Kazuhiro Uenishi

Misreporting of dietary energy, protein, potassium and sodium in relation to body mass index in young Japanese women

Objective:Although under-reporting of dietary intake is more common in persons with a high body mass index (BMI), it is not well known whether or not misreporting is selective for different foods (and hence energy and nutrients), particularly in non-Western populations. We examined misreporting of dietary intake against biomarkers and its relation with BMI in young Japanese women.Design:Cross-sectional study.Subjects:A total of 353 female Japanese dietetic students aged 18–22 years (mean BMI: 21.4 kg/m2, mean fat intake: 29.8% of energy).Methods:Misreporting of dietary energy, protein, potassium and sodium (assessed by a self-administered diet history questionnaire) was examined against respective biomarkers (estimated energy expenditure and 24-h urinary excretion). Reporting accuracy was calculated as the ratio of reported intake to that estimated from corresponding biomarkers (complete accuracy: 1.00).Results:Mean reporting accuracy of absolute intake (amount per day) varied considerably (0.86–1.14). Reporting accuracy of absolute intake decreased with increasing BMI (P for trend <0.001). However, no association was observed between reporting accuracy of energy-adjusted values and BMI (P for trend >0.15), indicating that BMI-dependent misreporting was canceled by energy adjustment. This was owing to positive correlation between the reporting accuracy of energy intake and that of absolute intake of the three nutrients (Pearson correlation coefficient: 0.49–0.67, P<0.0001).Conclusions:Although differential misreporting of absolute intake was associated with BMI, differential misreporting of energy-adjusted value was not. These findings support the use of energy-adjusted values in the investigation of diet–disease relationships among lean populations with a low-fat intake.

Association between dietary acid-base load and cardiometabolic risk factors in young Japanese women.

Mild metabolic acidosis, which can be caused by diet, may adversely affect cardiometabolic risk factors, possibly by increasing cortisol production. Methodologies for estimating diet-induced acid-base load using dietary-intake information have been established. To our knowledge, however, the possible association between dietary acid-base load and cardiometabolic risk factors has not been investigated. We cross-sectionally examined associations between dietary acid-base load and cardiometabolic risk factors in a free-living population. The subjects were 1136 female Japanese dietetic students aged 18-22 years. Dietary acid-base load was characterized as the potential renal acid load (PRAL), which was determined using an algorithm including dietary protein, P, K, Ca and Mg, as well as the ratio of dietary protein to K (Pro:K). Estimates of each nutrient were obtained from a validated comprehensive self-administered diet history questionnaire. Body height and weight, waist circumference and blood pressure were measured. Fasting blood samples were collected. After adjustment for potential confounding factors, higher PRAL and Pro:K (more acidic dietary acid-base loads) were associated with higher systolic and diastolic blood pressure (P for trend = 0.028 and 0.035 for PRAL and 0.012 and 0.009 for Pro:K, respectively). PRAL was also independently positively associated with total and LDL-cholesterol (n 1121; P for trend = 0.042 and 0.021, respectively). Additionally, Pro:K showed an independent positive association with BMI and waist circumference (P for trend = 0.024 and 0.012, respectively). In conclusion, more acidic dietary acid-base load was independently associated with adverse profile of several cardiometabolic risk factors in free-living young Japanese women.

Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women

BackgroundVitamin K2 contributes to bone and cardiovascular health. Therefore, two vitamin K2 homologues, menaquinone-4 (MK-4) and menaquinone-7 (MK-7), have been used as nutrients by the food industry and as nutritional supplements to support bone and cardiovascular health. However, little is known about the bioavailability of nutritional MK-4. To investigate MK-4 and MK-7 bioavailability, nutritional doses were administered to healthy Japanese women.FindingsSingle dose administration of MK-4 (420 μg; 945 nmol) or MK-7 (420 μg; 647 nmol) was given in the morning together with standardized breakfast. MK-7 was well absorbed and reached maximal serum level at 6 h after intake and was detected up to 48 h after intake. MK-4 was not detectable in the serum of all subjects at any time point. Consecutive administration of MK-4 (60 μg; 135 nmol) or MK-7 (60 μg; 92 nmol) for 7 days demonstrated that MK-4 supplementation did not increase serum MK-4 levels. However, consecutive administration of MK-7 increased serum MK-7 levels significantly in all subjects.ConclusionsWe conclude that MK-4 present in food does not contribute to the vitamin K status as measured by serum vitamin K levels. MK-7, however significantly increases serum MK-7 levels and therefore may be of particular importance for extrahepatic tissues.

