Hiroshi Kashiwazaki

Correlations of pedometer readings with energy expenditure in workers during free-living daily activities

SummaryIn a total of 23 subjects consisting of 10 clerical and 13 assembly workers in a factory, the pedometer readings during a day of free-living activity were analyzed for the relation with energy expenditure as determined by the simultaneously recorded 24-hour heart rate. The 24-hour energy expenditures in the clerical and assembly workers were 9515 kJ (2274 kcal) and 9698 kJ (2318 kcal) respectively. The whole day readings of the pedometer for all the subjects moderately correlated (r=0.438,p<0.05) with the net energy cost (NEC) as determined by subtracting the sleeping metabolic cost from the energy expenditure (clerical workers:r=0.781,p<0.01; assembly workers:r=0.188,p>0.05). The correlation analysis of the pedometer readings with the NEC in three activity phases in a day (work, commuting and staying at home), showed that the extent of the relationship differed by job types and activity phases. The best correlation was obtained during commuting in both of the job types (clerical workers:r=0.843,p<0.01; assembly workers:r=0.743,p<0.01). During work, a quite strong correlation (r=0.889,p<0.01) was obtained with the clerical workers but not with the assembly workers. No significant correlations were found in the data while the subjects were at home. The capacity of the pedometer to detect the impacts of body movements, and the characteristics of activity, are responsible for the differences in correlation. The limitations of the pedometer suggested in the present study must be taken into account if the device is to be used for measuring physical activity. A particular advantage of the device appears in its use for a sedentary population without regular srenuous exercise or static contractions.

Year-round high physical activity levels in agropastoralists of Bolivian Andes: results from repeated measurements of DLW method in peak and slack seasons of agricultural activities.

By the repeated use of the doubly labeled water method (DLW), this study aimed to investigate (1) the extent of changes in energy expenditure and physical activity level (PAL) in response to increased agricultural work demands, and (2) whether the seasonal work demands induce the changes in the fairly equitable division of work and similarity of energy needs between men and women observed in our previous study (Phase 1 study; Kashiwazaki et al., 1995 : Am J Clin Nutr 62: 901–910). In a rural small agropastoral community of the Bolivian Andes, we made the follow‐up study (Phase 2, 14 adults; a time of high agricultural activity) of the Phase 1 study (12 adults; a time of low agricultural activity). In the Phase 2 study, both men and women showed very high PAL (mean±SD), but there was no significant difference by sex (men; 2.18 ± 0.23 (age; 64 ± 11 years, n = 7), women; 2.26 ± 0.25 (63 ± 10 years, n = 7)). The increase of PAL by 11% (P = 0.023) in the Phase 2 was equally occurred in both men and women. The factorial approach underestimated PAL significantly by ≈15% (P < 0.05). High PAL throughout the year ranging on average 2.0 and 2.2 was attributable to everyday tasks for subsistence and domestic works undertaking over 9–11 h (men spent 2.7 h on agricultural work and 4.7 h on animal herding, whereas women spent 7.3 h almost exclusively on animal herding). The seasonal increase in PAL was statistically significant, but it was smaller than those anticipated from published reports. A flexible division of labor played an important role in the equitable energetic increase in both men and women. Am. J. Hum. Biol., 2009.

Dietary habit and selenium concentrations in erythrocyte and serum in a group of middle-aged and elderly japanese

Abstract We examined whether selenium (Se) levels in blood were related to dietary habits, age, sex, smoking, consumption of alcoholic beverages or obesity in a group of men and women above 40 years of age. Mean Se concentration in erythrocytes (ESe) was 244±50 (mean±SD) for males, and 235±36 ng/g for females; mean Se concentration in serum (SSe) was 111±19 for males, and 107±16 ng/ml for females. Multiple regression analysis revealed that the following variables were significant in determining ESe and SSe levels: fish consumption, age, and consumption of alcoholic beverages for ESe; and age, pattern of staple food consumption, and hemoglobin concentration in the blood for SSe.

Daily energy expenditure of middle-aged Japanese housewives measured by 24-hour heart rate and diary

Abstract Measurements of daily energy expenditure were made in 20 middle-aged Japanese housewives by 24-hour heart rate monitoring. The values were compared with the estimates derived from the diaries being simultaneously recorded by the subjects on the nature and duration of activities during the 24-hours. The mean of the energy expenditure derived from the 24-hour heart rate was 1476 kcal, while the mean of the estimates from the diaries was 2007 kcal. The assessed error in the heart rate method was about 10% over-estimation. As the energy expenditure derived from the diary method was 36% greater than that of the heart rate method, the error involved in the diary method was much greater than that in the heart rate method. The difference in the estimation between the two methods resulted from two causes. The first is in the resting metabolic rate which accounts for a 15% greater estimate; 0.84 kcal/min (31.0 kcal/kg fat-free mass/24 hour) determined by oxygen consumption, and 0.96 kcal/min (35.6 kcal/kg fat-free mass/24 hour) calculated from the Japanese standard basal metabolic rate. The second is a suggested limitation of the diary method that the recorded activities may not appropriately reflect dominant activities, which accounts for the rest of 21% greater estimate. If the daily energy expenditure is estimated on the basis of the diary method without knowing the extent of error involved, an erroneous conclusion would be drawn.

