The aim of this report is to describe INTERMAP standardized procedures for assessing dietary intake of 4680 individuals from 17 population samples in China, Japan, UK and USA: Based on a common Protocol and Manuals of Operations, standardized collection by centrally trained certified staff of four 24 h dietary recalls, two timed 24-h urines, two 7-day histories of daily alcohol intake per participant; tape recording of all dietary interviews, and use of multiple methods for ongoing quality control of dietary data collection and processing (local, national, and international); one central laboratory for urine analyses; review, update, expansion of available databases for four countries to produce comparable data on 76 nutrients for all reported foods; use of these databases at international coordinating centres to compute nutrient composition. Chinese participants reported 2257 foods; Japanese, 2931; and UK, 3963. In US, use was made of 17 000 food items in the online automated Nutrition Data System. Average time/ recall ranged from 22 min for China to 31 min for UK. Among indicators of dietary data quality, coding error rates (from recoding 10% random samples of recalls) were 2.3% for China, 1.4% for Japan, and UK; an analogous US procedure (re-entry of recalls into computer from tape recordings) also yielded low discrepancy rates. Average scores on assessment of taped dietary interviews were high, 40.4 (Japan) to 45.3 (China) (highest possible score: 48); correlations between urinary and dietary nutrient valuesFsimilar for men and womenF were, for all 4680 participants, 0.51 for total protein, range across countries 0.40-0.52; 0.55 for potassium, range 0.30-0.58; 0.42 for sodium, range 0.33-0.46. The updated dietary databases are valuable international resources. Dietary quality control procedures yielded data generally indicative of high quality performance in the four countries. These procedures were time consuming. Ongoing recoding of random samples of recalls is deemed essential. Use of tape recorded dietary interviews contributed to quality control, despite feasibility problems, deemed remediable by protocol modification. For quality assessment, use of correlation data on dietary and urinary nutrient values yielded meaningful findings, including evidence of special difficulties in assessing sodium intake by dietary methods.

In nutritional epidemiology, it is often assumed that nutrient absorption is proportional to nutrient intake. For several nutrients, including non-haem Fe, this assumption may not hold. Depending on the nutrients ingested with non-haem Fe, its availability for absorption varies greatly. Therefore, using Fe intake to examine associations between Fe and health can impact upon the validity of findings. Previous algorithms that adjust Fe intakes for dietary factors known to affect absorption have been found to underestimate Fe absorption and, in the present study, perform poorly on independent dietary data. We have designed a new algorithm to adjust Fe intakes for the effects of ascorbic acid, meat, fish and poultry, phytate, polyphenols and Ca, incorporating not only absorption data from test meals but also current understanding of Fe absorption. In so doing, we have created a robust and universal Fe algorithm with potential for use in large cohorts. The algorithm described aims not to predict Fe absorption but available Fe in the gut, a measure we believe to be of greater use in epidemiological research. Available Fe is Fe available for absorption from the gastrointestinal tract, taking into account enhancing or inhibiting effects of dietary modifiers. Our algorithm successfully estimated average Fe availability in test meal data used to construct the algorithm and, unlike other algorithms tested, also provided plausible predictions when applied to independent dietary data. Future research is needed to evaluate the extent to which this algorithm is useful in epidemiological research to relate Fe to health outcomes.

Erythrocyte incorporation of isotopic iron (Fe) is the standard method for assessing iron bioavailability, but the process is expensive, technically difficult, and gives no information on the kinetics of absorption. The main objective of this study was to validate serum Fe curves as measures of dietary iron absorption because previous work demonstrated that serum iron curves can be generated with iron doses as low as 5-20 mg and that up to 20 mg iron can be added to meals without affecting relative absorption. In 3 studies, groups (n = 10, 10, 21) of Fe-deficient, mildly anemic women consumed meals of varying calculated Fe bioavailability, with and without added ferric chloride (10 mg Fe). Blood samples were collected at baseline and every 30 min for 4 h after the meal. Serum Fe concentrations were measured. Areas under the serum Fe curves and peak concentrations were used in different models to estimate Fe absorption and uptake. In 21 subjects, (58)Fe-enriched ferric chloride was added to the meals, and blood was taken 2 wk later to calculate red cell isotope incorporation. The addition of 10 mg Fe to test meals produced measurable serum iron curves even when the meal Fe bioavailability was low. Serum Fe curves were highly reproducible and were affected as expected by food composition. Even the single measurement at the estimated time of peak iron concentration was correlated significantly with erythrocyte incorporation of (58)Fe (r = 0.72, P < 0.0001). Hence the extent and rate of absorption of nonheme iron from meals, rather than in individuals, can be investigated with such subjects without the need for isotopes.

The International Study of Macronutrients and Blood Pressure (INTERMAP) is a four-country study investigating relationships between individual dietary intakes and blood pressure. Dietary intake patterns of individuals were estimated for macronutrients (proteins, lipids, carbohydrates, alcohol) and their components (amino acids, fatty acids, starch), as well as minerals, vitamins, caffeine, and dietary fiber. The dietary assessment phase of the study involved collection of four 24-h recalls and two 24-h urine specimens from each of 4680 adults, ages 40-59, at 16 centers located in the People's Republic of China, Japan, the United Kingdom and the United States.

