Body weight, body image, and eating behaviours : relationships with ethnicity and acculturation in a community sample of young Australian women

A study was conducted to investigate associations between ethnicity and acculturation status and risk factors for eating disorders among young adult women. A community sample of 14,779 women aged 18–23 completed a comprehensive mail-out survey, which incorporated questions on country of birth, length of time spent in Australia, body weight, weight dissatisfaction, dieting, binge eating, and compensatory disordered eating behaviours. Results showed that risk factors for eating disorders were present across a range of ethnic groups. Further, a strong acculturation effect was observed, such that the longer the time spent in Australia, the more women reported weight-related values and behaviours similar to those of Australian-born women. Results challenge claims that risk factors for disordered eating are restricted to Caucasian females in Western societies. Implications for understanding ethnic and sociocultural influences on body weight, dieting, and disordered eating are considered.

Overweight children have poor bone strength relative to body weight, placing them at greater risk for forearm fractures

Introduction: Obesity is thought to be a protective factor for bones in adults but not in children based on the evidence of the greater incidence of forearm fractures in obese children. Our objective was to investigate the effect of adiposity on bone strength in relation to the mechanical challenge placed onto the forearm bones in case of a fall.

Methods: Cross sectional areas (CSA) were obtained at the mid- and distal radius by peripheral quantitative computed tomography in 486 children (241 boys), mean age 8.3 years (range 6.9–9.7), participating in the LOOK Project. The following parameters were measured: bone mass and bone CSA (both sites), and muscle and fat CSA (mid-forearm only). Bone strength indices combining bone size and total volumetric density were calculated at each site.

Results/Discussion: Overweight children (BMI > percentile equivalent to 25 kg/m² in adults) have higher bone parameters than normal-weight peers (Z-scores +0.6 to +0.9SD, p < 0.0001). These differences disappear after adjustment for muscle CSA. Adiposity (fat CSA/muscle CSA) was negatively correlated with bone mass, size and strength at the distal radius only (r = −0.1, p < 0.05). After adjustment for body weight (estimate of the load during a fall), the negative correlations were stronger and observed at both the mid- and distal radius (r = −0.37 to −0.55, p < 0.0001).

Conclusion. Overweight children have stronger bones due to greater muscle size. However, children with high fat mass relative to muscle mass (increased adiposity) have poorer bone strength, independent of weight, which may contribute to the increased risk of fracture in obese children.

Women's work. Maintaining a healthy body weight

This study describes women's perceptions of the supports and barriers to maintaining a healthy weight among currently healthy weight women from urban and rural socio-economically disadvantaged areas. Using focus groups and interviews, we asked women about their experiences of maintaining a healthy weight. Overwhelmingly, women described their healthy weight practices in terms of concepts related to work and management. The theme of ‘managing health’ comprised issues of managing multiple responsibilities, time, and emotions associated with healthy practices. Rural women faced particular difficulties in accessing supports at a practical level (for example, lack of childcare) and due to the gendered roles they enacted in caring for others. Family background (in particular, mothers’ attitudes to food and weight) also appeared to influence perceptions about healthy weight maintenance. In the context of global increases in the prevalence of obesity, the value of initiatives aimed at supporting healthy weight women to maintain their weight should not be under-estimated. Such initiatives need to work within the social and personal constraints that women face in maintaining good health.

Effects of diets high in whey, soy, red meat and milk protein on body weight maintenance in diet-induced obesity in mice

This study examined the effects of different food sources of protein on energy intake, body weight maintenance, and on the responses of plasma leptin, insulin and adiponectin in chronic high-fat diet-induced obese mice. Obesity was induced in 47 mice with a high-fat diet for 20 weeks. They were divided into five diet groups to test the effects of a higher protein proportion (30% energy), achieved at the expense of carbohydrate. For the next eight weeks, four of the groups were fed diets of chow formulated with whey, soy, red meat or milk while the control group continued on their high-fat diet. The results showed that: (i) increasing the protein : carbohydrate ratio (both at 30% energy) in a high-fat diet did not reduce the level of obesity; (ii) the type of protein added, however, did have a significant effect on the level of obesity attained; (iii) whey protein stabilised weight gain the most, had the strongest satiety effects and also stimulated the highest production of adiponectin; and (iv) whey protein also was associated with the lowest insulin values among all proteins tested. Plasma leptin levels were not affected by any of the diets. Dietary fat remains a potent factor in weight management, but the type and amount of protein may also be important through its effects on food intake. In particular, the apparent decreased appetite associated with increased adiponectin in the whey-based high-protein diet may contribute to stabilised body mass in chronic high-fat diet-induced obesity.

Novel hypothalamic genes involved in body weight regulation in Psammomys obesus

Focuses on the discovery, characterisation and validation of a gene in the brain, named FIT, that regulates body weight. When suppressed in rats, food intake is inhibited and body weight is reduced. FIT regulates both appetite and metabolic rate, and is therefore a new and exciting target for obesity therapy.

Body weight and weight loss : are health messages reaching their target?

Objective: To investigate lay peoples’ knowledge of health risks of overweight, accuracy of self-perception of body weight and perceived benefits of weight loss. Method: A nine item questionnaire was administered to a cross sectional survey of adults in metropolitan shopping centres, height and weight were measured. Results: Two hundred and nine (57% female) adults completed the survey. Thirty eight percent had a healthy BMI (18.5-24.9), 38% were overweight (BMI 25-29.9) and a further 22% were obese (BMI>30). However only 46% perceived themselves ‘overweight’, 50% considered themselves ‘just about right’ and 4% considered themselves ‘underweight’. Of those with a BMI of 25 or greater 28% considered their weight ‘just about right’. Over 80% thought ‘being overweight’ was ‘likely’ or ‘very likely’ to be a risk factor for cardiovascular disease, hypertension, diabetes and stroke; however 20% of overweight or obese individuals did not think their health would improve if they lost weight. Conclusion: A significant proportion of overweight or obese individuals do not accurately perceive their body weight and do not recognise the health advantages of weight loss despite recognising excess body weight as a risk factor for chronic diseases. Implications: Increasing the awareness of an individual’s BMI and promoting the benefits of modest weight loss maybe two underutilized strategies for population level weight control.