Geographical variation in urinary mercury concentrations among populations living in highland and lowland Bolivia

Mercury (Hg) concentrations were determined in spot urine samples of populations living in the highland and lowland areas of Bolivia. The mean levels of the Hg (U-Hg) were 0.43 and 0.34 micrograms Hg/g creatinine in lowlanders and in highlanders, respectively, which did not suggest existence of high-level exposure to Hg in these populations. In both highlanders and lowlanders, there was a marked difference in levels of U-Hg among different populations. Several lines of evidence suggested that local dietary patterns resulted in the observed difference in U-Hg among different populations. Several lines of evidence suggested that local dietary patterns resulted in the observed difference in U-Hg levels, although the responsible food items could not be specified. In most of the populations examined, females showed higher U-Hg levels than males. Other factors possibly related to the observed geographical differences are discussed.

A spontaneous increase of salt intake and changes of colonic temperature in mice exposed to cold

The effect of repeated short-term exposure to cold on spontaneous salt (NaCl) intake and colonic temperature was investigated in two experiments on mice. In Experiment 1, half of a group of test animals were exposed to cold (7-9 degrees C; 6h/day; 4 days), and half of both the exposed and non-exposed animals were allowed to choose between drinking water with (0.9%) and without (0%) NaCl. Food and fluids were provided all day long during the experiment. Mice provided with NaCl solution showed increased salt intake with cold exposure. Colonic temperature of mice was measured twice a day at the beginning and the end of cold exposure. Different changes in colonic temperature among the groups were observed at the end of cold exposure. In mice exposed to cold and provided with NaCl solution, colonic temperatures stayed unchanged, whereas in those without NaCl solution colonic temperatures decreased significantly after cold exposure. In Experiment 2, all the mice were exposed to cold as in Experiment 1. Four patterns of feeding of food and fluids were applied to groups of eight mice each: removal of food and fluids during cold; removal during 9 h before cold and during cold; removal during cold and during 9 h after cold, and feeding all day long. Half the mice in each feeding pattern were allowed to choose NaCl fluids (0% & 0.9%). Colonic temperature was measured as in Experiment 1. In all the feeding patterns, colonic temperature was significantly lower in the mice without NaCl solution than those with NaCl solution. Among four feeding patterns in mice with NaCl solution, colonic temperature was significantly higher in the case of feeding all day long than in the other three patterns.

Agricultural Practices and Household Organization in a Japanese Pioneer Community of Lowland Bolivia

This article describes the colonization process of the Japanese pioneer farmers in the Bolivian subtropical lowlands. Quantitative data for each of the farm households that can be matched for comparison between the initial phase of colonization and a later phase provide the basis for an examination of a reciprocal relationship between household organization and successively introduced agricultural practices. Two hypotheses are tested: (a) pioneer agriculture stimulates the formation of large family households to cope with an assumed labor shortage; and (b) existing variation in household organization produces variation in agricultural practices. The analysis reveals that the size of swidden farming in the initial phase and the size of permanent field cultivation in the latter phase both relate positively to the size of the male labor force. Despite the significant advantage of a large family household for providing free labor during rapid agricultural growth, a diachronic analysis does not support the hypothesis that the pioneer condition stimulates adaptive social change toward the formation of large families. Rather, the data indicate that changes in household composition have major effects on the size of cropland and the transformation from swidden farming to mechanized cultivation. Underlying mechanisms of agricultural change are further explored, and the implications for a colonization project are discussed.

Changing food consumption of Japanese immigrants in the lowland of Bolivia

Dietary records (a three‐day period in July and August, 1975) of 34 households of Japanese immigrants in the lowland of Bolivia were analyzed for the amounts and types of food consumed. The objective of the study was to determine the food habits of immigrants during the various stages of their resettlement and socio‐economic development. The results were as follows: The number of foodstuffs exceeded 100, among which rice was staple through all the households. Food‐stuffs or foodstuff‐groups of high communality in consumption next to rice were vegetables, oils wheat, eggs and sugar. Use of wild river fish and cultivation of vegetables, novel in Bolivia but familiar in Japan, were widely recognized. Differences due to the diversified subsistence activities were mainly observed in consumption of animal food such as beef, chicken and fish. Non‐agriculturists more frequently consumed wheat, non‐alcoholic beverages, and jam and honey, and less frequently rice, vegetables, eggs and vinegar. Except for soybean pr...