Comparison of seasonal variation in the fasting respiratory quotient of young Japanese, Polish and Thai women in relation to seasonal change in their percent body fat

Background

From the viewpoint of human physiological adaptability, we previously investigated seasonal variation in the amount of unabsorbed dietary carbohydrates from the intestine after breakfast in Japanese, Polish and Thai participants. In this investigation we found that there were significant seasonal variations in the amount of unabsorbed dietary carbohydrates in Japanese and Polish participants, while we could not find significant seasonal variation in Thai participants. These facts prompted us to examine seasonal variations in the respiratory quotient after an overnight fast (an indicator of the ratio of carbohydrate and fat oxidized after the last meal) with female university students living in Osaka (Japan), Poznan (Poland) and Chiang Mai (Thailand).

Methods

We enrolled 30, 33 and 32 paid participants in Japan, Poland and Thailand, respectively, and measurements were taken over the course of one full year. Fasting respiratory quotient was measured with the participants in their postabsorptive state (after 12 hours or more fasting before respiratory quotient measurement). Respiratory quotient measurements were carried out by means of indirect calorimetry using the mixing chamber method. The percent body fat was measured using an electric bioelectrical impedance analysis scale. Food intake of the participants in Osaka and Poznan were carried out by the Food Frequency Questionnaire method.

Results

There were different seasonal variations in the fasting respiratory quotient values in the three different populations; with a significant seasonal variation in the fasting respiratory quotient values in Japanese participants, while those in Polish and Thai participants were non-significant. We found that there were significant seasonal changes in the percent body fat in the three populations but we could not find any significant correlation between the fasting respiratory quotient values and the percent body fat.

Conclusions

There were different seasonal variations in the fasting respiratory quotient values in the three different populations. There were significant seasonal changes in the percent body fat in the three populations but no significant correlation between the fasting respiratory quotient values and the percent body fat.     

Relationship between the percentage of body fat and surrogate indices of fatness in male and female Polish active and sedentary students

Background

Limited data have indicated that body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR) and waist to height ratio (WHtR) of athletes and young adults provide misleading results concerning body fat content. This study was aimed at the evaluation of the relationship between different surrogate indices of fatness (BMI, WC, WHR, WHtR and body adiposity index (BAI)) with the percentage of body fat in Polish students with respect to their sex and physical activity.

Methods

A total of 272 students volunteered to participate in the study. Of these students, 177 physical education students (90 males and 87 females) were accepted as active (physical activity of 7 to 9 hours/week); and 95 students of other specializations (49 males and 46 females) were accepted as sedentary (physical activity of 1.5 hours/week). Weight, height, waist and hip circumferences were measured, and BMI, WHR, WHtR and BAI were calculated. Body fat percentage was assessed using four skinfold measurements.

Results

Classification of fatness according to the BMI and the percentage of body fat have indicated that BMI overestimates fatness in lean subjects (active men and women, sedentary men), but underestimates body fat in obese subjects (sedentary women). In all groups, BMI, WHR, WHtR and BAI were significantly correlated with the percentage of body fat (with the exception of WHR and hip circumference in active and sedentary women, respectively). However, coefficients of determination not exceeding 50% and Lin’s concordance correlation coefficients lower than 0.9 indicated no relationship between measured and calculated body fat.

Conclusion

The findings in the present study support the concept that irrespective of physical activity and sex none of the calculated indices of fatness are useful in the determination of body fat in young adults. Thus, it seems that easily calculated indices may contribute to distorted body image and unhealthy dietary habits observed in many young adults in Western countries, but also in female athletes.     

