extra effort, food waste, and participant reactivity.

• Food accounts:

  • Collect data from households or institutions analyzing disappearance.
  • Strengths include long periods of observation and broad-scale data.
  • Limitations include focus on trends not individual data.

• Telephone interviewing:

  • Provides efficient data collection for recall, often serves as a complement to face-to-face interactions.
  • Strengths relates to cost effectiveness, limited logistical hurdles, and security.
  • Limitations include reduced number of landline phones and potential difficulty in accurately obtaining portion sizes.

• Technological Improvements:

  • Modern FFQs incorporating digital imaging and use of cell phones or wearable technology, allowing improved accuracy and efficiency. -Strengths include lower burden, greater validity, reduced reactivity.
  • Limitations relate to cost, photo quality, and issues with similar-appearing food items.

Additional Information

• A food frequency questionnaire (FFQ) is a dietary assessment instrument.
• FFQs capture typical dietary intake over a defined period (usually the past year).
• Information from FFQs will often target a specific nutrient or intake to give information to a research area.
• Several methods exist to assess diets, each having advantages and disadvantages.
• Choosing the most suitable method depends on the specific research question, resources, and limitations.