SummaryThe aim of the present study is to investigate the validity of a new method to estimate the food intake of individual subjects by a household-based dietary survey . The new method is based on the combination of household-based food weighing and approxi mating the proportions by which family members shared each dish or food in the house hold, which has been one of the components of the National Nutrition Survey, Japan , since 1995. We analyzed two sets of data from 64 volunteers (female students taking a dietitian course and their mothers) in 32 households by the approximated proportion method (method A) and the individual-based food weighing method (B) as a reference measurement. Energy and macronutrient intake by individual subjects estimated by method A was highly correlated to the corresponding values by method B (Pearson's correlation coefficients; r=0.90-0,92).Average energy intake was likely to be underestimated by method A com pared with method B, being lower by 94kcal (6.2% of the reference value in method B), at least in the young and middle-aged female adults that were the subjects of this study . When intake of boiled rice was separately analyzed , underestimation of energy intake by method A was 44kcal, which contributed to approximately 50% of the total magnitude of the under estimation. The procedure manual for the National Nutrition Survey requests the partici pants to individually weigh the amount of boiled rice taken by family members in the house hold. However, this procedure is not observed in many actual settings . Therefore, following this procedure would be an effective measure to improve the accuracy of the dietary data . Key Words dietary survey, food weighing method , individual-based survey, validation, biasThe dietary survey is a core component of nation wide nutrition monitoring (1), including the National Nutrition Survey, Japan (NNS-J), The NNS-J was initi ated in 1946 with the main purpose of obtaining basic information for emergency food supplies from other countries (2), Thus, household-based food consumption data had been conventionally collected from the stand point of food security. The aim of the survey, however, has shifted from food supply issues to chronic disease prevention, and individual-based dietary data have be come essential to clarify diet-disease relationships .A new method (hereinafter called the approximated proportion method) to estimate the food intake of individ ual subjects in a household has been used in the NNS-J since 1995. This method is based on a combination of household-based food weighing and an approximation of proportions by which family members shared each dish or kind of food in the household (3 , 4) (Fig. 1). This hybrid method was adopted by the NNS-J because it was * To whom correspond ence should be addressed. E-mail: nobuoyos@nih.go.jp expected to allow comparisons with dietary data that had been conventionally collected for more than 50 years by the household-based food weighing method.The aim of the study is to investigate the valid...

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The age-adjusted death rate from ischemic heart disease in Japan is the lowest among developed countries and the rates have decreased since 1970. The incidences of myocardial infarction in selected populations ranged between 0.12 and 2.56 per 1,000 for middle-aged males, and between 0.00 and 1.52 per 1,000 for females. The incidences of sudden death within 24 hours were from 0.00 to 1.58 per 1,000 for males and from 0.00 to 0.76 per/1,000 for females. The incidences in Japanese populations appeared to be far below those in Western populations. In the Cox proportional hazard regression model, hypertension and smoking were selected as independent risk factors for myocardial infarction in an agricultural district. It was noteworthy that the level of serum cholesterol was not associated with development of myocardial infarction in rural areas. No positive relation between dietary fat and serum cholesterol was observed in school children, suggesting that growth, sexual maturation and others might be confounding variables between them. The levels of serum cholesterol for females were more affected by menopause than those of blood pressures and body mass index. Although some polymorphisms in selected candidate genes appeared to be associated with some serum lipids and apolipoproteins, the effect of individual RFLP on the inter-individual variations in serum traits was relatively subtle in comparison with that of lifestyle factors.

SummaryThe reliability and validity of two newly developed den sitometric methods for determining the human body volume and per cent body fat (%FAT), the sulfur hexafluoride dilution method (SHF) and air displacement plethysmography (ADP), were evaluated in com parison with the underwater weighing method (UWW). Seven healthy male volunteers (age 31 to 44, mean height 166.0cm, weight 61.4kg) participated in this study. The same-day test-retest coefficients of variation (CVs) for body volume and %FAT measurements were not significantly different among the three methods. SHF and UWW showed a strong correlation in terms of body volume and %FAT, with the correlation coefficients (r) being 0.9997 and 0.986, respectively. The correlation between ADP and UWW was slightly weaker (r=0.9997 for body volume and 0.907 for %FAT). However, body volumes measured by SHF and ADP were significantly different from that by UWW when compared by mean values. Such differences were also found for %FAT measurements. The regression lines of body volume measured by SHF and ADP on that by UWW were almost equivalent to the line of identity. However, those of %FAT measured by SHF and ADP on that by UWW were sig nificantly different from the line of identity. Because the reliability of SHF and ADP appeared to be high, further validation and improvement are required and worth doing.