Assessment of Bias in National Growth-monitoring Data: A Case Study in Zimbabwe

This study assesses the extent to which children under five years of age attending a growth-monitoring program are representative of the population as a whole. Bias in the prevalence of underweight estimated through growth-monitoring is assessed by comparing data from the program with prevalence estimates from the community-based Demographic and Health Surveys of 1988 and 1994. Geographic patterns of attendance at growth-monitoring are also examined through a comparison with census data, and trends in growth-monitoring data are also assessed. Provincial and national estimates of the prevalence of underweight from the two sources were not significantly different in 1988, but significant differences in prevalence estimates were identified in 1994. This suggests that growth-monitoring attendees were less representative of the general population in 1994 than at the start of the study period. The methodology used is transferable elsewhere, since the same data sets exist for many other African countries.

The high-fat Greek diet: a recipe for all?

OBJECTIVE

To examine critically the published results of dietary surveys on the fat content of the Greek diet, and to assess its evolution and its relationship to the health of the Greeks. To consider the implications of these findings for current views on the nature and health implications of the traditional Mediterranean diet and how best to define it for use in modern policy making.

DESIGN

A systematic review of the literature on food consumption in Greece.

SETTING

Greece.

RESULTS

The first fully published data on the fat content of the Greek diet-the Seven Countries Survey-relates only to a small number of adult males in Crete and Corfu; the legitimacy of extrapolating these results to the rest of Greece is questioned. Earlier studies and chemical validation of intakes point to a lower fat content of the traditional diet than that inferred for Crete. Nearly all later surveys relate only to urban groups in Athens (mostly case-control hospital-based samples) and a variety of non-representative Cretan groups. Only two studies are larger and more representative, but one uses FAO food balance-sheets to reflect the national diet, and the other surveyed school-age children in three out of the 52 Greek counties. Unfortunately recent dietary studies have proved unreliable, given the continuing lack of national food composition tables with survey methods which proved inaccurate for dietary fat content. A progressive upward trend in total and saturated fat intake appears to have occurred with all health indicators in relation to fat indicating remarkable increases in adult and childhood obesity with attendant progressive deterioration in cardiovascular mortality and its risk factors, ie hypertension and diabetes. These data emphasise the need to alter current nutritional advice in Greece, particularly when it focuses on the promotion of olive oil and a high-fat diet.

CONCLUSIONS

The findings reaffirm low-moderate fat policies for optimum health, within which olive oil can be an important component of the diet.

Seasonal aspects of weight-for-age in young children in Zimbabwe

OBJECTIVE

To identify the season with the highest prevalence of underweight among young children and to examine geographical variation in seasonality of underweight.

DESIGN

This analysis is based on monthly data from a clinic-based growth monitoring programme that forms part of the National Health Information System. A regression-based technique is used to identify seasonal patterns in both underweight prevalence and attendance nationally and in 60 different districts.

SETTING

The analysis covers the period 1988-1995 and is based in Zimbabwe.

SUBJECTS

The analysis is based on weight-for-age measurements of Zimbabwean children less than 5 years old, who attended health centres as part of a growth monitoring programme.

RESULTS

Nationally, a small but significant increase in levels of underweight takes place during January-March. Participation in growth monitoring also varies seasonally and could account for the increase observed. No evidence of seasonal variation in underweight prevalence is found in the majority of districts studied, although 11 of the districts showed a similar pattern to the national data set. This peak in the incidence of poor nutritional status also coincides with the period of food scarcity before harvest, which is also associated with higher prevalence of diarrhoea and malaria. No differences in seasonality of under-nutrition were found between districts with predominantly subsistence agriculture and those with more commercial forms of agriculture.

CONCLUSIONS

Seasonal variation in child weight-for-age exists in some parts of Zimbabwe, but its effects on cross-sectional prevalence studies are likely to be small. There are no readily discernible differences between areas that show evidence of seasonality in levels of underweight and those that do not.

High-performance liquid chromatography with coulometric electrode array detector for the determination of quercetin levels in cells of the immune system

There is mounting evidence emphasizing the importance of intracellular antioxidant levels for maintenance of the immune function. The flavonoid quercetin, a natural antioxidant, has been shown to modulate enzymes involved in the regulation of the inflammatory response. However, up to now, there have been no studies describing quercetin levels in cells of the immune system. A gradient reversed-phase HPLC technique to identify and quantify intracellular levels of quercetin and its application in mice splenocytes are described. Mobile phases were a 0.01 M sodium phosphate monobasic solution adjusted to pH 2.8 with 85% orthophosphoric acid (buffer, Solvent A) and methanol (Solvent B) with a flow rate of 1 ml/min. An eight-channel coulometric electrode array detector was used. In vitro supplementation with increasing concentration of quercetin (25, 50, and 100 microM) raises intracellular quercetin levels in a dose-dependent manner. The method has the required features of specificity and sensitivity for monitoring quercetin uptake in cells of the immune system.

Basal metabolic rate in anorexia nervosa: relation to body composition and leptin concentrations

BACKGROUND

Leptin is thought to represent a peripheral signal involved in the regulation of energy balance. Its action has been studied in animals and obese subjects. Little is known about leptin's role during negative energy balance.

OBJECTIVE

The objective was to evaluate the relation between energy turnover, body composition, and plasma leptin concentrations in anorexia nervosa (AN).

