Virtually all epidemiologists (including us) who have investigated relationships between diet and chronic disease in the past 20 years have used food frequency questionnaires (FFQ) to assess diet and will continue to publish findings based on FFQ-derived data. However, in our editorial ‘‘Is it Time to Abandon the Food Frequency Questionnaire,’’ we addressed how we should conduct epidemiologic s...

OBJECTIVE To illustrate the impact of intake-related bias in FFQ and 24 h recall (24hR), and correlated errors between these methods, on intake-health associations. DESIGN Dietary intake was assessed by a 180-item semi-quantitative FFQ and two 24hR. Urinary N and urinary K were estimated from two 24 h urine samples. We compared four scenarios to correct associations for errors in an FFQ estim...

BACKGROUND Food frequency questionnaires (FFQ) are used for epidemiological studies. Because of the wide variations in dietary habits within different populations, a FFQ must be developed to suit the specific group. To date, no FFQ has been developed for Japanese children. In this study, we developed a FFQ to assess the regular dietary intake of Japanese children. The FFQ included questions reg...

We investigated the relative validity of an interview-administered FFQ to estimate phytoestrogen intake among South Asian women in the UK. A population-based sample of 108 healthy South Asian women completed random repeated monthly 24-h recalls [with a subsample (n 58) also providing multiple plasma samples] over a period of 1 y followed by administration of the FFQ. The FFQ produced slightly h...

OBJECTIVE To determine the relative validity of a quantitative FFQ in assessing dietary fluoride intakes using 3 d food and beverage diaries for reference. DESIGN Parents were asked to complete questionnaires for the preceding week and diaries for 3 d for their children. Fluoride intakes were estimated from 'selected' foods and beverages for questionnaires and from 'all foods and beverages' f...

OBJECTIVE For proper interpretation of results from epidemiological studies that use food-frequency questionnaires (FFQs), it is necessary to know the relationship between reported intakes from the FFQ and true usual intake. In this paper, we report a calibration study conducted to investigate the performance of the FFQ used in a cohort study, the Canadian Study of Diet, Lifestyle and Health. ...

OBJECTIVE The aim of this study was to evaluate a short food frequency questionnaire (FFQ) against a four-day precoded food diary (PFD) with regard to frequency of food intake among Norwegian 9- and 13-year-olds. SUBJECTS AND DESIGN A total of 733 9-year-olds and 904 13-year-olds completed first a short FFQ and one to two weeks later a four-day PFD. The short FFQ included questions about 23 f...

The Dutch Healthy Diet index (DHD-index) was developed using data from two 24 h recalls (24hR) and appeared useful to evaluate diet quality in Dutch adults. As many epidemiologic studies use FFQ, we now estimated the DHD-index score using FFQ data. We compared whether this score showed similar associations with participants' characteristics, micronutrient intakes, and biomarkers of intake and m...

BACKGROUND We have developed a food frequency questionnaire (FFQ) for the assessment of habitual diet, with special focus on the intake of fruit, vegetables and other antioxidant-rich foods and beverages. The aim of the present study was to evaluate the relative validity of the intakes of energy, food and nutrients from the FFQ. METHODS Energy intake was evaluated against independent measures...