Relationship of Body Composition to Body‐Fatness Estimation in Japanese University Students

Objective: To examine the relationship between self‐estimated whole body size and fatness and whole body and regional composition, and the relationship between self‐estimated whole body fatness and self‐estimated regional fatness in Japanese university students. Research Methods and Procedures: This was a cross‐sectional study using Japanese university students (110 men and 79 women). The percentage of body fat, fat mass (FM), and fat‐free mass (FFM) were measured by underwater weighing and used as body composition variables. Subcutaneous fat thicknesses were determined at seven sites by ultrasonography to estimate regional body composition, and six circumferences and four breadths to estimate regional size. Relative body size and fatness were self‐estimated using a questionnaire. Results: Only women tended to estimate themselves as being fatter than they actually were. Self‐estimated body fatness moderately correlated with the percentage of body fat (men, r = 0.41; women, r = 0.40) FM (men, r = 0.50; women, r = 0.51), and body mass index (r = 0.56 for men and 0.56 for women). After adjusting for the percentages of body fat and FM, self‐estimated fatness correlated with body mass index (r = 0.31 for men and r = 0.37 for women). Among self‐estimated regional fatness, self‐estimated abdominal fatness had the strongest correlation with self‐estimated whole body fatness in both genders. Discussion: The low correlation between estimated and actual body fatness in both genders indicates that Japanese university students, especially women, inaccurately estimate their percentage of body fat. In fact, both men and women primarily estimate their whole body fatness by body weight relative to height.     

广西少数民族成年女性体成分的差异及年龄变化规律

本文分析了在广西调研的860例(毛南族200例、仫佬族200例、苗族244例、瑶族216例)少数民族女性的体成分数据,结果发现:1)不同民族的体成分比较,脂肪量苗族最高,仫佬族最低,肌肉量毛南族最高,苗族最低,组间差异多数具有统计学意义(P<0.05)。2)广西毛南族、仫佬族、苗族和瑶族成年女性的身体质量指数(I_(bm))、腰臀比(R_(wh))及体脂肪率(P_(bf))差异明显,根据I_(bm)、R_(wh)或P_(bf)评价的肥胖人数比率最高的均为苗族,且与其它民族的差异具有统计学意义(P<0.05)。3)广西毛南族、仫佬族、苗族和瑶族女性的脂肪量均随年龄的增长先升高,一般至50-54岁达高峰再稍下降,而去脂体重随年龄的增长逐渐波动降低;四民族女性的肌肉量总体随年龄的增长呈波动下降的趋势,毛南族最为明显;四民族各年龄段之间的体成分比较,组间差异绝大多数具有统计学意义(P<0.05)。综上所述,体成分存在民族差异,苗族女性的体成分状况最不健康,表现为脂肪含量过高而肌肉量和骨量偏低;随年龄的增长,本研究四个少数民族的体成分均可能呈现少肌性肥胖和骨质疏松的危险倾向。     

黎族的体成分与体质特征

1982年和1988年已经有学者报道了黎族体质人类学研究资料,近年来又报道了黎族的分子人类学研究成果。目前未见关于黎族身体组成成分的研究,也没有当前黎族的体质人类学数据。2014年11月,在海南省五指山市5个黎族村寨进行607例(男为308例,女为299例)黎族成人的人体测量。研究发现,黎族人偏瘦,肌肉较发达。随年龄增长,黎族男性体脂率的增加,主要是躯干脂肪率增大造成的,与四肢脂肪率关系不大。男性由于骨量、躯干和四肢肌肉量的下降造成瘦体质量的逐渐减小。随年龄增长,黎族女性的体脂率呈线性增大,总肌肉量呈线性减小。体脂率的逐渐增大是由于躯干和四肢的脂肪率逐渐增加造成的,总肌肉量的逐渐减小是左下肢肌肉量、躯干肌肉量逐渐下降造成的。黎族男女均为圆头型、高头型、中头型、阔面型、中鼻型、中躯干型、中胸型、宽肩型、中骨盆型、中腿型。与30年前黎族头面部资料相比,本文测量的黎族头宽、面宽值较大,头更圆些、更阔些,面更阔些,红唇较薄,形态面高值较小,男性鼻宽值较小。     

