Masaharu Kagawa

Olympic lightweight and open-class rowers possess distinctive physical and proportionality characteristics

Abstract Rowers competing at the 2000 Olympic Games were measured for 38 anthropometric dimensions. The aim was to identify common physical characteristics that could provide a competitive advantage. The participants included 140 male open-class rowers, 69 female open-class rowers, 50 male lightweight rowers, and 14 female lightweight rowers. Body mass, stature, and sitting height were different (P < 0.01) between the open-class and lightweight rowers, as well as a comparison group of healthy young adults (“non-rowers”, 42 males, 71 females), for both sexes. After scaling for stature, the open-class rowers remained proportionally heavier than the non-rowers, with greater proportional chest, waist, and thigh dimensions (P < 0.01). Rowers across all categories possessed a proportionally smaller hip girth than the non-rowers (P < 0.01), which suggested the equipment places some constraints on this dimension. Top-ranked male open-class rowers were significantly taller and heavier and had a greater sitting height (P < 0.01) than their lower-ranked counterparts. They were also more muscular in the upper body, as indicated by a larger relaxed arm girth and forearm girth (P < 0.01). For the male lightweight rowers, only proportional thigh length was greater in the best competitors (P < 0.01). In the female open-class rowers, skinfold thicknesses were lower in the more highly placed competitors (P < 0.01). In conclusion, the rowers in this sample demonstrated distinctive physical characteristics that distinguish them from non-rowers and other sports performers.

Validation of bioelectrical impedance analysis for total body water assessment against the deuterium dilution technique in Asian children

Background/Objectives:To develop and cross-validate bioelectrical impedance analysis (BIA) prediction equations of total body water (TBW) and fat-free mass (FFM) for Asian pre-pubertal children from China, Lebanon, Malaysia, Philippines and Thailand.Subjects/Methods:Height, weight, age, gender, resistance and reactance measured by BIA were collected from 948 Asian children (492 boys and 456 girls) aged 8–10 years from the five countries. The deuterium dilution technique was used as the criterion method for the estimation of TBW and FFM. The BIA equations were developed using stepwise multiple regression analysis and cross-validated using the Bland–Altman approach.Results:The BIA prediction equation for the estimation of TBW was as follows: TBW=0.231 × height2/resistance+0.066 × height+0.188 × weight+0.128 × age+0.500 × sex−0.316 × Thais−4.574 (R 2=88.0%, root mean square error (RMSE)=1.3 kg), and for the estimation of FFM was as follows: FFM=0.299 × height2/resistance+0.086 × height+0.245 × weight+0.260 × age+0.901 × sex−0.415 × ethnicity (Thai ethnicity =1, others = 0)−6.952 (R 2=88.3%, RMSE=1.7 kg). No significant difference between measured and predicted values for the whole cross-validation sample was found. However, the prediction equation for estimation of TBW/FFM tended to overestimate TBW/FFM at lower levels whereas underestimate at higher levels of TBW/FFM. Accuracy of the general equation for TBW and FFM was also valid at each body mass index category.Conclusions:Ethnicity influences the relationship between BIA and body composition in Asian pre-pubertal children. The newly developed BIA prediction equations are valid for use in Asian pre-pubertal children.

Day-to-day physical functioning and disability in obese 10- to 13-year-olds

What is already known about this subject? Compared with their healthy‐weight peers, children with obesity have; impaired physical health‐related quality of life reduced physical activity levels reduced capacity to perform certain weight‐bearing tasks in field‐based fitness tests

Resistivity coefficients for body composition analysis using bioimpedance spectroscopy: effects of body dominance and mixture theory algorithm

Body composition is commonly predicted from bioelectrical impedance spectroscopy using mixture theory algorithms. Mixture theory algorithms require the input of values for the resistivities of intra-and extracellular water of body tissues. Various derivations of these algorithms have been published, individually requiring resistivity values specific for each algorithm. This study determined apparent resistivity values in 85 healthy males and 66 healthy females for each of the four published mixture theory algorithms. The resistivity coefficients determined here are compared to published values and the inter-individual (biological) variation discussed with particular reference to consequential error in prediction of body fluid volumes. In addition, the relationships between the four algorithmic approaches are derived and methods for the inter-conversion of coefficients between algorithms presented.

Dietary Guidelines for the Asia Pacific Region

Nutrition is a major determinant of health throughout all stages of life and together with smoking is the most important risk factor for morbidity and mortality in the Asia Pacific Region. The workshop participants examined Dietary Guidelines and Food Guides that are in use in our region, together with additional materials from the World Health Organization, UNICEF and the World Cancer Research Foundation. The resulting set of guidelines is meant as a reminder of the main issues to be covered in a general public health education program. It may also be of value in reminding public health practitioners, educators, administrators, and policy makers of current nutrition issues. It may additionally be useful as a checklist of the issues to be considered in public health programs and regulations. The main areas of nutrition that are included in the Guidelines are eating a variety of foods, including vegetables, fruits, whole grain cereals, and nuts. Choose fish, poultry, and meats grown in a sustainable way. Appropriate growth, including avoiding obesity, and physical activity are important. Breastfeeding is the basis of infant nutrition and nutrition of mothers is an important public health measure. Negative factors in the Asian diet include salt, refined sugar, alcohol and fats. The APACPH Dietary Guidelines will need to be kept under review and modified to meet regional differences in food supply. The Guidelines will be useful as a checklist of the issues to be considered in public health programs, addressing both acute and chronic diseases.

