Estimation of nutrient intake by the new version of Japanese food composition tables in comparison with that by the previous version

Applicability of food composition tables as a tool to estimate mineral and trace element intake of pre-school children in Japan: a validation study

Because dietary intakes of some minerals (including trace elements), especially iron (Fe), are insufficient for the needs of the general Japanese population, accurate estimation of mineral intake is important. This capability is especially necessary to preserve the health of Japanese children. Therefore, the current version of food composition tables (FCT) in Japan was evaluated for validity as tools to estimate dietary intake of minerals for children. For this purpose, 24h food duplicate samples were collected from 292 pre-school children in Miyagi prefecture, Japan. From the weights of items and food codes, intakes of nine minerals were estimated taking advantage of the FCT. In parallel, amounts of minerals in each duplicate samples were instrumentally measured by ICP-AES for Ca, Cu, Fe, Mg, Mn, P and Zn, and by flame AAS for K and Na, both after wet-ashing. The distributions of the mineral amounts were essentially normal. The comparison of the FCT-based estimates (E) and instrumental measures (M) showed that the E/M ratio was close to 1 for Ca, K, Mn, P and Zn, suggesting that E may be a surrogate of M for Ca, K, Mn, P and Zn on a group basis. The ratio being larger than 1.2 for Cu, Fe, Mg and Na indicates that a risk of over-estimation exists when E is relied upon in place of M. On an individual basis, significant differences were detected for all 9 minerals suggesting that the use of E as a surrogate for M should be practiced with care for the estimation of mineral intake.

Dietary tin intake and association with canned food consumption in Japanese preschool children

OBJECTIVES

Dietary intake of tin has seldom been studied in children although they probably have a high intake. This study was initiated to investigate dietary tin intake (Sn-D) of children in Japan.

METHODS

In this study, 24-h food duplicate samples were collected from 296 preschool children in Miyagi prefecture, Japan. Sn in the samples were analyzed by inductively coupled-plasma mass spectrometry, after homogenization and wet digestion.

RESULTS

Sn-D by the children was low, with 4.2 μg/day as a median. The distribution was however wide, from 0.4 μg/day up to >3 μg/day. Canned foods were the major dietary Sn source, whereas rice contributed essentially little. Sn-D among canned food consumers was 30.2 μg/day as a geometric mean (10.6 μg/day as a median), whereas Sn-D among the non-consumers of canned foods was distributed log-normally, with 3.3 μg/day as a geometric mean (2.5 μg/day as a median). Sn levels in urine did not differ between children who consumed canned foods on the day previous to urine collection and those who did not. The Sn-D was far below the provisional tolerable weekly intake (14 mg/kg body weight/week) set by the 2001 Joint FAO/WHO Expert Committee. Nevertheless, children took more Sn than adults when compared on a body-weight basis.

CONCLUSIONS

Canned foods were the major source of dietary Sn intake for preschool children studied. Thus, median Sn-D was higher for the canned food consumers (10.6 μg/day) than for non-consumers of canned foods (2.5 μg/day). Sn-D by canned food-consuming children was, however, substantially lower than the provisional tolerable weekly intake. No difference was detected in Sn levels in urine between canned food-consuming and non-consuming children.

Reduction in estimated vitamin A intake induced by new food composition tables in Japan, where vitamin A is taken mostly from plant foods

A revised edition of the standard tables of food composition was implemented in Japan in 2005; one of the major revision points is the change of retinol activity equivalents for pro-vitamin A carotenoids. This preliminary analysis was conducted to examine whether the revision affects the estimation of vitamin A intake; and if so, to what extent. Accordingly, a field survey was conducted to collect 24-h duplicates of daily foods of citizens, and 26 adult women volunteered. Application of the procedures in the new and previous standard tables of food composition gave 537 microg retinol activity equivalent and 704 microg retinol equivalence, respectively, for daily vitamin A intake. Thus, the changes in retinol activity equivalents induced substantial reduction (by 24%) in estimation of vitamin A intake among the Japanese population, for whom pro-vitamin A carotenoids in plant foods are the major sources (76%) for vitamin A, and retinol accounts for only 35% (on the retinol activity equivalent basis).