DESIGN

Sixteen weight-stable women with AN were compared with 22 control subjects and 14 rehabilitated AN patients (R-AN). Basal metabolic rate (BMR) was measured by indirect calorimetry; fat-free mass (FFM) and fat mass (FM) were calculated according to a 4-compartment model. Plasma leptin was determined by radioimmunoassay.

RESULTS

The BMR of AN patients (2.73 +/- 0.37 kJ/min) was significantly lower than that of control subjects (3.45 +/- 0.34 kJ/min) (P < 0.001), even after adjustment for FFM (2.92 +/- 0.33 kJ/min in AN patients and 3.30 +/- 0.26 kJ/min in control subjects; P < 0.004). Plasma leptin concentrations in AN patients were 76% lower than in control subjects, even after body fat was controlled for. In R-AN patients, BMR was not significantly different from that of control subjects and leptin concentrations were generally close to normal. Plasma leptin concentrations correlated significantly with FM (r(2) = 0.53, P < 0.0000) and BMR, even after adjustment for FFM (r(2) = 0.21, P < 0.0003).

CONCLUSIONS

BMR and plasma leptin concentrations are depressed in patients with AN; this is not explained by body-composition changes. The relation between leptin and BMR suggests that leptin plays a role in the energy sparing response to exposure to chronic energy deficiency. The return of BMR to normal and the significant increase in leptin concentrations in R-AN patients suggests a full reversibility of this adaptation mechanism.

The potential use of maternal size in priority setting when combating childhood malnutrition

OBJECTIVE

To devise a strategy for assessing the nutritional status of a household and specifying the major needs in combating childhood wasting, distinguishing between inadequate food availability, poor parental care and/or the need for improved public health measures.

DESIGN

An evaluation of the relationship between children's wasting, stunting, or underweight and mothers' or adult women's body mass indexes (BMIs) in the same household. A household was designated as 'malnourished' on the basis of a single child's weight/height of < -2.0 s.d. or at risk of being malnourished if the Z-score was below--1.5. Adult women's BMI was taken to signify adequate household food availability. Sibling concordance of anthropometric measures was investigated.

RESULTS

A wide variety of prevalence of severe (BMI < 16.0), moderate (BMI 16.0-16.9) and marginal (17.0-18.4) malnutrition existed in the various study areas. The worst condition was recorded in India, while 18% of the women in Zimbabwe were classified as obese. Similarly wide variation in the prevalence of child wasting and stunting was observed, with the Indian children again faring worst and those in Zimbabwe the best. The within-household analysis of concordance gave higher concordance for height than for weight between siblings. Mothers' BMI was highly correlated with the BMI of all other adult women in the same household and the BMI of all the women was found to be as useful as that of the mother for relating to children's anthropometry. Households with mothers of normal body weight but wasted children were designated as in need of public health measures and improved parental care rather than of enhanced food security. The distribution of households on this combined basis of maternal BMI and child nutritional status highlighted very diverse situations in the various study areas, with higher proportions of combined maternal and child malnutrition in India and in some areas of Ethiopia, while in Zimbabwe only 1-2% presented this condition. On this basis, the principal problem in India was food security; in Zimbabwe household security was rarely apparent, so public health measures and maternal care were designated as problems. In three Ethiopian communities there was a mixture of needs.

CONCLUSIONS

A relatively simple household-based approach is proposed to discriminate the most pressing needs in combating childhood malnutrition, and a policy-making tool is suggested for setting priorities in community action.

Body composition changes in anorexia nervosa

OBJECTIVE

To assess the body composition changes in anorexia nervosa and after medium term recovery.

DESIGN

A descriptive study.

SETTING

Rome, Italy.

SUBJECTS

Twenty women affected by anorexia nervosa (AN) with a BMI [weight (kg)/height (m2)] below 17 kg/m2 and weight-stable for at least three months, were compared with 10 well nourished control women (CO) and nine rehabilitated subjects (R-AN), who had a BMI above 18.5 kg/m2 stable for at least the last six months.

INTERVENTIONS

Body fat was assessed by underwater weighing, muscle mass by urinary creatinine, total body water (TBW) by impedance parameters (50 kHz and 800 microA), skeletal mass by anthropometry and radius bone mineral density by dual photon absorptiometry in ultra-distal (UD-BMD) and medio-distal (MD-BMD) sites.

RESULTS

The AN group, as compared to the control group, had a significantly lower weight, body mass index (BMI kg/m2) and percent body fat (P < 0.0000). Creatinine urinary excretion was lowest in absolute term and when expressed as creatinine height index or per kg fat free mass (FFM) (P < 0.0000); muscle mass per kg body weight was 13% lower (P < 0.01). Ultra distal bone mineral density (UD-BMD) was 6% lower (not significant). TBW as percent of body weight was significant higher (P < 0.001): however TBW/FFM % was not statistically different with large inter-individual variability. An altered distribution of extra and intra-cellular water was suggested by the phase angle (AN: 4.4+/-0.8 degrees; CO: 6.1+/-0.4 degrees; (P < 0.0000). In rehabilitated anorexic patients (R-AN) the fat mass represented 53% of the weight gain. Their creatinine excretion remained still below the mean value of the controls (P < 0.001). The impedance parameters were not significantly different between the R-AN and the CO groups, however, the phase angle of the R-AN (5.0+/-0.7 degrees) remained lower than in the CO group, indicating that the water distribution was still altered.