Strong influence of dietary intake and physical activity on body fatness in elderly Japanese men: age-associated loss of polygenic resistance against obesity

Genome-wide association studies identified single nucleotide polymorphisms (SNPs) associated with body mass index (BMI) in middle-aged populations; however, it is unclear whether these SNPs are associated with body fatness in elderly people. We examined the association between genetic risk score (GRS) from BMI-associated SNPs and body fatness in elderly Japanese men. We also examined the contribution of GRS, dietary macronutrient intake, and physical activity to body fatness by different age groups. GRS was calculated from 10 BMI-associated SNPs in 84 middle-aged (30–64 years) and 97 elderly (65–79 years) Japanese men; subjects were divided into low, middle, and high GRS groups. Dietary macronutrient intake was assessed using a questionnaire, and physical activity was evaluated using both a questionnaire and an accelerometer. The middle-aged individuals with a high GRS had greater BMI; waist circumference; and total abdominal fat, visceral fat, and subcutaneous fat areas than the middle-aged individuals with low GRS, whereas the indicators were not different between the GRS groups in elderly individuals. Multiple linear regression analysis showed that GRS was the strongest predictor of BMI, total abdominal fat, and visceral fat in the middle-aged group, whereas fat, alcohol, and protein intakes or vigorous-intensity physical activity were more strongly associated with these indicators than was GRS in the elderly group. These results suggest that GRS from BMI-associated SNPs is not predictive of body fatness in elderly Japanese men. The stronger contribution of dietary macronutrient intake and physical activity to body fatness may attenuate the genetic predisposition in elderly men.     

Muscle strength and body composition as determinants of blood pressure in young men

The correlations of blood pressure to various indices of muscularity and fatness were studied in 183 young healthy men (mean age 19.7, SD 2.1 years). Systolic pressure showed significant positive correlations with body fat percentage, isometric strength of trunk extensors, body mass index, lean body mass, strength of leg extensors, heart rate, and the sum of four skinfolds. Diastolic pressure had significant positive correlations with body mass index, lean body mass, body fat percentage, sum of skinfolds, strength of leg extensors, strength of trunk extensors, and age. A stepwise selective multiple regression analysis for systolic pressure resulted in four significantly correlating variables: body fat percentage (p less than 0.001), heart rate (p less than 0.01), lean body mass (p less than 0.05), and strength of trunk extensors per kg body weight (p less than 0.05). For diastolic pressure the analysis resulted in two explaining variables: body mass index (p less than 0.001) and age (p less than 0.05). In a regression equation with 13 variables the strength of trunk flexors was negatively correlated with diastolic pressure. It is concluded that both fatness and muscularity are factors related to blood pressure in young men. The muscularity effect is more clearly associated with trunk and leg extensor strength.     

Soccer vs. running training effects in young adult men: which programme is more effective in improvement of body composition? Randomized controlled trial

The aims of this study were: 1) To determine the effects of a 12-week recreational soccer training programme and continuous endurance running on body composition of young adult men and 2) to determine which of these two programmes was more effective concerning body composition. Sixty-four participants completed the randomized controlled trial and were randomly assigned to one of three groups: a soccer training group (SOC; n=20), a running group (RUN; n=21) or a control group performing no physical training (CON; n=23). Training programmes for SOC and RUN lasted 12-week with 3 training sessions per week. Soccer sessions consisted of 60 min ordinary five-a-side, six-a-side or seven-a-side matches on a 30-45 m wide and 45-60 m long plastic grass pitch. Running sessions consisted of 60 min of continuous moderate intensity running at the same average heart rate as in SOC (~80% HR_max). All participants, regardless of group assignment, were tested for each of the following dependent variables: body weight, body height, body mass index, percent body fat, body fat mass, fat-free mass and total body water. In the SOC and RUN groups there was a significant decrease (p < 0.05) in body composition parameters from pre- to post-training values for all measures with the exception of fat-free mass and total body water. Body mass index, percent body fat and body fat mass did not differ between groups at baseline, but by week 12 were significantly lower (p < 0.05) in the SOC and RUN groups compared to CON. To conclude, recreational soccer training provides at least the same changes in body composition parameters as continuous running in young adult men when the training intensity is well matched.     

