Assessing body condition and energy budget components by scoring abdominal profiles in free-ranging pink-footed geese Anser brachyrhynchus

An abdominal profile index (API) was developed for pink-footed geese Anser brachyrhynchus as a measure of body condition. On basis of carcass analysis of 56 adult geese with known API prior to collection, we found significant linear relationships between API against body mass, abdominal fat and total energy content. Hence, changes in API reflect net energy intake rates. As an example of the applicability of the calibration, we compared APIs of individually marked geese before and after long migration episodes and estimated the cost of flight at 8.9 kJ/km. In addition we estimated gain rates at three major staging sites along the spring flyway indicating an increase in fueling rates with latitude. Calibration of APIs and energy contents offers new opportunities for field studies of waterfowl energetics.

Bipolar disorder and adiposity : a study using whole body dual energy X-ray absorptiometry scans

Objective: Previous research has demonstrated a relationship between adiposity and bipolar disorder, although data are derived predominantly from patient samples and use indirect methods of assessing adiposity. This study investigated the association between bipolar disorder and several indices of adiposity, including body fat mass as measured by dual energy X-ray absorptiometry (DXA), in a community-based sample.

Methods: In this study, 21 women with bipolar disorder and 523 healthy controls were drawn from an age-stratified, random, community-based sample of women (20–93 years) participating in the Geelong Osteoporosis Study. Bipolar disorder was diagnosed utilising a semi-structured clinical interview. Anthropometric measurements (weight, height, waist and hip circumference) were taken and fat mass was determined from whole body DXA scans (Lunar DPX-L).

Results: Those with bipolar disorder tended to have greater adiposity. Age-adjusted mean (95% CI) values for bipolar versus controls according to adiposity indices were weight 75.6 (68.9–82.3) versus 72.6 (71.3–74.0) kg, waist circumference 89.8 (84.1–95.6) versus 87.3 (86.1–88.5) cm, waist:hip ratio 0.85 (0.82–0.87) versus 0.84 (0.83–0.84), body mass index 27.6 (25.1–30.1) versus 27.5 (27.0–28.0) kg/m2, fat mass 31.4 (26.5–36.3) versus 28.6 (27.5–29.5) kg and %body fat 40.4 (36.9–43.9) versus 38.0 (37.3–38.7)%; all p > 0.05. Further adjustment for height, smoking, alcohol, psychotropic medication, energy intake or physical activity did not influence these patterns.

Conclusion: Although a pattern suggestive of greater adiposity among those with bipolar disorder was observed, no significant differences were detected. We cannot exclude the possibility of a type II error. Further research with a larger sample may produce more conclusive results.

Direction-specific diaphyseal geometry and mineral mass distribution of tibia and fibula: A pQCT study of female athletes representing different exercise loading types

Bones adapt to prevalent loading, which comprises mainly forces caused by muscle contractions. Therefore, we hypothesized that similar associations would be observed between neuromuscular performance and rigidity of bones located in the same body segment. These associations were assessed among 221 premenopausal women representing athletes in high-impact, odd-impact, highmagnitude, repetitive low-impact, and repetitive nonimpact sports and physically active referents aged 17–40 years. The whole group mean age and body mass were 23 (5) and 63 (9) kg, respectively. Bone cross sections at the tibial and fibular mid-diaphysis were assessed with peripheral quantitative computed tomography (pQCT). Density-weighted polar section modulus (SSI) and minimal and maximal crosssectional moments of inertia (Imin, Imax) were analyzed. Bone morphology was described as the Imax/Imin ratio. Neuromuscular performance was assessed by maximal power during countermovement jump (CMJ). Tibial SSI was 31% higher in the high-impact, 19% in the odd-impact, and 30% in the repetitive low-impact groups compared with the reference group (P\0.005). Only the high-impact group differed from the referents in fibular SSI (17%, P\0.005). Tibial morphology differed between groups (P = 0.001), but fibular morphology did not (P = 0.247). The bone-bygroup interaction was highly significant (P\0.001). After controlling for height, weight, and age, the CMJ peak power correlated moderately with tibial SSI (r = 0.31, P\0.001) but not with fibular SSI (r = 0.069, P = 0.313). In conclusion, observed differences in the association between neuromuscular performance and tibial and fibular traits suggest
that the tibia and fibula experience different loading

Insectivore life histories: further evidence against an optimum body size for mammals

1. This study tests a model of the relationship of body mass to reproductive power (the rate of conversion of energy from the environment to an organism’s offspring). Specifically tested is the prediction that the regression of life-history variables on body size will change slope and sign about an ‘optimum’ body mass of 100 g.
2. Life-history data from the mammalian order Insectivora have been collated and analysed using a phylogenetic comparative method to test this prediction.
3. The analyses showed little evidence for significant changes in slope or sign around 100 g body mass, or other possible optimal body masses, contradicting the predictions of the model. These findings agree with those of similar analyses on life-history variables of bats.