CONCLUSIONS

This study shows that AN is a condition of reduced body fat as well as of muscle mass, with a slightly reduced bone mass. In the course of rehabilitation, most of the weight regained is represented by fat, while the muscle mass appears to lag behind, at least in the medium term.

Alcohol-free red wine enhances plasma antioxidant capacity in humans

Moderate wine consumption is reputed to exert a protective effect against coronary heart disease (CHD). The nature of the protective compounds is unclear and the mechanisms are incompletely understood. We studied whether the nonalcoholic component of wine increases plasma antioxidant capacity measured as total radical-trapping antioxidant parameter (TRAP), and whether such an effect is associated with the presence of phenolic compounds in plasma. The TRAP and plasma levels of phenolic compounds were measured in 10 healthy subjects after the ingestion of 113 mL of tap water (control) and alcohol-free red and white wine at 1-wk intervals. Both alcohol-free wines possessed an in vitro dose-dependent peroxyl-radical activity, but red wine, with a polyphenol concentration of 363 +/- 48.0 mg/L quercetin equivalent (QE), was 20 times more active (40.0 +/- 0.1 mmol/L) than white wine (1.9 +/- 0.1 mmol/L), which has a polyphenol concentration of 31 +/- 1 mg QE/L. The ingestion of alcohol-free red wine caused significant increases in plasma TRAP values and polyphenol concentrations 50 min after ingestion. Alcohol-free white wine and water had no effects on either of the plasma values. The parallel and prompt increase of antioxidant status and of circulating levels of polyphenols in fasting subjects after bolus ingestion of a moderate amount of alcohol-free red wine suggests that polyphenols are absorbed in the upper gastrointestinal tract and might be directly involved in the in vivo antioxidant defenses.

The basal metabolic rate and energy cost of standardised walking of short and tall men

OBJECTIVES

To assess the influence of stature on the basal metabolic rate (BMR) and on the energy cost of standardised walking. A second objective was assess the accuracy of the FAO/UNU/WHO (1985) equations to predict BMR.

DESIGN/SUBJECTS

Forty-six young men were selected on the basis of their stature and assigned to the group of short, S (n = 25, mean stature = 1.65 +/- 0.03 m) or of tall, T (n = 21, mean stature = 1.87 +/- 0.04 m).

SETTING

Rome, Italy.

INTERVENTIONS

Body composition was assessed by underwater weighing. BMR and energy cost walking at 5 km/h was measured by the Douglas bag.

RESULTS

Body fat % was similar in the two groups (15.2 +/- 4.3 for S; 17.4 +/- 5.3 for T; ns). The BMR of T was 20% higher than that of S, but 12% and 10% lower when standardised respectively for body weight (BW) and fat free mass (FFM). However these differences were removed when BMR was covaried for BW or FFM, or normalised by BW0.62 or FFM0.64. Measured BMR was 7% for T and 6% for S lower than that predicted by the FAO/WHO/UNU (1985) equation; the inclusion of stature did not reduce the overestimation. The energy cost of walking was 27% higher in T than in S, but 9% and 5% lower when standardised respectively for BW and FFM. The differences disappeared when expressing the energy cost of walking as net cost per kg FFM.

CONCLUSIONS

Tall people have lower BMR per unit of BW or FFM than short people, and it is necessary to control for the diverse body mass by the appropriate method. However, qualitative differences in the composition of FFM are plausible, due to the diverse proportion of metabolically active internal organs in people of different height, which might be reflected in the higher BMR/kg FFM of the shorter subjects. The sex- and age-specific FAO/WHO/UNU (1985) equation significantly overestimates the BMR of both short and tall people, but there is no simple explanation of this observation. The energy cost of walking is not affected by stature when expressed as net cost per kg FFM.

Validation of expedient methods for measuring body composition in Indian adults

The body composition of 99 men and 89 women from south India was estimated using hydrodensitometry, bioelectrical impedance and skinfold thickness. Comparisons of the hydrodensitometry (reference method) and skinfold methods showed that there were no significant differences between the methods, for estimates of fat free mass (FFM) and per cent fat. The mean difference between the estimates FFM (bias), from skinfold measurement and hydrodensitometry was small for both groups (+0.16 +/- 1.09 kg in men and +0.67 +/- 0.9 kg in women). The same trend was observed in per cent fat estimates (-0.37 +/- 2.04 in men and -1.49 +/- 2.28 in women), showing that the skinfold method can be used as an accurate and expedient method to determine body composition. The bioelectrical impedance method obtained a significantly lower FFM and higher body fat than the reference (hydrodensitometry) method. This could have been due to the use of an inappropriate equation derived from Western population studies. Hence, a new predictive equation, for the measurement of FFM by the bioelectrical impedance method was derived for this population, using the variables of height2/impedance and FFM measured by underwater weighing. The new equation for the bioelectrical impedance method then gave values of body composition which compared well (0.26 +/- 2.32 kg) in men and (0.36 +/- 2.49 kg) in women with the hydrodensitometry method.