Body surface temperature distribution in relation to body composition in obese women

Adipose tissue levels and human obesity are known to be associated with increased heat production. At the same time, subcutaneous adipose tissue provides an insulating layer that impedes heat loss. The energy implications of obesity and body thermoregulatory mechanisms remain relatively poorly understood. This study attempted to examine the potential relationship between body composition (subcutaneous and visceral fat) determined by bioimpedance as well as BMI (body mass index), and skin surface temperature distribution recorded at rest.One specific aim of this study was to draw a thermal map of body areas in obese women and compare this with women of normal body mass, and thus to identify body regions within which heat transfer is particularly impeded. As high fat content is a good insulator, it could reduce the body‘s ability to respond effectively to changes in environmental temperature, which would be problematic for thermal homeostasis. Our results showed that core temperature did not differ between obese and normal body mass participants, while skin temperature of most body surfaces was lower in obese subjects.The results of regression analysis showed that the mean body surface temperature (T_mean) decreased with increasing percentage of body fat (PBF) of the abdominal area. The opposite relationship was observed for the front area of the hand (simultaneous increase in T_mean and PBF). We also found a negative correlation between BMI and T_mean of the thigh areas, both the front and the back. From this it could be concluded that the mean body surface temperature is dependent on body fat.     

海南临高人身体成分分析

2014年11月在海南省临高县测量了415例(男性为211例,女性为204例)临高人的体重、身高及体成分指标值。临高人男性体重、身高、总肌肉量、四肢肌肉量、躯干肌肉量、推定骨量、总能量代谢、水分率、内脏脂肪等级都大于女性,但总体脂率、躯干及四肢脂肪率则小于女性。随年龄增长,临高男性总体脂率、内脏脂肪等级、躯干脂肪率呈线性上升,而身高、总肌肉量、推定骨量、总能量代谢、躯干肌肉量呈线性下降。男性躯干部位的脂肪逐渐堆积,这导致临高男性总脂肪率、内脏脂肪等级、躯干脂肪率与年龄呈显著线性正相关。随年龄增长,临高女性总体脂率、总肌肉量、BMI、内脏脂肪等级、身体大部分部位的脂肪率、四肢肌肉量都呈线性增长(P<0.05或P<0.01)。女性的躯干和四肢脂肪率共同增加导致总脂肪率的增大,四肢肌肉量的增加导致总肌肉量的增大。临高男性体脂不发达,体脂率小于邻近汉族。临高人体脂发育情况与黎族较为接近。临高人肌肉较为发达。     

Pedometer-determined physical activity among obese and non-obese 8- to 12-year-old Saudi schoolboys

Physical activity levels were measured in obese and non-obese 8- to 12- year-old schoolboys (n=296). Anthropometric measures included weight, height, body mass index (BMI), triceps and subscapular skinfolds, predicted fat percentage, fat mass (FM), fat-free mass (FFM), FM index (FMI), and FFM index (FFMI). Physical activity was assessed using an electronic pedometer for three continuous weekdays. Boys were divided into active and inactive groups based on daily accumulation of pedometer counts above or below 13,000 steps. Obesity was defined as body fat content that equals or exceeds 25% of body weight. The international age- and gender-specific child BMI cut-off points were also used to define overweight and obesity. Estimated fat content for the whole sample averaged 23.3+/-9.7%. More than 37% of the boys were classified as obese. The mean step counts were about 13,489+/-5,791 steps per day (range: 335-29,169 steps). Over 71% of the boys accumulated 10,000 steps or more per day. Based on BMI standards, mean step counts for the obese group (10,602+/-4,800 steps/day) were significantly (p=0.004) lower than in the normal group (14,271+/-5,576 steps/day). Based on fat percentage, obese boys also accumulated significantly (p=0.009) lower numbers of steps per day (12,682+/-5,236) than did non-obese boys (14,915+/-5,643). Further, there were significant differences (p<0.05) between active and inactive boys in weight, BMI, triceps and subscapular skinfolds, fat percentage, FMI, and flexibility. It is concluded that the prevalence of obesity and inactivity among Saudi boys aged 8-12 years was high. Active boys exhibited significantly lower body fat percentage and BMI than inactive peers. Obese boys, on the other hand, were significantly less active than non-obese boys. Increased prevalence of obesity and physical inactivity among Saudi children is a major public health concern.     