Body fat estimated from anthropometric and electrical impedance measurements

Estimates of body fat based on anthropometric measurements were compared in two groups of females, one from the local community and the other from the 1984 Australian Olympic Team. Estimates of body fat based on electrical impedance measurements were also made for the community group. For estimates of total body fat based on skinfold measurements, a significant difference of approximately 1 kg fat/m2 was observed between athletes and non-athletes. In the group of non-athletes estimates of fat based on skinfold measurements were significantly higher than those based on body mass index, with estimates from electrical impedance falling between. Electrical impedance measurements may provide a means of estimating body fat which takes into account differences in fat distribution and in the ratio of fat to fat-free tissue and may thus overcome the problems associated with estimates based on measurements of subcutaneous fat (skinfolds) or body size which do not allow for these differences.

The influence of body build on estimates of body composition from anthropometric measurements in premenopausal women

Objective: To assess the influence of body build on the bias and limits of agreement for estimates of body fat obtained from anthropometric prediction equations when compared with the same data obtained by dual energy X-ray absorptiometry (DEXA).

Survey design and subjects: Ninety-one premenopausal women, aged between 20 and 54 years, were chosen to represent a range of skeletal body build (relative silting height 0.50-0.56) and body fatness [body mass index (BMI) 18-34 kg/m²]. Measurements of weight, sitting height, stature, skinfold thickness, waist, umbilical and hip circumference and total body resistance and reactance were made on all subjects by standard techniques after an overnight fast. A DEXA measurement of total body fat, fat-free soft tissue and total body bone mineral mass was also obtained within 2 weeks of the anthropometric assessment.

Results: At the group level the mean difference (bias) between DEXA and the anthropometric estimates of body fat was similar for all three anthropometric estimates ranging from 2.7 kg with impedance to 1.8 kg with skinfold thickness. The 95% limits of agreement were also similar, ranging from ±5.3 kg with body mass index to ±4.1 kg with impedance. Umbilical circumference, BMI and the amount of bone mineral expressed as a proportion of the fat-free soft-tissue mass were all significantly (P < 0.01) correlated with the level of bias between DEXA and the anthropometric estimates of body fat. This was not the case for relative sitting height or measures of body fat distribution. Regression equations which included BMI or umbilical circumference in combination with the predicted estimates of body fat essentially eliminated the association between the level of bias in predicted body fat and the level of body fatness. They also reduced the 95% limits of agreement between DEXA and the anthropometric estimates of body fat.

Conclusions: Using DEXA estimates of body fat as the standard of reference our results suggest that the comparability and precision of body fat estimates derived from age- and/or sex-specific anthropometric prediction equations based on skinfolds and BMI, but not impedance, can be improved by adjusting for differences in BMI and umbilical circumference respectively.

Relationship of serum leptin to total and truncal body fat

1. In this study we investigated the relationship between serum leptin levels and body fat distribution in a random sample of women of widely ranging age and body mass index. Anthropometry and dual energy X-ray absorptiometry were used to measure body fat and its distribution.

2. Leptin levels (log transformed) were not significantly correlated with age, but were significantly positively correlated (P < 0.001) with most anthropometric measures except waist-to-hip circumference ratio. The strongest correlations were with total grams of body fat and percentage body fat (r = 0.68 and 0.76 respectively, P < 0.001). When corrected for percentage body fat the partial correlation coefficients for all other measures became non-significant. The correlation with truncal body fat fell significantly from 0.66 to - 0.05 after correction, but the partial correlation with total body fat remained significant (P < 0.005) when grams of truncal fat were controlled for (r = 0.21).

3. These results indicate that the relationship of serum leptin to percentage body fat is the strongest, and that truncal body fat, although the most metabolically active, does not appear to have an independent association with serum leptin.

Methodological problem with comparing increases in different measures of body weight

Background A number of studies have compared proportional increases over time in waist circumference (WC) and body mass index (BMI). However this method is flawed. Here, we explain why comparisons of WC and BMI must take into account the relationship between them. We used data from two cross-sectional US surveys (NHANES 1988-94 and 2005-06), and calculated the percentage change in the average BMI and the average WC between the two surveys, comparing the results with a regression analysis of changes in WC relative to BMI.

Findings The crude percentage change in BMI (5.8%) was marginally greater than for WC (5.1%). But these percentages cannot be directly compared, as the relationship between the measures is described by a regression equation with an intercept term that does not equal zero. The coefficient of time from the regression equation will determine whether or not WC is on average larger for a given BMI at the second compared with the first time point.

