Clinically, gross obesity is associated with disturbances of ventilatory function, but less severe obesity is not generally thought to have a significant effect on ventilatory function. The purpose of this report was to examine cross-sectional data to determine the effects of body composition and fat distribution on ventilatory function in 1235 adults (621 men and 614 women). Forced vital capacity (FVC) was used as a measure of ventilatory function and was adjusted for age, height, smoking, and bronchial symptoms in separate models for men and women. Body fat and fat-free mass were estimated from skinfold-thickness measurements. Adjusted FVC was not significantly associated with body mass or body mass index, but was negatively associated with percentage body fat in men (P = 0.0003) and women (P = 0.043) and positively associated with fat-free mass in men (P = 0.018) and women (P = 0.0001). Handgrip strength was positively associated with adjusted FVC in both sexes (P < 0.02), suggesting that the effect of fat-free mass may be mediated by muscular strength. Adjusted FVC was negatively associated with subscapular-skinfold thickness in both sexes (P < 0.0003) and with waist circumference (P = 0.01) and waist-to-hip ratio (P = 0.03) in men. Previous reports that considered only body mass index or body mass failed to distinguish the opposing effects of fat-free mass and fat mass on FVC.

OBJECTIVE: Body mass index (BMI) based on self-reported height and weight is a systematically biased, but acceptable measure of adiposity and is commonly used in population surveys. Recent studies indicate that abdominal obesity is more strongly associated with obesity-related health problems than is adiposity measured by BMI. The purpose of this study was to determine the relationships of both measured and self-reported BMI with measured waist circumference in a randomly selected sample of Australian adults. DESIGN: Cross-sectional survey with self-reported and laboratory-based measures of adiposity. SUBJECTS: 1140 randomly-selected Australian adults aged 18 ± 78 y resident in the city of Adelaide, South Australia. MEASUREMENTS: Data on self-reported and measured height and weight as well as measured waist circumference were drawn from the Pilot Survey of the Fitness of Australians database. The proportion of men and women with acceptable BMI (BMI 25 kgam 2 ) and with excess abdominal adiposity ( ! 94 cm for men and ! 80 cm for women) was determined. Differences in the prevalence of overweight based on BMI alone or BMI and waist circumference were also determined. RESULTS: Compared with the prevalence based on self-reported BMI alone, the prevalence of overweight among men based on self-reported BMI and waist circumference combined was 2.4%, 5.3%, 19.1% and 7.5% greater for men aged 18 ± 39 y, 40 ± 59 y, 60 ± 78 y and for all men, respectively. Among women, compared with the prevalence based on selfreported BMI alone, the prevalence of overweight based on the combined measures was 9.9%, 24.0%, 33.3% and 20.6% greater for women aged 18 ± 39 y, 40 ± 59 y, 60 ± 78 y and for all women, respectively. CONCLUSIONS: If waist circumference is used as the criterion, then the prevalence of overweight among Australian adults, and probably other Caucasian populations, may be signi®cantly greater than indicated by surveys relying on self-reported height and weight. The development of valid self-reported measures of waist circumference for use in population surveys may allow more accurate epidemiological monitoring of overweight and obesity.

BACKGROUND: Obesity in childhood and adolescence is associated with health problems, increases in cardiovascular disease (CVD) risk factors and a greater likelihood of becoming overweight as an adult. A description of the sociodemographic distribution of overweight and obesity among children and adolescents in the population may allow us to determine if health promotion resources should be differentially allocated to particular groups. METHODS: The New South Wales Schools Fitness and Physical Activity Survey, 1997 (n 5518) was a cross-sectional survey which measured height, weight, waist and hip girths and skinfold thicknesses of randomly selected New South Wales students in school years 4, 6, 8 and 10. Height and weight only were measured among Year 2 students. The mean ages of students in school years 2, 4, 6, 8 and 10 were 7.3 y, 9.3 y, 11.3 y, 13.3 y and 15.3 y, respectively. The values of body mass index (BMI), waist girth, waist-to-hip ratio (WHR) and sum of three skinfolds for students resident in urban and rural areas and in tertiles of socioeconomic status (SES) were compared. RESULTS: There were no differences on any of the anthropometric measures between urban and rural boys and girls, with the exception that WHR was higher among urban girls. Among boys, there were no differences between the SES tertiles on any of the measures. Among girls, each of the anthropometric measures (except sum of skinfolds) was inversely associated with SES, with body fatness tending to be lower in the high SES tertile, compared with the low and middle SES tertiles. None of the statistical interactions between school year and body fatness was signi®cant, suggesting that the relationship is consistent from childhood to adolescence. CONCLUSION: On the basis of these results, we suggest that health promotion programs aimed at weight management among Australian girls of lower SES are not warranted. We recommend that health promotion programs emphasize regular physical activity, a healthy diet and acceptance of the normal range of body shapes.

Effective strategies to increase energy expenditure and reduce energy intake are being sought by countless agencies around the world. One key strategy will be to enhance health literacy across the population so that everyone will be able to easily understand the energy density of the available foods and drinks. Many countries require that food and drink labels include information on the composition of the food in terms of nutrients, fats, sugars (or overall energy density) and other constituents. However, many people find this information difficult to interpret. 1 Furthermore, take-away food is usually not accompanied by any information about its constituents or energy density.Presenting information on the energy density of foods and drinks, which is quickly and easily understood by most people regardless of their educational background, would make a strong contribution to population health literacy. An effective approach would be to represent the energy density of the food or drink in terms of the amount of activity required to expend the energy contained in a typical serve. For example, the label may state 'Walk 30', indicating that 30 min of walking are typically required to expend the energy consumed in one serve of the food or drink. The consumer will then have an immediate understanding of the behavioural implications of consuming a particular food or drink compared with the alternatives. This behavioural labelling would not replace, but would be in addition to, current nutritional information.Behavioural labelling could be easily applied to labels on packaged foods, cans and bottles and to signs or menus in take-away food restaurants at very low cost. Considering that the energy content of most foods and drinks is already known, converting this information to an equivalent amount of walking would not be difficult. Foods and drinks targeted at children or adolescents could carry information on the amount of time required at one or two of their most popular sports (e.g., 'Football 40') or active play. In the context of the health problems and health care costs accumulating from the obesity epidemic, behavioural labelling would be a high-return investment.

Summary The following enzyme activities were measured in cell lysates and supernatants from mouse peritoneal macrophages incubated with products of cultured tumour and other cells: acid phosphatase, β‐D‐glucuronidase, N‐acetyl‐D‐glucosaminidase, muramidase (lysozyme), lactic dehydrogenase (supernatant only) and plasminogen activator (supernatant only). There were no noteworthy changes in enzyme activities. Hydrogen peroxide production by appropriately stimulated mouse and/or guinea‐pig peritoneal exudate macrophages was variably inhibited by supernatants from some tumour cells and some normal cells. Changes in these biochemical activities of macrophages do not appear to be closely related to the anti‐inflammatory activity of tumour cell products.