A pilot crossover study: effects of an intervention using an activity monitor with computerized game functions on physical activity and body composition

Background

Wearing an activity monitor as a motivational tool and incorporating a behavior-based reward system or a computerized game element might have a synergistic effect on an increase in daily physical activity, thereby inducing body fat reduction. This pilot crossover study aimed to examine the effects of a short-term lifestyle intervention using an activity monitor with computerized game functions on physical activity and body composition.

Methods

Twenty healthy volunteers (31 ± 3 years) participated in a 12-week crossover study. The participants were randomly assigned to either Group A (a 6-week game intervention followed by a 6-week normal intervention) or Group B (a 6-week normal intervention followed by a 6-week game intervention). The participants wore both a normal activity monitor (Lifecorder EX) and an activity monitor with computerized game functions (Yuuhokei) during the game intervention, whereas they only wore a normal activity monitor during the normal intervention. Before, during, and after the intervention, body composition was assessed.

Results

Significantly more daily steps were recorded for the game intervention than for the normal intervention (10,520 ± 562 versus 8,711 ± 523 steps/day, P < 0.01). The participants performed significantly more physical activity at an intensity of ≥ 3 metabolic equivalents (METs) in the game intervention than in the normal intervention (3.1 ± 0.2 versus 2.4 ± 0.2 METs · hour/day, P < 0.01). Although body mass and fat were significantly reduced in both periods (P < 0.01), the difference in body fat reduction was significantly greater in the game intervention than in the normal intervention (P < 0.05).

Conclusions

A short-term intervention using an activity monitor with computerized game functions increases physical activity and reduces body fat more effectively than an intervention using a standard activity monitor.     

The effect of body fat percentage and body fat distribution on skin surface temperature with infrared thermography

This study aimed to search for relations between body fat percentage and skin temperature and to describe possible effects on skin temperature as a result of fat percentage in each anatomical site. Women (26.11±4.41 years old) (n =123) were tested for: body circumferences; skin temperatures (thermal camera); fat percentage and lean mass from trunk, upper and lower limbs; and body fat percentage (Dual-Energy X-Ray Absorptiometry). Values of minimum (T_Mi), maximum (T_Ma), and mean temperatures (T_Me) were acquired in 30 regions of interest. Pearson's correlation was estimated for body circumferences and skin temperature variables with body fat percentage. Participants were divided into groups of high and low fat percentage of each body segment, of which T_Me values were compared with Student's t-test. Linear regression models for predicting body fat percentage were tested. Body fat percentage was positively correlated with body circumferences and palm temperatures, while it was negatively correlated with most temperatures, such as T_Ma and T_Me of posterior thighs (r =−0.495 and −0.432), T_Me of posterior lower limbs (r =−0.488), T_Ma of anterior thighs (r =−0.406) and T_Mi and T_Me of posterior arms (r =−0.447 and −0.430). Higher fat percentages in the specific anatomical sites tended to decrease T_Me, especially in posterior thighs, shanks and arms. Skin temperatures and body circumferences predicted body fat percentage with 58.3% accuracy (R =0.764 and R² =0.583). This study clarifies that skin temperature distribution is influenced by the fat percentage of each body segment.     

