A Comparison of Dietary Methods in Epidemiologic Studies1

Abstract

Three methods of estimating group and individual dietary consumption have been developed and assessed in a case-control study of diet and breast cancer. The methods comprised a 24-hour recall, a detailed quantitative diet history directed to the most recent two-month period and the two-month period six months before, and a four-day diet diary. There is a high degree of correlation between the estimates of food consumption for the controls using each of the methods. The highest estimate was obtained from the diet history, with a slightly higher estimate in the period six months before than the current period, while the lowest is found in the 24-hour recall. The latter corresponds with the same method in a Nutrition Canada Survey. It is concluded that all methods ara applicable to case-control studies, but the diet history is preferred when current food intake may be influenced by a disease.

Factors affecting iron stores in infants 4–18 months of age

“…The agreement was better at 8 than 18 months, re¯ecting the fact that by 18 months a more varied diet has been introduced. It is generally accepted that weighed intakes and duplicate diet collections tend to underestimate habitual intake, whereas the 24 h recall overestimates habitual intake (Morgan et al, 1978). Diet histories fall somewhere in between, and therefore give more representative estimates of nutrient intake, particularly for groups consuming a restricted variety of foods, as is the case with infants.…”

“…The dietary intake of the infants was obtained from diet history data (Morgan et al, 1978) in which a standardised equation sheet was used by the interviewer (Table 1). This ful®lled the criteria listed by Marr (1971) in that it was comprised of an assessment of the overall pattern of eating, coupled with 24 h recall.…”

Determinants and nature of dietary underreporting in a free-living population: the Fleurbaix Laventie Ville Santé (FLVS) study

“…Using a cutoff value over 1.55 would lead to the exclusion of too many subjects, thus, to minimize bias we used the lowest cut-off that might reasonably exclude the major under-reporters, Using the same cut-off limit as in our study, Ballard-Barbash 22 reported higher levels of severe underreporting, which could be explained by his method of dietary assessment: four repeated 24 h recalls. Such 24 h recalls rely on memory and have been shown to give lower estimates of food intake than three-or four-day records, 30,31 leading to a higher proportion of underreporting. Using a seven-day weighed food record and the same methodology as us to identify underreporters in young adults, Haraldsdottir et al 25 found a similar frequency of underreporting, especially in men (18%).…”

Glycaemic index, glycaemic load and ovarian cancer risk: a prospective cohort study

“…Calculation of nutrient intake, overall glycaemic index and glycaemic load Data from the completed self-administered FFQs were used to estimate daily intake of nutrients using a database for Canadian foods that has been described elsewhere 25 . Data from the FFQ were also used to estimate overall GI and GL.…”