Stature estimation formulae from radiographically determined limb bone length in a modern Japanese population

The objective of this study was to derive regression formulae for stature estimation from long limb bones in a Japanese population. Moreover, commonly employed estimation equations, such as that of Fujii, were re-evaluated through application of current data. To construct equations, measurements were conducted on 434 living subjects (342 females and 92 males; 18-59years old). The whole or maximum length of the femur, tibia, and humerus was determined radiographically using dual-energy X-ray absorptiometry, which permitted measurement of long bones with no magnification. Regression formulae were constructed for females and males relative to the real body height measured in the erect position. Lower limbs of the femur and tibia were more accurate predictors (R=0.813-0.903) than the humerus was (R=0.670-0.708). Multiple regression models were produced for all three bones and the two leg bones, revealing no significant difference between R values. Comparison of these equations with those of earlier studies of Andou and Fujii verified differences in estimated stature, indicating that stature estimation formulae should be constructed based on current data obtained from precise physical measurements. These equations will benefit forensic anthropology and nutrition science for stature estimation of contemporary Japanese individuals.

Total n-3 polyunsaturated fatty acid intake is inversely associated with serum C-reactive protein in young Japanese women.

Little is known about the relation of dietary factors to circulating C-reactive protein (CRP) concentrations in young adults and non-Western populations. We cross-sectionally examined associations between dietary intake and serum CRP concentrations in young Japanese women. The subjects were 443 female Japanese dietetic students aged 18 to 22 years. Dietary intake was assessed with a validated, self-administered, comprehensive, diet history questionnaire. Serum CRP concentrations were measured by highly sensitive nephelometry. The prevalence of elevated CRP (> or = 1 mg/L) was 5.6%. After adjustment for possible confounding factors including body mass index, a significant inverse association was seen between total n-3 polyunsaturated fatty acid intake and elevated CRP. The multivariate adjusted odds ratios of elevated CRP for women with intake below and above the median (1.1% of energy) were 1.00 and 0.33 (95% confidence interval, 0.13-0.82; P = .02), respectively. Intake of eicosapentaenoic acid + docosahexaenoic acid and alpha-linolenic acid was not associated with elevated CRP concentrations (P = .62 and P = .27, respectively). Vitamin C intake was independently inversely associated with elevated CRP, although the association was nonsignificant (P = .10). No clear associations were observed for other dietary factors examined including total fat, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, total dietary fiber, soluble dietary fiber, insoluble dietary fiber, and magnesium; fruits, vegetables, and fish and shellfish; and dietary glycemic load (P = .27 to P = .99). In conclusion, total n-3 polyunsaturated fatty acid intake showed an independent inverse association with elevated serum CRP concentration in a group of young Japanese women.

Calcium requirement estimated by balance study in elderly Japanese people.

Abstract: The recommended dietary allowance (RDA) for calcium (Ca) of Japanese adults is proposed to be 600 mg/day, which is lower than those of other countries. In this report we estimated the Ca requirement and the RDA for Ca in elderly Japanese utilizing a Ca balance method. Subjects were 10 men aged 65–72 years and 10 women aged 62–77 years. Following a 14 day adaptation period, each participant was subjected to a low Ca diet (Ca 250 mg as a meal) for 6 days. After an interval of 2 weeks or more, another 14 day adaptation period was set and then a high Ca diet (Ca 250 mg as a meal and 600 mg as CaCO3) was served to the subjects for 6 days. Ca balance was calculated at each dose of Ca intake. Ca requirement was estimated by the intersection of the average Ca intake–retention diagram. Daily Ca requirement was 702 mg in the men and 788 mg in the women. The Ca requirement values were multiplied by 1.2 to obtain the RDA for Ca. As a result, RDA for Ca was 842 mg/day for men and 946 mg/day for women. When these values were normalized with the body weight, the RDA for Ca of Japanese and Caucasian women was similar (18.1 and 18.5 mg/kg body weight per day, respectively). Our results suggest the difference in Ca balance between the genders and among populations may be ascribed at least partly to differences in body size. In addition, body weight should be considered when comparing the RDAs among different populations.

Monetary cost of self-reported diet in relation to biomarker-based estimates of nutrient intake in young Japanese women.

OBJECTIVE All previous studies on monetary diet cost have examined the relationship of monetary cost of self-reported diet to self-reported, rather than biomarker-based, estimates of dietary intake. The present cross-sectional study examined the association between monetary costs of self-reported diet and biomarker-based estimates of nutrient intake. DESIGN Monetary diet cost (Japanese yen/1000 kJ) was calculated based on dietary intake information from a self-administered, comprehensive diet history questionnaire using retail food prices. Biomarker-based estimates of nutrient intake (percentage of energy for protein and mg/1000 kJ for K and Na) were estimated based on 24 h urinary excretion and estimated energy expenditure. SETTING A total of fifteen universities and colleges in Japan. SUBJECTS A total of 1046 female Japanese dietetic students aged 18-22 years. RESULTS Total monetary diet cost showed a significant positive association with biomarker-based estimates of protein, K and Na. Vegetables and fish were not only the main contributors to total monetary diet cost (16.4 % and 15.5 %, respectively) but also were relatively strongly correlated with total monetary diet cost (Pearsons correlation coefficient: 0.70 and 0.68, respectively). Monetary cost of vegetables was significantly positively associated with all three nutrients, while that of fish showed a significant and positive association only with protein. CONCLUSIONS Total monetary cost of self-reported diet was positively associated with biomarker-based estimates of protein, K and Na intake in young Japanese women, and appeared mainly to be explained by the monetary costs of vegetables and fish.

