In 134 males and 242 females, aged 20-70 years, most of them randomly selected from population studies, the body composition was estimated from the measurements of body height (BH), body weight (BW), total body potassium (TBK) and total body water (TBW). TBK was measured with isotope dilution technique using 42K or determined as 40K in a whole body counter. TBW was determined with an isotope dilution technique using tritiated water, assayed in urine or plasma. From these data, body cell mass (BCM), intra- and extra-cellular water (ICW and ECW, resp.) and body fat (BF) were calculated for each individual. Significant correlations were found between age versus TBK, ECW, BF and ECW/ICW; between BW versus TBK, TBW, ECW, BF and ECW/ICW; (females only) and between BH versus TBK, TBW, ECW (females only) and ECW/ICW. For the prediction of TBK, TBW and BF, multiple regression equations based on BW, BH and age are given. These equations are also presented diagrammatically. The problems with the methods used are considered as well as the applicability of the formulas for the calculation of BCM etc. The predictive value of the results when both TBW and TBK are used for the calculation of body composition data is discussed and compared with similar results, based on TBW or TBK only. It is concluded, that the most reliable method for calculation of BF is to estimate both TBW and TBK.

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A population study of women in Gothenburg, Sweden, is presented. The women were representative of the total female population in Gothenburg in the age strata 38, 46, 50, 54 and 60 years. Altogether 1 462 women participated in the examination, the participation rate being 90.1%. Social data of participants and non‐participants are given. The performance of the examination is described and research projects are outlined. It is concluded that the selection of a strictly representative sample, together with careful uniformity of performance and high participation rate, will make it possible to draw valid conclusions about the total population of middle‐aged women in Gothenburg.

ABS TRA CT A new radioisotope method to measure iron absorption from the whole diet was used in this study. The method is based on the concept that food iron is absorbed from two pools, the heme iron pool and the nonheme iron pool, which can be especially labeled with two radioiron isotopes given as hemoglobin and as an iron salt. The purpose of this study was to test the accuracy of this two-pool extrinsic tag method.The meals served were composed as an average of 6 wk consumption in the present material of 32 young enlisted men. The mean and total heme and nonheme iron absorption in all the 32 young men was 1.01±0.11. This figure agrees well with the mean daily losses expected for this group of subjects (1.0 mg). The conclusion can therefore be made that there are no major systematic errors of the present method to measure the total iron absorption from a mixed diet.In one series a comparison was made of the absorption of heme and nonheme iron from the meals. A significant correlation between the absorption of the two kinds of iron was found. However, a much greater fraction of the heme iron was absorbed (37%) than of the nonheme iron (5%).The absorption both from breakfast and lunch was in two series found to give a good prediction of the total daily nonheme iron absorption. One series was designed to compare the effect of two levels of iron fortification. There was a significant increase in iron absorption when the level of iron fortification of the meals was increased.

The applicability of body composition as estimated by the bioimpedance method to predict energy expenditure (EE) was studied. Ten healthy subjects underwent measurement of body composition and 24-h energy expenditure (24-h EE) twice in a respiration chamber on a fixed program. The 24-h EE and its components, sleeping EE (SEE), basal EE (BEE), and daytime EE, for an individual were very reproducible (coefficient of variation 2.3%, 1.4%, 5.0%, & 3.1%, respectively). The variability of 24-h EE among subjects was 11.4% but only 4.1% when adjusted for differences in lean body mass (LBM). LBM was the best determinant of 24-h EE, BEE, and SEE and accounted for 91-93% of the interindividual variance of EE. The prediction equations were 24EE (kcal/d) = 390 + 33.3 LBM (r2 = 0.93, P = 0.000001), SEE (kcal/h) = 9.8 + 1.1 LBM (r2 = 0.92, P = 0.000001), and BEE (kcal/h) = -3.1 + 1.35 LBM (r2 = 0.91, P = 0.000002). In conclusion, 24EE, BEE, and SEE can be predicted with a high degree of precision from LBM as estimated by bioimpedance in normal-weight subjects.