Basal metabolism of weight-stable chronically undernourished men and women: lack of metabolic adaptation and ethnic differences

The purpose of this study was to investigate whether weight-stable chronically energy-deficient subjects exhibit evidence of metabolic adaptation and to establish whether international predictive equations overestimate the basal metabolic rate (BMR) of tropical populations. BMR, body weight, height, and fat-free mass (FFM) by underwater weighing were measured in healthy, physically active urban dwellers of low socioeconomic status (178 men and women aged 22-38 y) in Bangalore, Southern India. Subjects were selected on the basis of body mass index (BMI; in kg/m2) and classified in three groups: severely undernourished (BMI < 17.0; n = 30 men, n = 25 women), marginally undernourished (BMI = 17.0-18.5; n = 31 men, n = 30 women), and well nourished (BMI > 18.5; n = 27 men, n = 35 women). The BMR of the well-nourished group, expressed in absolute terms (6.20 and 5.18 MJ/d for men and women, respectively), was significantly higher (P < 0.000) than that of the severely undernourished group (5.72 and 4.64 MJ/d for men and women, respectively). Normalizing BMR for either body weight or FFM by analysis of covariance abolished all differences. The mean BMR of the low-BMI study group was substantially higher (11-14%) than reported previously for undernourished Indian adults. The BMR of both men and women, regardless of their nutritional status, was accurately estimated by age- and sex-specific FAO/WHO/UNU equations. These findings suggest the absence of an enhanced metabolic response in weight-stable chronically undernourished adults. This is in contrast with earlier reports, and supports more recent views. The study also provides evidence of the absence of ethnic-specific energy turnover in Indians.

Plasma (carotenoids, retinol, alpha-tocopherol) and tissue (carotenoids) levels after supplementation with beta-carotene in subjects with precancerous and cancerous lesions of sigmoid colon

OBJECTIVES

(1) To compare tissue and plasma carotenoids status of healthy subjects and subjects with pre-cancer and cancer lesions; (2) to evaluate the effect of beta-carotene supplementation on the concentrations of other carotenoids in tissue (luteine + zeaxanthin, cryptoxanthin, lycopene, alpha-carotene) and in plasma and also retinol and alpha-tocopherol levels.

DESIGN

Eighteen subjects were divided into three groups on the basis of colonoscopy and histological analytical findings: four healthy subjects (control group A); seven subjects affected by adenomatous polyps (group B with pre-cancer lesions); seven subjects suffering from colonic cancer (group C). Blood and colonic biopsy samples were taken (of colon and rectal mucosa) before and after beta-carotene supplementation in all subjects. Groups A and B received a daily dose of beta-carotene (30 mg/die) for 43 d. Group C's supplementation was terminated at the time which was performed, usually within 15 d. The tissue and plasma concentration of carotenoids, retinol and alpha-tocopherol were determined by high-performance liquid chromatography.

RESULTS

The tissue concentrations of each carotenoid were similar in all the intestinal sites examined as regards groups A and B, although there was a high degree of intra individual variability within each group. Only beta-carotene made significant increases (P < 0.001) after supplementation. The subjects with cancer show tissue levels for each carotenoid lower than those of healthy subjects or subjects with polypous. The plasma levels of alpha-tocopherol did not change after supplementation while significant increases were noted of retinol, alpha-carotene (P < 0.01) and of beta-carotene (P < 0.001).

CONCLUSIONS

The patients with colonic cancer seemed to undergo a significant reduction in their antioxidant reserves with respect to the normal subjects and or polyps. We can confirm that oral B-carotene supplementation induces also an increase in plasma alpha-carotene in all groups.

A new look at dietary carbohydrate: chemistry, physiology and health. Paris Carbohydrate Group

The current view of dietary carbohydrates as simply providing us with energy is outdated. Because of their varied chemistry and physical form the rate and extent to which the different types are digested in and absorbed from the small intestine varies. This in turn leads to affects on satiety, blood glucose and insulin, protein glycosylation, lipids and bile acids. Some carbohydrates reach the colon where they are fermented and affect many aspects of large bowel function, colonocyte and hepatic metabolism. A new framework for classifying and measuring food carbohydrates is needed to allow a greater understanding of the role of individual species in health and to inform the public of their importance. A classification based primarily on molecular size (degree of polymerisation) into sugars, oligosaccharides and polysaccharides, is suggested, with sub-groups identified by the nature of the monosaccharides. Greater knowledge of the chemical and physical properties of carbohydrates allow a more precise relation with physiology and health to be drawn. The Carbohydrate Group met in Paris in December 1995 at the invitation of Gerard Pascal, Director of CNERNA. Financial support for the meeting was provided by CNERNA.

Body composition by a three compartment model in adult Indian male and female subjects

The body composition of 10 adult Indian male and female subjects was investigated by a three compartment model, using measurements of Total Body Water (TBW) by deuterium dilution, and of body density by hydrodensitometry. The three compartment model yielded significantly different (P < 0.005) estimates of percent body fat of 15.9+/-3.8 and 19.7+/-4.2% and of the Fat Free Mass (FFM) of 41+/-3.3 kg and 33.9+/-4.1 kg in the male and female subjects respectively. The hydration of the FFM was 0.704+/-0.032 in the males and 0.719+/-0.024 in the females; this difference was not signifcant between groups. The density of the FFM, measured from estimates of percent body fat by the 3 compartment approach and of body density by hydrodensitometry, was 1.107+/-0.014 in the males and 1.101+/-0.001 in the females with no significant differences between the groups. This study demonstrates differences in body composition between BMI matched healthy adult male and female subjects. Although there are significant differences for % Fat and FFM between the sexes, there are no significant differences in the hydration fraction and the density of the FFM.