Secular Changes in BMI and Obesity Risk in Japanese Children: Considerations from a Morphologic Perspective

The increasing prevalence of childhood obesity is a global health issue. Past studies in Japan have reported an increase in both body mass index (BMI) and risk of obesity among children and adolescents. However, changes in body size and proportion in this population over time have also influenced BMI. To date, no study of secular changes in childhood obesity has considered the impact of changes in morphological factors. The current study explored the secular changes in BMI and childhood obesity risk among Japanese children from 1950 to 2000 with consideration of changes in body size and the proportions using The Statistical Report of the School Health Survey (SHS). The age of peak velocity (PV) occurred approximately two years earlier in both genders across this period. While the increments in height, sitting height and sub-ischial leg length relative to height levelled off by 1980, weight gain continued in boys. Between 1980 and 2000, the rate of the upper body weight gain in boys and girls were 0.7-1.3 kg/decade and 0.2-1.0 kg/decade, respectively. After considering body proportions, increments in body weight were small. It could be suggested that the increments in weight and BMI across the 50-year period may be due to a combination of changes including the tempo of growth and body size due to lifestyle factors.

Ethnic Differences in the BMI-%BF Relationships between Young Japanese and Australian-Caucasian Males Living in Australia Using Dual-Energy X-ray Absorptiometry

The Body Mass Index (BMI) has been used worldwide as an indicator of fatness. However, the universal cut-off points by the World Health Organisation (WHO) classification may not be appropriate for every ethnic group when consider the relationship with their actual total body fatness (%BF). The application of population-specific classifications to assess BMI may be more relevant to public health. Ethnic differences in the BMI-%BF relationship between 45 Japanese and 42 Australian-Caucasian males were assessed using whole body dual-energy X-ray absorptiometry (DXA) scan and anthropometry using a standard protocol. Japanese males had significantly (p<0.05) greater %BF at given BMI values than Australian males. When this is taken into account the newly proposed Asia-Pacific BMI classification of BMI >23 as overweight and >25 as obese may better assess the level of obesity that is associated increased health risks for this population. To clarify the current findings, further studies that compare the relationships across other Japanese populations are recommended.

Ethical Challenges in Infant Feeding Research

Infants have a complex set of nutrient requirements to meet the demands of their high metabolic rate, growth, and immunological and cognitive development. Infant nutrition lays the foundation for health throughout life. While infant feeding research is essential, it must be conducted to the highest ethical standards. The objective of this paper is to discuss the implications of developments in infant nutrition for the ethics of infant feeding research and the implications for obtaining informed consent. A search was undertaken of the papers in the medical literature using the PubMed, Science Direct, Web of Knowledge, Proquest, and CINAHL databases. From a total of 9303 papers identified, the full text of 87 articles that contained discussion of issues in consent in infant feeding trials were obtained and read and after further screening 42 papers were included in the results and discussion. Recent developments in infant nutrition of significance to ethics assessment include the improved survival of low birth weight infants, increasing evidence of the value of breastfeeding and evidence of the lifelong importance of infant feeding and development in the first 1000 days of life in chronic disease epidemiology. Informed consent is a difficult issue, but should always include information on the value of preserving breastfeeding options. Project monitoring should be cognisant of the long term implications of growth rates and early life nutrition.

Implementation of a Nutrition Program Reduced Post-Discharge Growth Restriction in Thai Very Low Birth Weight Preterm Infants

Very low birth weight (VLBW) preterm infants are vulnerable to growth restriction after discharge due to cumulative protein and energy deficits during their hospital stay and early post-discharge period. The current study evaluated the effectiveness of the preterm infant, post-discharge nutrition (PIN) program to reduce post-discharge growth restriction in Thai VLBW preterm infants. A prospective, non-randomized interventional cohort study was undertaken to assess the growth of 22 VLBW preterm infants who received the PIN program and compared them with 22 VLBW preterm infants who received conventional nutrition services. Infant’s growth was recorded monthly until the infants reached six months’ corrected age (6-moCA). Intervention infants had significantly greater body weights (p = 0.013) and head circumferences (p = 0.009). Also, a greater proportion of the intervention group recovered their weight to the standard weight at 4-moCA (p = 0.027) and at 6-moCA (p = 0.007) and their head circumference to the standard head circumference at 6-moCA (p = 0.004) compared to their historical comparison counterparts. Enlistment in the PIN program thus resulted in significantly reduced post-discharge growth restriction in VLBW preterm infants. Further research on longer term effects of the program on infant’s growth and development is warranted.

Impaired Physical Function Associated with Childhood Obesity: How Should We Intervene?

BACKGROUND This study examined relationships between adiposity, physical functioning, and physical activity. METHODS Obese (N = 107) and healthy-weight (N = 132) children aged 10-13 years underwent assessments of percent body fat (%BF, dual energy X-ray absorptiometry); knee extensor strength (KE, isokinetic dynamometry); cardiorespiratory fitness (CRF, peak oxygen uptake by cycle ergometry); physical health-related quality of life (HRQOL); and worst pain intensity and walking capacity [six-minute walk (6MWT)]. Structural equation modelling was used to assess relationships between variables. RESULTS Moderate relationships were observed between %BF and (1) 6MWT, (2) KE strength corrected for mass, and (3) CRF relative to mass (r -0.36 to -0.69, p ≤ 0.007). Weak relationships were found between %BF and physical HRQOL (r -0.27, p = 0.008); CRF relative to mass and physical HRQOL (r -0.24, p = 0.003); physical activity and 6MWT (r 0.17, p = 0.004). Squared multiple correlations showed that 29.6% variance in physical HRQOL was explained by %BF, pain, and CRF relative to mass; while 28.0% variance in 6MWT was explained by %BF and physical activity. CONCLUSIONS It appears that children with a higher body fat percentage have poorer KE strength, CRF, and overall physical functioning. Reducing percent fat appears to be the best target to improve functioning. However, a combined approach to intervention, targeting reductions in body fat percentage, reductions in pain, and improvements in physical activity and CRF may assist physical functioning.