The association between benzo[a]pyrene-DNA adducts and body mass index,calorie intake and physical activity

Prior work suggests that body size and fat content may influence carcinogen-DNA adduct levels measured in white blood cells. Here we consider energy balance more broadly by assessing the impact of body mass index (BMI), physical activity and calorie intake on the presence of benzo[a]pyrene-DNA (BP-DNA) adducts in white blood cell DNA. Our cross-sectional study employed subjects from a separately conducted intervention trial. Physical activity and food intake data were collected at 12 and 15 months of follow-up, respectively. BP-DNA adducts were measured by high-performance liquid chromatography (HPLC) in white blood cell samples collected at 12 months of follow-up. Complete data on all variables were available from 143 subjects. Logistic regression showed that BMI was inversely associated with the presence of detectable adducts (OR = 0.90, p=0.02), and that hours of moderate-intensity physical activity were positively associated with the presence of detectable adducts (OR = 1.04, p=0.04). These results provide further evidence that body fat content influences carcinogen-DNA adduct levels, probably by altering the distribution of the lipophilic parent compound.     

The association between benzo[a]pyrene-DNA adducts and body mass index, calorie intake and physical activity

Prior work suggests that body size and fat content may influence carcinogen-DNA adduct levels measured in white blood cells. Here we consider energy balance more broadly by assessing the impact of body mass index (BMI), physical activity and calorie intake on the presence of benzo[a]pyrene-DNA (BP-DNA) adducts in white blood cell DNA. Our cross-sectional study employed subjects from a separately conducted intervention trial. Physical activity and food intake data were collected at 12 and 15 months of follow-up, respectively. BP-DNA adducts were measured by high-performance liquid chromatography (HPLC) in white blood cell samples collected at 12 months of follow-up. Complete data on all variables were available from 143 subjects. Logistic regression showed that BMI was inversely associated with the presence of detectable adducts (OR = 0.90, p=0.02), and that hours of moderate-intensity physical activity were positively associated with the presence of detectable adducts (OR = 1.04, p=0.04). These results provide further evidence that body fat content influences carcinogen-DNA adduct levels, probably by altering the distribution of the lipophilic parent compound.     

Physical activity and body functionality: implications for obesity prevention and treatment

Physical activity promotes metabolic adaptations that improve body functionality and contribute to the prevention of some diseases. With respect to energy and fat balance, physical activity facilitates the equilibrium between energy intake and expenditure as well as between fat intake and fat oxidation. When combined with a healthy diet that favors satiety with a reduced energy intake, exercise can induce a substantial mass loss in obese individuals. However, even the impact of an exemplary lifestyle does not seem to have the potential to decrease body mass in obese individuals down to the mass range of lean people. Up to now, we have not been able to induce mass changes exceeding 12%-15% initial body mass in obese male subjects under tolerable exercise and dietary habits, and this moderate success was accompanied by modifications in appetite and energy expenditure susceptible to compromise subsequent mass stability. As described in this paper, many environmental factors can influence energy balance and the ability to lose body fat in response to a healthy diet and (or) physical activity program. Particular attention is given to preliminary data obtained in our laboratory that suggest that knowledge-based work does not favor the same potential mass reducing effects as physical work. In fact, the acute effects of knowledge-based work suggest that this work modality may be rather susceptible to promote a more pronounced positive energy balance compared with what we may expect from a sedentary relaxing activity. This is problematic for obesity prevention in the future since knowledge-based work now represents the main working modality in a context of modernity.     