1. An experimental model for the determination of dietary fibre according to the definition of Trowell et al. (1976) is described. Food was subjected to in vivo digestion in ileostomy patients, and the ileostomy contents were collected quantitatively, the polysaccharide components of which were analysed by gas–liquid chromatography and the Klason lignin by gravimetric determination. The model was used for the determination of dietary fibre in AACC (American Association of Cereal Chemists), wheat bran and for studies on the extent of hydrolysis of wheat-bran fibre in the stomach and small intestine. The effect of wheat bran on ileostomy losses of nitrogen, starch and electrolytes was also investigated.2. Nine patients with established ileostomies were studied during two periods while on a constant low-fibre diet. In the second period 16 g AACC wheat bran/d was added to the diet. The ileostomy contents and duplicate portions of the diet were subjected to determinations of wet weight, dry weight, water content, fibre components, starch, N, sodium and potassium.3. The wet weight of ileostomy contents increased by 94 g/24 h and dry weight by 10 g/24 h after consumption of bran. The dietary fibre of AACC bran, determined as the increase in polysaccharides and lignin of ileostomy contents after consumption of bran, was 280 g/kg fresh weight (310 g/kg dry matter). Direct analysis of polysaccharides and lignin in bran gave a value of 306 g/kg fresh weight. Of the added bran hemicellulose and cellulose 80–100% and 75–100% respectively were recovered in ileostomy contents. There was no significant difference between the two periods in amount of N, starch and K found in the ileostomy contents. The Na excretion increased during the ‘bran’ period and correlated well with the wet weight of ileostomy contents.4. In conclusion, it seems probable that determination of dietary fibre by in vivo digestion in ileostomy patients comes very close to the theoretical definition of dietary fibre, as the influence of bacteria in the ileum seems small. Bacterial growth should be avoided by using a technique involving the change of ileostomy bags every 2 h and immediate deep-freezing of the ileostomy contents. True dietary fibre can be determined by direct analysis of polysaccharides and lignin in the food, at least in bran. Very little digestion of hemicellulose and cellulose from bran occurs in the stomach and small bowel. The 10–20% loss in some patients may be due to digestion by the gastric juice or to bacterial fermentation in the ileum, or both. The extra amount of faecal N after consumption of bran, reported by others, is probably produced in the large bowel.

Objective: A number of long-term population-based studies have tried to study fruit and vegetable consumption in relation to cardiovascular disease, cancer and total mortality. Few of these studies are based on randomly selected population samples. The aim of the study was to investigate the long-term effect of fruit and vegetable consumption on mortality, cardiovascular disease, cardiovascular death, cancer morbidity and cancer death among middle-aged and elderly men. Design: Prospective cohort study. Setting: General community. The Study of Men Born in 1913. Subjects: 792 men at age 54 who participated in a screening examination in 1967. Main outcome measures: A food frequency questionnaire was used to obtain information of the dietary habits in 730 of the men (92%). All men were followed up with repeated examinations until the age of 80. Results: Cardiovascular as well as total mortality was signi®cantly lower among men with high fruit consumption in univariate analysis. There was no correlation between fruit or vegetable consumption in relation to cancer incidence, cancer death and cardiovascular disease. In multivariate survival analysis where smoking, cholesterol and hypertension were taken into account, there was a signi®cantly lower mortality among men with a high fruit consumption during 16 y follow up until the age of 70 (P 0.042), but this ®nding was no longer statistically signi®cant during 26 y follow-up at the age of 80 (P 0.051). Conclusions. Daily fruit consumption seems to have positive effect on long-term survival independently of other traditional cardiovascular risk factors like smoking, hypertension and cholesterol. Sponsorship: This study was supported by grants from the Swedish Medical Research Council (K98-274-06276-17) King Gustav V and Queen Victoria's Foundation, and the Go Èteborg University.

Anthropometric data and body composition, estimated from total body potassium and total body water determinations, were studied in 1968 to 1968 and 1974 to 1975 in a population sample of middle-aged women. Altogether 1302 women participated in the anthropometric studies and 79 women in the body composition studies on both occasions. Body height decreased with age both secularly and biologically. The reduction of body height was greater at higher ages. Body weight increased with age, the change being partly a cohort effect and partly an effect of age. Evidence of a reduced muscle mass in the arms with age was found. Body cell mass increased with age in some age strata. There was an increase in subcutaneous fat with age, both in the arms and in the trunk. Body fat did not change significantly with age in the age strata studied. A change in body weight was accompanied by a smiliar change in both body fat and body cell mass.