Application of a new high-performance liquid chromatographic method for measuring selected polyphenols in human plasma

We developed a method to measure plasma levels of selected polyphenols before and after ingestion of green tea. Blood samples were obtained from four healthy women before and 30 and 50 min after the ingestion of 300 ml of green tea infusion. A 1-ml volume of plasma was hydrolysed with 0.5 M HCl-methanol (1:1, v/v) for 30 min at room temperature, extracted with ethyl acetate and separated by reversed-phase chromatography. Polyphenols were identified on the basis of their retention times and by spectrum analysis. Green tea caffeine has the same retention times as caffeic acid. Consumption of green tea produces a notable increase in the plasma levels of caffeine plus caffeic acid and the appearance of measurable levels of epigallocatechingallate. In conclusion, the method was found to have the requisite features of specificity and sensitivity for monitoring plasma levels of selected tea polyphenols.

Total body water measurements by deuterium dilution in adult Indian males and females

Total Body Water (TBW) was measured in a group of 20 healthy adult Indian men and 10 women by the deuterated water dilution technique and their body composition was determined by applying a hydration factor of 0.7194 for fat free mass (FFM). The TBW in the male subjects whose mean body weight was 49.8 +/- 6.7 kg, was 60.6 +/- 3.2% of body weight (range 55.8%-65.4%), from which a FFM of 41.9 +/- 6.1 kg (range 31.8 kg-51.3 kg) was obtained. Total body water in the group of 10 female subjects whose mean body weight was 42.7 +/- 4.9 kg, was 57.0 +/- 4.5% of body weight (range 52.5%-64.2%) from which a FFM of 34.0 +/- 5.1 kg (range 28.4 kg-39.4 kg) was obtained.

Adult malnutrition: simple assessment techniques for use in emergencies

The recent recognition of the problem of adult malnutrition requires methods for specifying the severity of undernutrition. The measurement of mid upper arm circumference (MUAC) can now be used as a screening method for underweight (normally assessed from the BMI) or as an additional criterion with the BMI to identify the preferential loss of peripheral tissue stores of fat and protein. By analysing and extrapolating anthropometric data from nine detailed adult surveys from Asia, Africa and the Pacific a series of MUAC cut-off points have now been identified to allow the screening of individual adults under extreme conditions, e.g. during famine. Grade 4 malnutrition is now specified for those with a MUAC < 200 mm for men and < 190 mm for women since these MUAC values correspond to the loss of fat stores at BMI of < 13. Food supplementation is clearly needed in these individuals. Extreme wasting (grade 5 malnutrition) corresponds to MUAC values of < 170 and < 160 mm for men and women respectively. These adults have extremely low BMI, i.e. about 10, have lost most, if not all, of their protein stores and are at a high risk of imminent death. These individuals will need immediate special feeding regimens to ensure their survival. The sex-specific MUAC values corresponding to BMI of 16, 13 and 10 can now therefore be used for rapid screening and the choice of remedial action.

In vivo antioxidant effect of green and black tea in man

OBJECTIVE

Evaluation of the vitro antioxidant activity of green and black tea, their in vivo effect on plasma antioxidant potential in man and the effect of milk addition.

DESIGN

The antioxidant activity of the tea, with and without milk, was tested in vitro by measuring the length of the peroxyl radical induced lag-phase. The in vivo activity was tested on two groups of five healthy adults. Each group ingested 300 ml of either black or green tea, after overnight fast. The experiment was repeated on a separate day, adding 100 ml whole milk to the tea (ratio 1:4 ). Five subjects acted as controls. The human plasma antioxidant capacity (TRAP) was measured before and 30, 50 and 80 min from the ingestion of tea.

RESULTS

Both teas inhibited the in vitro peroxidation in a dose-dependent manner. Green tea was sixfold more potent than black tea. The addition of milk to either tea did not appreciably modify their in vitro antioxidant potential. In vivo, the ingestion of tea produced a significant increase of TRAP (P <0.05), similar in both teas, which peaked at 30-50 min. When tea was consumed with milk, their in vivo activity was totally inhibited.

CONCLUSIONS

The paper shows that tea possesses a strong antioxidant activity in vitro which is believed to be exerted by its polyphenols moiety. It also provides compelling evidence that tea has also a potent in vivo activity in man. The promptness of the in vivo response suggests that the absorption of the bioactive components of tea takes place in the upper part of the gastrointestinal system. The inhibition of this effect by milk is thought to be due to the complexation of tea polyphenols by milk proteins. These findings might help to clarify the putative role of dietary poly- phenols in modulating oxidative stress in vivo.

Obesity and physical activity

This paper discusses the epidemiological evidence linking obesity to physical activity. The underlying plausible hypothesis is that the feedback from energy expenditure to appetite may be weak at low levels of physical activity and that sedentary lifestyles therefore favour positive energy balance and weight gain. Obesity is widespread in developed countries and appears to have a marked secular trend. An analysis of time-budget surveys reveals that the time required for earning a living and domestic work has declined appreciably over recent decades. This negative secular trend is associated with a substantial decline in the energy spent on these activities. The contraction of work time has resulted in a converse expansion of free time, but the bulk of this is spent on passive leisure. Thus, at least for western societies, the overall energy expenditure has fallen for some decades and lifestyles have become increasingly more sedentary. The review of a large data set on energy expenditure under free-living conditions indicates that, despite their phenomenally diverse rates of obesity, there is no systematic difference between developed and developing societies. Multivariate regression analysis of body mass index on physical activity level (PAL) reveals a weak but statistically significant inverse relationship in men but not in women, and establishes that the risk of obesity increases sharply at a PAL of less than 1.80. In conclusion, a critical level of PAL has been identified, below which the chances of being overweight become substantial. The use of time is modelled contextually with its energy cost to show the extent to which energy expenditure may be modified. This has relevance from a policy standpoint, allowing a more focused approach for obesity prevention.