Neighborhood food store availability in relation to food intake in young Japanese women

OBJECTIVE Information on the association between the local food environment and the diet of individuals is limited, particularly in settings with high population density and, hence, high food-store density, such as Japan. This cross-sectional study examined the association between neighborhood food-store availability and individual food intake in a group of young Japanese women. METHODS Participants were 990 female Japanese dietetic students 18-22 y of age. Neighborhood food-store availability was defined as the number of food stores within a 1-km mesh-block of residence, derived from the census of commerce. Dietary intake was estimated using a validated, comprehensive self-administered diet-history questionnaire. RESULTS After adjustment for potential confounding factors, including household socioeconomic status, geographic variables, and the frequency of eating out, neighborhood store availability for confectioneries and bread (based on confectionery stores/bakeries, supermarkets, and grocery and convenience stores) was significantly positively associated with the intake of confectioneries and bread. No significant independent association was seen between neighborhood store availability for the other foods examined, including meat (meat stores, supermarkets, and grocery stores), fish (fish stores, supermarkets, and grocery stores), fruit and vegetables (fruit/vegetable stores, supermarkets, and grocery stores), and rice (rice stores, supermarkets, and grocery and convenience stores) with intake of each food. CONCLUSION In a group of young Japanese women, increasing neighborhood store availability for confectioneries and bread was independently associated with higher intake of confectioneries and bread. In contrast, no association between availability and intake was seen for meat, fish, fruit and vegetables, or rice.

Lower estimates of δ-5 desaturase and elongase activity are related to adverse profiles for several metabolic risk factors in young Japanese women

Little is known about the relation between the activities of certain enzymes involved in endogenous fatty acid synthesis and metabolic risk factors, particularly in young adults and non-Western populations. In this cross-sectional study, we examined the associations between estimated desaturase and elongase activities and metabolic risk factors in young Japanese women. The subjects were 640 female Japanese dietetic students aged 18 to 22 years. Body height and weight, from which body mass index (BMI) was derived, waist circumference, and blood pressure were measured. Fasting blood samples were collected for biochemical and fatty acid measurements. Desaturase and elongase enzyme activities were estimated as the ratio of product to precursor of individual fatty acids in serum lipids. delta-9 desaturase activity was positively associated with BMI, diastolic blood pressure, total and low-density lipoprotein cholesterol, and triacylglycerol and was negatively associated with high-density lipoprotein cholesterol (P <or= .019). delta-6 desaturase activity showed positive associations with BMI, systolic blood pressure, triacylglycerol, and the homeostasis model assessment of insulin resistance (P <or= .045). delta-5 desaturase activity showed independent negative associations with BMI, systolic blood pressure, triacylglycerol, insulin, and the homeostasis model assessment of insulin resistance (P <or= .007). Elongase activity was associated negatively with BMI, systolic and diastolic blood pressures, and triacylglycerol and was positively associated with high-density lipoprotein cholesterol (P <or= .026). In conclusion, increased estimates of delta-9 and delta-6 desaturase activity and decreased estimates of delta-5 desaturase and elongase activity were associated with adverse profiles for several metabolic risk factors in young Japanese women.

The degree of misreporting of the energy-adjusted intake of protein, potassium, and sodium does not differ among under-, acceptable, and over-reporters of energy intake

It is unclear whether misreporting of nutrient intakes differs according to energy reporting status. We examined misreporting of dietary protein, potassium, and sodium in under-, acceptable, and over-reporters of energy intake. Our hypothesis was that degree of misreporting of these three nutrients differs among under-, acceptable, and over-reporters. Participants were 1043 Japanese women aged 18 to 22 years. Self-reported dietary intake was obtained using a diet history questionnaire. Under-, acceptable, and over-reporters of energy intake were identified based on the ratio of self-reported energy intake to estimated energy requirement (<0.70 [17.2%], 0.70-1.30 [78.1%], and >1.30 [4.7%], respectively). Misreporting of dietary protein, potassium, and sodium was assessed against the corresponding biomarker-based estimate derived from 24-hour urinary excretion. On average, the degree of misreporting of intake of energy and the three nutrients varied considerably. Absolute intake (amount per day) of the three nutrients was under-reported in under-reporters of energy intake and over-reported in over-reporters compared with acceptable reporters. However, mainly because of high correlations between the ratio of self-reported energy intake to estimated energy requirement and the ratio of self-reported to biomarker-based estimates of absolute intake of three nutrients (Pearson correlation coefficient: 0.64 for protein, 0.51 for potassium, and 0.37 for sodium), the degree of misreporting of the energy-adjusted intake of these nutrients based on the density method did not differ across categories of energy reporting status. In conclusion, these findings may lend support to the usefulness of adjustment for energy misreporting and the futility of merely excluding energy misreporters from analysis.