Limited acceptance of globalization in food habits among middle-aged women in Osaka, Japan

The study was initiated to identify the effects of recent changes in dietary pattern in Japan on nutrient intake. In the large city of Osaka, Japan, 24-h food duplicate samples were collected from 26 middle-aged women, and nutrients in the duplicates were estimated in reference to standard tables of food composition. The subjects took 1844 kcal (7.72 MJ) energy, 67.5 g protein, and 54.5 g lipid (37% from plants) per day. Micro-nutrient intakes were generally sufficient, but NaCl intake tended to be excessive, and the relatively high body mass index (>25 in six cases) suggested a possibility of over-eating. The food composition was rich in rice and fish, being basically of a traditional type. Consumption of bread, an acquired habit, was observed in 65% of the breakfasts but less so in lunch and none in dinner. Thus, the acceptance of bread in place of rice was limited and did not induce substantial alteration in nutrient intakes.

Dietary intake of tin in Japan, and the effects on intake of canned food and beverage consumption

The study reported herein was initiated to examine dietary tin intake (Sn-D) in Japan to elucidate the possible effects of consumption of canned food (including beverages) on Sn-D, and to compare the intake among regions and between the two sexes in reference to the current provisional tolerable weekly intake and intake in other countries. Urinary tin levels (Sn-U) were also studied. Duplicate diet samples (24 h) together with records of food intake were collected in 1999-2004 from 111 adult residents in four areas of Japan. After exclusion of incomplete samples, 95 valid samples were subjected to determination of tin by inductively coupled plasma mass spectrometry (ICP-MS) after acid digestion. Among the 95 cases, 37 women additionally provided urine samples. Distribution of Sn-D was markedly skewed. Median Sn-D was 5.6 microg day(-1) for total subjects, which was about one-tenth of the values previously reported for the Japanese population; the difference was most probably attributable to the difference in the methods of determination. Consumption of canned foods led to a substantial increase in Sn-D. Thus, the median Sn-D for canned food consumers of 35.7 microg day(-1), was eight-fold higher than the median Sn-D for non-consumers of 4.5 microg day(-1). Sn-U (as corrected for creatinine concentration) distributed log-normally with a geometric mean of 2.0 microg (g cr)(-1). No effect of canned food consumption was evident on Sn-U. When compared internationally, Sn-D for the Japanese population was substantially lower than Sn-D for populations in other industrialized countries.

Impact of the revision of a nutrient database on the validity of a self-administered food frequency questionnaire (FFQ)

BACKGROUND

Revision of the national nutrient database in 2000 had a strong impact on the absolute level of estimated nutrient intake in dietary assessments. However, whether it influenced the ranking of individuals by estimated intake, a more important function in epidemiologic studies, has not been investigated. Here, we investigated the effect of this revision of the nutrient database on the validity of a food frequency questionnaire (FFQ) used to estimate nutrient intake in the Japan Public Health Center-based prospective Study (JPHC Study).

METHODS

Subjects were a subsample of the JPHC Study who volunteered to participate in the validation study of the FFQ. Validity of the FFQ was evaluated by reference to the 28-day weighed dietary records as a gold standard. Nutrient intake according to the FFQ was recalculated using the revised database, and the results were compared to those using the previous database. Spearman’s rank correlation coefficients (CCs) between intakes estimated by the FFQ and dietary records were computed using the revised database, and were compared to CCs computed using the previous database.

RESULTS

For most of the nutrients, mean intake increased or decreased significantly using the revised database. However, no notable change was seen for the CC between estimated intake according to dietary records and FFQ when the revised database was used for calculation. Differences in the point estimates of the CCs ranged from -0.14 to 0.15. Likewise, CCs between biomarkers and estimated intake according to FFQ were similar for the two databases.