Thyroid homeostasis and retinol circulating complex relationships in a severe iodine-deficient area of Senegal

In adult subjects living in a severely iodine-deficient area (median urinary iodine 10 microgram/L), we evaluated the biochemical parameters of protein malnutrition in relation to thyroid homeostasis. Serum transthyretine (TTR), retinol binding protein (RBP) and retinol, all components of the retinol circulating complex (RCC), as well as ceruloplasmin levels, were determined in 63 subjects (44 F/19 M). These comprised 21 controls, 31 who were euthyroid with goiter WHO stage 2 or 3 and 11 who met the criteria of hypothyroidism (i.e. FT4 < 8 pmol/L and TSH > 4.13 mU/L) with goiter stage no more than 1b. No differences in the values of TTR and RBP were found between males and females, whereas the retinol values were slightly higher in males. The mean retinol binding protein values were lower than the normal range in all three groups but were significantly lower (p < 0.01; < 0.05) in hypothyroid subjects than in the other two groups. All hypothyroid subjects exhibited reduced retinol binding protein levels and 1/3 of them showed a marked decrease. The circulating levels of transthyretine were also lower than the normal range for western countries. 45% of the hypothyroid, 26% of goitrous and 9% of control subjects exhibited a transthyretine lower than 12 mg/dl, but the mean values were not dissimilar. The mean retinol values were within the normal range in all three groups but were lower in hypothyroid as compared to the controls (< 0.01). The resulting retinol/RBP ratio was over 1 in both the whole sample and in the subgroups. Ceruloplasmin levels were in the normal range in all groups. The data indicated that hypothyroid subjects had reduced retinol binding protein and retinol circulating complex network compared to euthyroid subjects.

Mediterranean diet, Italian-style: prototype of a healthy diet

Since Keys' first observations in the 1960s, the Mediterranean diet has been under scrutiny by researchers and public health specialists for its health-promoting qualities. Detailed analyses of food surveys carried out in Italy at that time permitted a definition of an Italian-style Mediterranean diet, characterized by low total fat (< 30% of energy), low saturated fat (< 10% of energy), high complex carbohydrates, and high dietary fiber. The importance of the plant components of this dietary pattern became increasingly recognized as a result of advances in the understanding of the pathophysiology of chronic and degenerative diseases. Thus, the Mediterranean diet was found not only to produce favorable effects on blood lipid profiles, but also to protect against oxidative stress and carcinogenesis. However, possible unwanted effects, such as those on micronutrient bioavailability, also must be taken into account. In recent years, despite an increase in consumption of animal foods, the dietary profile of southern Italy has maintained its basic features, and vital statistics still demonstrate a comparative advantage of eating behaviors in Mediterranean countries.

Mediterranean diet pyramid: a cultural model for healthy eating

We present a food pyramid that reflects Mediterranean dietary traditions, which historically have been associated with good health. This Mediterranean diet pyramid is based on food patterns typical of Crete, much of the rest of Greece, and southern Italy in the early 1960s, where adult life expectancy was among the highest in the world and rates of coronary heart disease, certain cancers, and other diet-related chronic diseases were among the lowest. Work in the field or kitchen resulted in a lifestyle that included regular physical activity and was associated with low rates of obesity. The diet is characterized by abundant plant foods (fruit, vegetables, breads, other forms of cereals, potatoes, beans, nuts, and seeds), fresh fruit as the typical daily dessert, olive oil as the principal source of fat, dairy products (principally cheese and yogurt), and fish and poultry consumed in low to moderate amounts, zero to four eggs consumed weekly, red meat consumed in low amounts, and wine consumed in low to moderate amounts, normally with meals. This diet is low in saturated fat (< or = 7-8% of energy), with total fat ranging from < 25% to > 35% of energy throughout the region. The pyramid describes a dietary pattern that is attractive for its famous palatability as well as for its health benefits.

A fluorescence-based method for measuring total plasma antioxidant capability

The Total Radical-Trapping Antioxidant Parameter (TRAP) of 10 freshly prepared human plasmas was measured by a new fluorometric assay. In this method, the rate of peroxidation induced by 2,2'-diazobis (2-amidinopropane) dihydrochloride (ABAP) was monitored through the loss of fluorescence of the protein R-Phycoerythrin (R-PE). The lag-phase induced by plasma was compared to that induced by 6-hydroxy-2,5,7,8-tetramethylchroman-2- carboxylic acid (Trolox, a water-soluble analogue of vitamin E). Proteins (but not their sulphydryl groups) interfere with the analysis, partially protecting R-PE when all plasma antioxidants are exhausted. A Trolox-induced lag-phase must therefore be measured on each plasma sample. We found that ascorbate (2.5-5.3%), alpha-tocopherol (2.9-8.5%), urate (19.6-61.0), and thiol groups (17.3-42.3%) jointly explain up to 70% of TRAP. Thus, either other compounds present in plasma are likely to exert antioxidant action, or a marked synergistic action between antioxidants should be postulated to exist. This latter hypothesis is supported by the finding that the simultaneous inactivation of ascorbate and thiol groups produces a loss in antioxidant capacity of plasma greater (26%) than the sum of the decreases produced by the separate inactivation of each of the two compounds. The proposed method appears simple, reliable, and allows the rapid handling of a reasonable number of freshly prepared plasma samples. Given the rapid loss of TRAP upon storage, the latter characteristic is crucial in studies on humans, involving a large number of subjects.