Conclusion Differences in the percentage change in WC and the percentage change in BMI cannot be usefully directly compared. Comparisons of increases in the two measures must account for the relationship between them as described by the regression equation.

Body image and self-esteem among Asian, Pacific Islander, and white college students in Hawaii and Australia

Body image and its relationship to self-esteem was examined among Asian, Pacific Islander, and White women and men from Hawaii and Australia (n = 172). Although Pacific Islander and White participants had higher body mass indices than Asians, Pacific Islanders were more satisfied than Asians with their health and more satisfied than Asians and Whites with their appearance. Thus, higher body weight and greater body satisfaction may co-occur among Pacific Islanders, whereas lower weight and lower body satisfaction may co-occur among Asians. The findings suggest different levels of risk for body image dissatisfaction, and its associated psychological consequences, across ethnic groups.

A re-examination of the benefits of exercise for state body satisfaction: Considerationof individual difference factors

Although the link between exercise and body image is well documented, the considerable inter-individual variability in this relationship has been largely ignored. Therefore, the aim of the present study was to test the contributions of key body image and exercise-related moderators (age, body mass index (BMI), exercise frequency, trait body dissatisfaction, internalisation of appearance standards, and body surveillance tendencies) in predicting variability in the exercise-body satisfaction relationship. Thirty-seven undergraduate women completed a questionnaire containing the above trait-based measures and then carried a Personal Digital Assistant (PDA) for a 7-day period. Participants were instructed to use the PDA to self-report their state body satisfaction immediately following an exercise session and also when the PDA signalled at each of six random intervals throughout the day. Multilevel modelling revealed a bi-directional relationship between exercise and state body satisfaction. Moreover, post-exercise increases in state body satisfaction were strongest for individuals who were younger and engaged in regular exercise, and weakest for individuals with high BMI and/or the tendency to compare their appearance with others. These findings highlight potential limits on the efficacy of exercise-based therapy for body image disturbances.

Genetic variation in SH3-domain GRB2-like (endophilin)-interacting protein 1 has a major impact on fat mass

Objective:

The SH3-domain GRB2-like (endophilin)-interacting protein 1 (SGIP1) gene has been shown to be differentially expressed in the hypothalamus of lean versus obese Israeli sand rats (Psammomys obesus), and is suspected of having a role in regulating food intake. The purpose of this study was to assess the role of genetic variation in SGIP1 in human disease.
Subjects:

We performed single-nucleotide polymorphism (SNP) genotyping in a large family pedigree cohort from the island of Mauritius. The Mauritius Family Study (MFS) consists of 400 individuals from 24 Indo-Mauritian families recruited from the genetically homogeneous population of Mauritius. We measured markers of the metabolic syndrome, including diabetes and obesity-related phenotypes such as fasting plasma glucose, waist:hip ratio, body mass index and fat mass.
Results:

Statistical genetic analysis revealed associations between SGIP1 polymorphisms and fat mass (in kilograms) as measured by bioimpedance. SNP genotyping identified associations between several genetic variants and fat mass, with the strongest association for rs2146905 (P=4.7 × 10−5). A strong allelic effect was noted for several SNPs where fat mass was reduced by up to 9.4% for individuals homozygous for the minor allele.
Conclusions:

Our results show association between genetic variants in SGIP1 and fat mass. We provide evidence that variation in SGIP1 is a potentially important determinant of obesity-related traits in humans.

Alcohol consumption and body composition in a population-based sample of elderly Australian men

Background: Alcohol is calorie dense, and impacts activity, appetite and lipid processing. The aim of this study was to therefore investigate the association between alcohol consumption and components of body composition including bone, fat and lean tissue.

Methods: Participants were recruited from a randomly selected, population-based sample of 534 men aged 65 years and older enrolled in the Geelong Osteoporosis Study. Alcohol intake was ascertained using a food frequency questionnaire and the sample categorised as nondrinkers or alcohol users who consumed B2, 3–4 or C5 standard drinks on a usual drinking day. Bone mineral density (BMD), lean body mass and body fat mass were measured using dual energy X-ray absorptiometry; overall adiposity (%body fat), central adiposity (%truncal fat) and body mass index (BMI) were calculated. Bone quality was determined by quantitative heel ultrasound (QUS).