Objectives: To explore dietary intake and weight gain during pregnancy in relation to dietary restraint. Design: Longitudinal prospective study. Attitudes to weight gain during pregnancy were assessed using selfadministered questionnaires and dietary intake by 7-d weighed diet records in early and late pregnancy. Setting: South West London 1995 ± 1996. Subjects: 74 Caucasian pregnant women expecting their ®rst or second baby were recruited through a London hospital and data from 62 women were analysed. Results: Restrained eaters were signi®cantly less likely to experience weight gains within the recommended range for their pre-pregnancy body mass index (BMI) (P 0.026). They gained either more or less weight than recommended. Conclusions: Dietary restraint appears to have undesirable in¯uences on eating and weight gain during pregnancy which require further attention. Sponsorship: South Bank University and Cow and Gate Nutricia Ltd. provided ®nancial assistance for this project.

Coding diet records is a basic element of most dietary surveys, yet it often receives little attention even though errors in coding can lead to flawed study results. In the INTERnational study of MAcro-and micronutrients and blood Pressure (INTERMAP study), efforts were made to minimise errors in coding the 18 720 diet records. Staff were centrally trained and certified before being able to process study data and ongoing quality control checks were performed. This involved the senior (site) nutritionist re-coding randomly selected diet records. To facilitate standardisation of coding in the UK, a code book was designed; it included information about coding brand items, density and portion size information, and default codes to be assigned when limited information was available for food items. It was found that trainees, despite previous experience in coding elsewhere, made coding errors that resulted in errors in estimates of daily energy and nutrient intakes. As training proceeded, the number of errors decreased. Compilation of the code book was labour-intensive, as information from food manufacturers and retailers had to be collected. Strategies are required to avoid repetition of this effort by other research groups. While the methods used in INTERMAP to reduce coding errors were time consuming, the experiences suggest that such errors are important and that they can be reduced.

Collection of complete and accurate dietary intake data is necessary to investigate the association of nutrient intakes with disease outcomes. A standardised multiple-pass 24 h dietary recall method was used in the International Collaborative Study of Macro-and Micronutrients and Blood Pressure (INTERMAP) to obtain maximally objective data. Dietary interviewers were intensively trained and recalls taped, with consent, for randomly selected evaluations by the local site nutritionist (SN) and/or country nutritionists (CN) using a twelve-criterion checklist marked on a four-point scale (1, retrain, to 4, excellent). In the Belfast centre, seven dietary interviewers collected 932 24 h recalls from 40-59-year-old men and women. Total scores from the 134 evaluated recalls ranged from thirty-four to the maximum forty-eight points. All twelve aspects of the interviews were completed satisfactorily on average whether scored by the SN (n 53, range: probing 3·25 to privacy of interview 3·98) or CN (n 19, range: probing 3·26 to pace of interview and general manner of interviewer 3·95); the CN gave significantly lower scores than the SN for recalls evaluated by both nutritionists (n 31, Wilcoxon signed rank test, P¼0·001). Five evaluations of three recalls identified areas requiring retraining or work to improve performance. Reporting accuracy was estimated using BMR; energy intake estimates less than 1·2 £ BMR identifying under-reporting. Mean ratios in all age, sex and body-mass groups were above this cut-off point; overall, 26·1 % were below. Experiences from the INTERMAP Belfast centre indicate that difficulties in collection of dietary information can be anticipated and contained by the systematic use of methods to prevent, detect and correct errors.

Background Dietary supplements (DSs) are not recommended for the prevention of cancer recurrence. Although DS use is common in individuals living with and beyond cancer, its associations with beliefs about reduced cancer recurrence risk and demographic and health behaviors are unclear. Methods Adults (18 years old or older) who had been diagnosed with breast, prostate, or colorectal cancer were recruited through National Health Service sites in Essex and London. Participants completed a mailed survey and telephone or online 24‐hour dietary recalls (MyFood24). Supplement use was collected during the dietary recalls. Associations between DS use and demographics, health behaviors, and beliefs about DSs and cancer were explored. Results Nineteen percent of 1049 individuals believed that DSs were important for the reduction of cancer recurrence risk, and 40% of individuals reported DS use. DS use was positively associated with being female (odds ratio [OR], 2.48; confidence interval [CI], 1.72‐3.56), meeting 5‐a‐day fruit and vegetable recommendations (OR, 1.36; CI, 1.02‐1.82), and believing that DSs were important for reducing cancer recurrence risk (OR, 3.13; CI, 2.35‐4.18). DS use was negatively associated with having obesity (OR, 0.58; CI, 0.38‐0.87). The most commonly taken DSs overall were fish oils (taken by 13%). Calcium with or without vitamin D was the most common DS taken by individuals with breast cancer (15%). Conclusions DS use by individuals living with and beyond cancer is associated with demographic factors and health behaviors. A belief that DSs reduce the risk of cancer recurrence is common and positively associated with DS use. There is a need for health care professionals to provide advice about DS use and cancer recurrence risk.