Use of body mass index of adults in assessing individual and community nutritional status

Adult malnutrition is much more widespread than is commonly recognized. Described in this article is the use of body mass index (BMI = weight in kg/(height in metres)2) as a measure of adult nutritional status, both of individuals and of communities. Concurrent assessment of the nutritional status of children and adults permits conclusions to be drawn about whether there is generalized undernutrition in a community or whether other factors (e.g., childhood infections or feeding practices) are more important in childhood malnutrition. Included is a tabular presentation that permits rapid assessment of both thinness or underweight (BMI values < 16, 17 and 18.5) and overweight (BMI > 25, 30 and 40). Examples of the use of BMI in both clinical and public health practice are also given.

Accumulation of beta-carotene in normal colorectal mucosa and colonic neoplastic lesions in humans

The quantity of beta-carotene (BC) accumulated in colonic polyps and colonic cancerous tissue in humans in situ was determined relative to the quantity accumulated in normal colon and rectal tissue. Serum concentration of BC, retinol, and alpha-tocopherol and tissue BC concentration were determined by high-performance liquid chromatography in samples obtained before and after oral supplementation with BC (30 mg/day). The serum BC and retinol concentrations significantly increased in response to supplementation in control, polyp, and cancer patients, but there was no change in serum alpha-tocopherol concentration. The BC concentration in tissue (colon, rectum, and tumor) of cancer patients was significantly less than that in tissue samples from control and polyp patients. Relative to baseline values, BC accumulated to a significant extent in tissues from all patients, including polyp and tumor tissue, during supplementation. The results indicate that BC does accumulate in colonic neoplastic tissue in humans and may potentially be utilized to augment cytotoxicity of chemotherapeutics or to prevent malignant transformation of cells.

The value of arm circumference measurements in assessing chronic energy deficiency in Third World adults

OBJECTIVE

To assess the usefulness of mid-upper arm circumference (MUAC) as a substitute for body mass index (BMI: kg/m2) or an additional measure of adult nutritional state.

DESIGN

Variously sampled adults aged 18-60 years from selected regions of five African countries, India, China and Papua New Guinea were measured.

SUBJECTS

2421 men and 3248 women were measured for their heights, weights and MUAC. Of these, 1569 men and 1905 women also had their triceps skinfold thickness measured, thus allowing additional estimates of muscle area circumferences and fat areas in the arm.

RESULTS

MUAC and BMI were highly correlated in each national group; each group's MUAC differed from the overall mean MUAC at any BMI value by < 10%. Women's MUACs were smaller than men's at equivalent BMIs. Increases in MUAC with age were statistically significant but trivial. Muscle and fat measurements showed similar increases with BMI; a larger muscle mass in men explained their greater MUACs but muscle differences alone did not explain national variations in MUAC. The -1 SD MUAC value, taken as an independent measure of peripheral tissue wasting, readily distinguished those with a BMI < 16.0 from those with a BMI > 18.5; intermediate grades of BMI were poorly specified by MUAC values.

CONCLUSION

MUAC values of 23.0 cm in men and 22.0 cm in women are useful cut-off points for simple screening of nutritional state. In combination with BMI it may provide a more refined classification of CED. This new combined classification scheme may be a better means of discriminating the at-risk underweight adults from those who are thin but not at risk.

Body mass index defines the risk of seasonal energy stress in the Third World

A method has been devised to quantify the effect of seasonal environmental stress on nutritional well-being and to estimate the proportion of Third World populations at risk of functional deterioration. An Index of Agro-Climatic Seasonality, IACS--a measure of potential agricultural biomass availability--has been developed from agro-climatic data. IACS was found to be highly correlated with the seasonal weight loss of adults in rural Third World communities. This relationship was then used to predict the existence and severity of seasonal energy stress incurred by the adult population of Third World countries at any given body mass index (BMI). The average weight loss recorded in all seasonality studies was calculated; this value was used to specify, in combination with BMI, a condition of moderate seasonal energy stress. This grade of energy stress involved a loss of about 2% fat-free mass. The risk of greater energy stress, with larger losses of lean tissue, was specified as severe when predicted weight changes exceeded the maximum losses of weight recorded--at any given BMI--in Third World rural communities. The global dimensions of seasonality were then calculated by enumerating the individuals who--by the combined criteria of the BMI and the IACS of the habitat--fell into the categories of moderate and severe seasonality risk. On this basis, 65% of the rural adult population in the Third World run the risk of at least moderate seasonal energy stress, while 45% fall into the severe stress category. Of these 25% qualify as true seasonal 'casualties' because their body weight loss shifts their BMI from the normal range of nutritional status into the category of chronic energy deficiency.

