Food frequency questionnaire

Food frequency questionnaire (FFQ) is a commonly used dietary assessment tool in epidemiological studies and nutritional epidemiology. It is a method for assessing dietary intake by asking individuals how often they consume specific foods and beverages over a given period of time, typically the past year.

Overview

The Food frequency questionnaire is a retrospective, self-administered dietary assessment instrument that asks about frequency of consumption and portion size of a list of foods and beverages. The list of foods and beverages included in the FFQ is usually based on the common foods consumed in the population of interest. The FFQ is designed to capture long-term dietary intake, and is therefore most often used to assess diet-disease relationships in epidemiological studies.

Methodology

The FFQ typically includes a list of foods and beverages, with options for frequency of consumption and portion size. The frequency options usually range from "never or less than once per month" to "6+ times per day". The portion size options are usually based on standard serving sizes for each food or beverage. The responses are then converted into daily intake estimates for each food and beverage, and these estimates are used to calculate nutrient intake.

Limitations

While the FFQ is a valuable tool in nutritional epidemiology, it has several limitations. These include reliance on memory, difficulty in estimating portion sizes, and potential for bias due to social desirability or underreporting. In addition, the FFQ may not capture all foods and beverages consumed, particularly those that are not commonly consumed in the population of interest.

Validation

Validation of the FFQ is important to ensure that it accurately measures dietary intake. This is typically done by comparing the FFQ to a more detailed dietary assessment method, such as a 24-hour dietary recall or a dietary record. The degree of agreement between the two methods is then assessed.

Use in Research

The FFQ is widely used in epidemiological studies to assess diet-disease relationships. It has been used to study the relationship between diet and a variety of diseases, including cardiovascular disease, cancer, and diabetes.

See Also

• 24-hour dietary recall
• Dietary record
• Nutritional epidemiology
• Dietary assessment