The attractive female body weight and female body dissatisfaction in 26 countries across 10 world regions : results of the international body project 1

This study reports results from the first International Body Project (IBP-I), which surveyed 7,434 individuals in 10 major world regions about body weight ideals and body dissatisfaction. Participants completed the female Contour Drawing Figure Rating Scale (CDFRS) and self-reported their exposure to Western and local media. Results indicated there were significant cross-regional differences in the ideal female figure and body dissatisfaction, but effect sizes were small across highsocioeconomic-status (SES) sites. Within cultures, heavier bodies were preferred in low-SES sites compared to high-SES sites in Malaysia and South Africa (ds = 1.94-2.49) but not in Austria. Participant age, body mass index (BMI), and Western media exposure predicted body weight ideals. BMI and Western media exposure predicted body dissatisfaction among women. Our results show that body dissatisfaction and desire for thinness is commonplace in high-SES settings across world regions, highlighting the need for international attention to this problem.

Increased energy intake entirely accounts for increase in body weight in women but not in men in the UK between 1986 and 2000

There is debate over the casual factors for the rise in body weight in the UK. The present study investigates whether increases between 1986 and 2000 for men and women were a result of increases in mean total energy intake, decreases in mean physical activity levels or both. Estimates of mean total energy intake in 1986 and 2000 were derived from food availability data adjusted for wastage. Estimates of mean body weight for adults aged 19–64 years were derived from nationally representative dietary surveys conducted in 1986–7 and 2000–1. Predicted body weight in 1986 and 2000 was calculated using an equation relating body weight to total energy intake and sex. Differences in predicted mean body weight and actual mean body weight between the two time points were compared. Monte Carlo simulation methods were used to assess the stability of the estimates. The predicted increase in mean body weight due to changes in total energy intake between 1986 and 2000 was 4·7 (95 % credible interval 4·2, 5·3) kg for men and 6·4 (95 % credible interval 5·9, 7·1) kg for women. Actual mean body weight increased by 7·7 kg for men and 5·4 kg for women between the two time points. We conclude that increases in mean total energy intake are sufficient to explain the increase in mean body weight for women between 1986 and 2000, but for men, the increase in mean body weight is likely to be due to a combination of increased total energy intake and reduced physical activity levels.

Angiotensin converting enzyme inhibition lowers body weight and improves glucose tolerance in C57BL/6J mice maintained on a high fat diet

The renin–angiotensin system (RAS) is functional within adipose tissue and angiotensin II, the active component of RAS, has been implicated in adipose tissue hypertrophy and insulin resistance. In this study, captopril, an angiotensin converting enzyme (ACE) inhibitor that prevents angiotensin II formation, was used to study the development of diet-induced obesity and insulin resistance in obesity prone C57BL/6J mice. The mice were fed a high fat diet (w/w 21% fat) and allowed access to either water or water with captopril added (0.2 mg/ml). Body weight was recorded weekly and water and food intake daily. Glucose tolerance was determined after 11–12 weeks. On completion of the study (after 16 weeks of treatment), the mice were killed and kidney, liver, epididymal fat and extensor digitorum longus muscle (EDL) were weighed. Blood samples were collected and plasma analysed for metabolites and hormones. Captopril treatment decreased body weight in the first 2 weeks of treatment. Food intake of captopril-treated mice was similar to control mice prior to weight loss and was decreased after weight loss. Glucose tolerance was improved in captopril-treated mice. Captopril-treated mice had less epididymal fat than control mice. Relative to body weight, captopril-treated mice had increased EDL weight. Relative to control mice, mice administered captopril had a higher plasma concentration of adiponectin and lower concentrations of leptin and non-esterified fatty acids (NEFA). The results indicate that captopril both induced weight loss and improved insulin sensitivity. Thus, captopril may eventually be used for the treatment of obesity and Type 2 diabetes.

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.

Fructose containing sugars modulate mRNA of lipogenic genes ACC and FAS and protein levels of transcription factors ChREBP and SREBPIc with no effect on body weight or liver fat

The aim of this study was to determine the effects of high-glucose, high-fructose and high-sucrose diets on weight gain, liver lipid metabolism and gene expression of proteins involved with hepatic fat metabolism. Rats were fed a diet containing either 60% glucose, 60% fructose, 60% sucrose, or a standard chow for 28 days. Results indicated that high-fructose and high-sucrose diets were associated with higher mRNA levels of gene transcripts involved with fat synthesis; ACC, FAS and ChREBP, with no change in SREBP-1C mRNA. The protein level of ChREBP and SREBP1c was similar in liver homogenates from all groups, but were higher in nuclear fractions from the liver of high-fructose and high-sucrose fed rats. The mRNA level of gene transcripts involved with fat oxidation was the same in all three diets, whilst a high-fructose diet was associated with greater amount of mRNA of the fat transporter CD36. Despite the changes in mRNA of lipogenic proteins, the body weight of animals from each group was the same and the livers from rats fed high-fructose and high-sucrose diets did not contain more fat than control diet livers. In conclusion, changing the composition of the principal monosaccharide in the diet to a fructose containing sugar elicits changes in the level of hepatic mRNA of lipogenic and fat transport proteins and protein levels of their transcriptional regulators; however this is not associated with any changes in body weight or liver fat content.