CONCLUSION

Despite changes in intake levels for many nutrients, the validity of our FFQ using rank correlation by nutrient intake was not influenced by revision of the nutrient database in Japan.

Effects of revision of Japanese food composition tables on estimation of nutrient intakes, with reference to age-dependent differences

OBJECTIVE

To identify effects of revision of the Japanese food composition tables from the fourth version to the fifth version on nutrient intake estimation.

DESIGN

A database on 783 samples of 24-hour food duplicate portions was re-visited. Nutrients in the duplicate portions were estimated by use of the fourth and fifth versions of the Japanese food composition tables in parallel, together with supplemental use of other databases. The two sets of estimates were subjected to comparison.

SETTING

The sample collection was conducted at 31 sites all over Japan.

SUBJECTS

The sample donors were 783 women aged 20-78 years.

RESULTS

Compared with the estimates by use of the fourth version of the tables, the estimates by the fifth version were substantially higher for intakes of energy, carbohydrate, dietary fibre, vitamin A and niacin, and lower for iron intake. The increase in carbohydrate intake estimates was more evident in older women than in young women, whereas the decrease in the intake estimation of iron and the increase in that of dietary fibre were more marked in young women than in older women.

CONCLUSION

The recent revision of food composition tables in Japan induced substantial changes in the estimation of nutrient intakes, i.e. an increase in energy, carbohydrate, dietary fibre, vitamin A and niacin, and a decrease in iron. The extent of the changes varied depending on age.

Food composition table-based estimation of energy and major nutrient intake in comparison with chemical analysis: a validation study in Korea

This study was initiated to examine the accuracy of conventional food composition table-based estimation of intakes of energy, protein, lipid and carbohydrate, in comparison with chemical analysis. For this purpose, 66 women (at the ages of 29 to 54 years) in three locations in Jeju Island, Republic of Korea, volunteered to offer 24-hour food duplicate samples. A half of them were house-wives, and the remaining half were farmers or fishers. The duplicate samples were subjected 1) to the chemical analysis for daily intake of energy, protein, lipid and carbohydrate after official methods in Korea (measured values), and 2) to the estimation of intakes of the same items taking advantage of Korean Food Composition Tables (estimated values). The two sets of the results, i.e., the measured and estimated values, were compared by paired and unpaired t-test, and linear regression analysis. The estimated values correlated closely with the measured values, irrespective of energy or the three major nutrients. A close agreement was observed for energy intake (the estimated/measured ratio of > 98%), and it was also the case for protein intake (101%). Under- and over-estimation was observed, however, in regard to carbohydrate (by - 8%) and lipid intake (by + 24%), respectively. It was concluded that the Korean Food Composition Tables are sufficiently accurate when applied for estimation of total energy intake as well as protein intake. Cares should be taken, however, in applying the tables for estimation of lipid and carbohydrate intake, because there may be the risk of over- and under-estimation for the former and the latter, respectively.

Number of dishes as an indicator of nutrient intake in China

The objectives of this analysis are to investigate if counting the number of dishes consumed per day is a rapid procedure for estimating daily nutrient intake in China, and to explore if urban-rural differences exist in the daily number of dishes. A nutritional survey (including dish number counting) was conducted on 499 adult women in six urban and four rural communities in China. The number of dishes was an influential variable in estimating intake of protein, animal protein, fat, animal fat, and some vitamins (e.g., vitamin B2) and minerals (e.g., zinc), but not of energy and carbohydrate. Intake of some nutrients (e.g., protein) was sufficient when people consume more than 10 dishes per day. Thus, the number of dishes is a useful indicator of sufficient intake of animal protein and fat as well as some micro-nutrients. The application of the dish number counting method showed that there was a significant difference between urban (11.9 dishes per day) and rural populations (7.9 dishes).