Physical Activity as a Predictor of Body Composition in American Indian Children

Objective: To examine physical activity in second grade American Indian children as a predictor of percentage body fat 3 years later. Research Methods and Procedures: Physical activity was assessed as average vector magnitude (AVM) counts from an accelerometer in 454 second grade children as part of the Pathways study. BMI was assessed, and skinfolds and bioelectrical impedance were used to estimate fat mass, fat‐free body mass, and percentage body fat in validated prediction equations. Associations were examined using mixed models regression controlling for baseline body composition. Results: In normal‐weight children, higher AVM counts were significantly associated with decreases in percentage body fat. Among overweight children, higher AVM counts were significantly associated with increases in BMI, fat mass, and fat‐free mass but not percentage body fat. Discussion: Higher physical activity levels in second grade were associated with lower levels of percentage body fat in fifth grade in normal‐weight but not in overweight children. BMI showed no association with physical activity among normal‐weight children, and increases in BMI were associated with increasing amounts of physical activity among overweight children. These findings emphasize the importance of valid body composition measures and may indicate important differences in associations between physical activity and adiposity in normal‐weight as compared with overweight children.     

湖南、湖北、贵州土家族成人的体成分比较

体成分指的是身体脂肪、蛋白质、肌肉、水等含量在体质量中所占的百分比.各成分之间的合理比例,对于维持机体的正常运行,十分重要.因此身体成分的研究一直是国内外研究的热点.体成分存在着人种和民族差异,因此它也是人类学研究的重要课题.目前的研究主要集中在中国青少年、大学生的体成分及体成分与其他身体指标的关系,而对于土家族的研究...     

Pedometer-determined physical activity and indicators of health in Japanese adults

Recently, many cross-sectional studies observed that body mass index (BMI) and percentage of body fat (%BF) were inversely associated with pedometer-determined physical activities, but studies on Asian populations, including the Japanese, are sparse. Height, weight, body fat percentage (%BF, bioelectrical impedance analyzer), and waist circumference were measured on 117 women (62.8+/-4.5 years, 22.2+/-2.2 kg/m(2)) and 62 men (64.0+/-4.6 years, 23.6+/-2.5 kg/m(2)). Pearson correlations and partial correlation coefficients after controlling for age were calculated between steps/day and variables. Furthermore, participants were classified into four groups as follows: <5,000, 5,000-7,499, 7,500-9,999, and >or=10,000 steps/day, and analyzed using ANOVA across activity groups. In women, a significant correlation was found between steps/day and BMI (r=-0.217, p=0.018), %BF (r=-0.292, p=0.0014), and the relationship was still significant after controlling for age. The relationship between steps/day and waist circumference was not significant. In men, a significant relationship was not observed between steps/day and obesity indices. The correlations between steps/day and both BMI and %BF were significant in Japanese women, but weak compared with Caucasian and African-American women as reported previously. A possible cause is racial difference in degree of obesity and body shape. The effects of physical activity on body shape and composition may differ according to race.     

Changes over four years in body composition and oxygen uptake of young adult males after university graduation

Lifestyle changes and challenges following university graduation often present a sharp contrast to the relatively free and basically pleasant university life enjoyed by the typical college student. Adaptation to a new work environment, relocation to a new community, concerns of marriage and family, personal finances, including income and budgeting (automobile and mortgage payments, savings, etc.), and adjustment to independent living result in an unfamiliar schedule of duties, often too sedentary in nature.The aim of this study was to analyse the changes observed in young working professionals by comparing selected body composition estimates, and physiological working capacity variables at the time of university graduation and four years later.Anthropometric and functional cardio-respiratory exercise test data were collected in 26 physically active (but non-athletic) volunteer males at the time of their university graduation in 2000 and 4 years later in 2004. By the end of this four-year period body weight, body mass index (BMI), the sum of 5 skinfold thicknesses, and relative body fat content increased significantly. Both mean BMI and weight-related body fat content were within the categorized risk range at the time of the second data collection. Parallel with unfavourable changes in body composition, peak minute ventilation, aerobic power, oxygen pulse, and maximum treadmill running distance had decreased significantly during this time. We attributed the significant changes observed mainly to the dramatically changed lifestyle. The subjects could not maintain their previous level of habitual physical activity.