Results: There were 90 current non-drinkers (16.9 %), 266 (49.8 %) consumed 1–2 drinks/day, 104 (19.5 %) 3–4 drinks/day and 74 (13.8 %) C5 drinks/day. Those consuming C5 drinks/day had greater BMI (?4.8 %), fat mass index (?20.1 %), waist circumference (?5.0 %), %body fat (?15.2 %) and proportion of trunk fat (?5.3 %) and lower lean mass (-5.0 %) than non-drinkers after adjustment for demographic and lifestyle factors. Furthermore, they were more likely to be obese than non-drinkers according to criteria based on BMI (OR = 2.83, 95 %CI 1.10–7.29) or waist circumference (OR = 3.36, 95 %CI 1.32–8.54). There was an inverse relationship between alcohol consumption and QUS parameters and BMD at the mid forearm site; no differences were detected for BMD at other skeletal sites.

Conclusion: Higher alcohol intake was associated with greater total and central adiposity and reduced bone quality.

Stress-induced rise in body temperature is repeatable in free-ranging Eastern chipmunks (Tamias striatus)

In response to handling or other acute stressors, most mammals, including humans, experience a temporary rise in body temperature (T b). Although this stress-induced rise in T b has been extensively studied on model organisms under controlled environments, individual variation in this interesting phenomenon has not been examined in the field. We investigated the stress-induced rise in T b in free-ranging eastern chipmunks (Tamias striatus) to determine first if it is repeatable. We predicted that the stress-induced rise in T b should be positively correlated to factors affecting heat production and heat dissipation, including ambient temperature (T a), body mass (M b), and field metabolic rate (FMR). Over two summers, we recorded both T b within the first minute of handling time (T b1) and after 5 min of handling time (T b5) 294 times on 140 individuals. The mean ∆T b (T b5 – T b1) during this short interval was 0.30 ± 0.02°C, confirming that the stress-induced rise in T b occurs in chipmunks. Consistent differences among individuals accounted for 40% of the total variation in ∆T b (i.e. the stress-induced rise in T b is significantly repeatable). We also found that the stress-induced rise in T b was positively correlated to T a, M b, and mass-adjusted FMR. These results confirm that individuals consistently differ in their expression of the stress-induced rise in T b and that the extent of its expression is affected by factors related to heat production and dissipation. We highlight some research constraints and opportunities related to the integration of this laboratory paradigm into physiological and evolutionary ecology.

State body dissatisfaction and social interactions : an experience sampling study

To date, there has been limited empirical scrutiny of the correlates and consequences of day-to-day state body dissatisfaction fluctuations within naturalistic contexts. We used ecological momentary assessment (a form of naturalistic observation) to evaluate whether state body dissatisfaction was concurrently and/or prospectively associated with occurrence and quality of social interactions. Women (N = 121), aged 18 to 40, completed a brief trait-based survey and then nominated a 7-day period within which to receive seven text messages daily, at random intervals, prompting them to complete measures of body dissatisfaction at that moment. If they were currently or had recently engaged in social interactions, they were also asked to fill out questions rating the quality of these interactions (operationalized in terms of enjoyment of, and control in, the interaction). Findings suggest that the relationship between state body dissatisfaction and aspects of social interactions is complex and may vary over time. Cross-sectionally, state body dissatisfaction and social interaction quality were negatively associated. Prospectively, however, body dissatisfaction predicted subsequent avoidance of social interactions. Interestingly, when women chose to avoid social interactions, their body dissatisfaction worsened, yet when they did engage in social interactions, they reported improved body satisfaction. Importantly, the links between state body dissatisfaction and social interactions may be moderated by body mass index and trait body satisfaction levels. Potential mechanisms underlying the association between state body dissatisfaction and quality and quantity of social interactions are discussed, and future research avenues are proposed to further understand their inter-relation.

Effect of changes to the school food environment on eating behaviours and/or body weight in children: a systematic review

Previous school obesity-prevention reviews have included multi-component interventions. Here, we aimed to review the evidence for the effect of isolated food environment interventions on both eating behaviours (including food purchasing) and/or body weight. Five electronic databases were searched (last updated 30 November 2013). Of the 1,002 unique papers identified, 55 reported on school food environment changes, based on a review of titles and abstracts. Thirty-seven further papers were excluded, for not meeting the inclusion criteria. The final selection consisted of 18 papers (14 United States, 4 United Kingdom). Two studies had a body mass index (BMI) outcome, 14 assessed purchasing or eating behaviours and two studies assessed both weight and behaviour. Seventeen of 18 papers reported a positive outcome on either BMI (or change in BMI) or the healthfulness of food sold or consumed. Two studies were rated as strong quality and 11 as weak. Only three studies included a control group. A school environment supportive of healthy eating is essential to combat heavy marketing of unhealthy food. Modification of the school food environment (including high-level policy changes at state or national level) can have a positive impact on eating behaviours. A need exists, however, for further high-quality studies.