Malnutrition and the immune response. 1. Malnutrition in the community: recent concepts

Anthropometric indicators have long been used to define the nutritional status of children although anthropometric studies of adult nutritional status have been accorded low priority. As a result, the nutritional status of a community is largely based on estimates of childhood undernutrition alone. The prevalence of adult undernutrition is also variably estimated since objective measures of adult undernutrition are not applied. Body mass index may provide an ideal method for filling this gap since this simple anthropometric index well reflects the physiological, social and economic consequences of adult undernutrition in a community. It also enables assessment of the impact of intervention strategies aimed at developmental or public health outcomes in population groups world-wide.

Relationship between fat-free mass and urinary excretion of creatinine and 3-methylhistidine in adult humans

The urinary excretion of endogenous creatinine (CRTN) and 3-methylhistidine (3-MH) has been proposed as a predictor of fat-free mass (FFM) in healthy subjects. In this study, we report the relationship between FFM, estimated by densitometry plus deuterium dilution, and daily urinary excretion of CRTN and 3-MH in a sample of 20 healthy adult subjects of both sexes. 3-MH and CRTN were measured in 2 days of urine collection, which followed 4 days of meat-free diet. Meat-free diet was maintained throughout the period of urine collection. The mean of 2 days of excretion of 3-MH was 237.7 +/- 87.3 (SD) and 138.9 +/- 31.2 mumol/day in men and women, respectively. The mean CRTN excretion was 1.51 +/- 0.22 and 0.98 +/- 0.15 g/day in men and women, respectively. CRTN excretion was found well associated with FFM (R2 = 0.89; P < 0.0001), whereas 3-MH was lightly associated with FFM (R2 = 0.33; P < 0.01). Residuals from the regression of 3-MH vs. FFM were found to be correlated with CRTN excretion and FFM (R2 = 0.57 and 0.67, respectively), suggesting that muscularity and the absolute amount of lean mass are relevant for the error in predicting FFM from 3-MH excretion. Data confirm that urinary CRTN excretion can be an expedient indirect method for evaluating body composition in healthy adult subjects. Data also suggest that the relationship between 3-MH and FFM is complex, limiting the possibility of predicting body composition from the excretion of this metabolite.

Seasonal energy stress in an Ethiopian rural community: an analysis of the impact at the household level

The household integrated response to seasonal fluctuations in food availability and work load was assessed in a longitudinal study in two villages of southern Ethiopia. The household response to energy stress was estimated by pooling weight changes of all members of the family, accounting for the diverse biological and functional meaning of weight losses of different age and sex groups, and levels of nutritional status. On average, seasonal energy stress experienced by the households was modest (3.3%, P < 0.05 by Tukey test). The cumulative weight change of poor households was twice as large as that of rich ones, and evidence was obtained of their further deterioration over the following agricultural year. Household food availability fluctuated seasonally, with evident socio-economic gradient: in the early pre-harvest season food stocks of poor households were 6.5 times smaller than those of better-off families (P < 0.001 by ANOVA). Unlike rich households, poor families markedly decreased the time devoted to agriculture in the pre-harvest season. Crop selection, quality of land management and time employed in agricultural work might have synergistically concurred to cause the stress situation.

The nutritional impact of seasonality in children and adults of rural Ethiopia

A survey of the nutritional status of subsistence farmers was conducted over 13 months in a rural area of Ethiopia characterized by moderate climatic seasonality and intensive land exploitation. Bi-monthly questionnaires on food consumption, time allocation, agricultural production and cash flow were administered to 203 households and anthropometry performed on 1407 individuals. Comparison of post-harvest and pre-harvest anthropometry was made on 672 individuals (48% of the sample). In children, seasonal changes in the Z-score of weight-for-height were small and not significant. Height growth velocity showed instead a marked seasonal pattern, with values close to normal (-0.2 SD units) in July to December, a period characterized by better food availability, and lower values (-3.0 SD units) in January to June, a period characterized by intensive farm labour and heavy rains. Among the adults, body weight was highest in the post-harvest season (December) and decreased by 1.5 +/- 2.3 kg in men and 1.3 +/- 2.6 kg in women to the yearly minimum in the pre-harvest season (June). The paper shows that in this area children and adults both suffer from exposure to seasonal energy stress. The change in weight-for-height Z-score observed in children and the body weight loss observed in adults was greater in individuals of low socio-economic status and, within the same socio-economic level, in individuals with better nutritional status.

Food sources of nutrients of the diet of elderly Italians: II. Micronutrients

The foods which contribute most to the intake of selected vitamins and minerals were evaluated for the elderly in Italy and compared to food sources of nutrients in the US. A sample of 945 Italians, aged > or = 60, from 14 centres throughout Italy, each completed weighed 7-day food records during the period 1983-1987. These data were used to quantify the contribution of individual foods to the total intake of and variability in intake of vitamin A, thiamin, riboflavin, vitamin C, calcium, and iron. In addition, those foods contributing most to micronutrient intake for the Italians were compared to those foods contributing most for the elderly in the US as recorded by the NHANES II Survey (1976-1980). Overall, there was a preponderance of vegetable rather than animal sources, and of less processed food sources in Italy. In Italy, wine was an important source of several nutrients, including iron and riboflavin. These data are useful for characterizing diet in a well-nourished population with marked differences in diet from the US. They may also form the basis for a quantitative food frequency questionnaire for epidemiological studies in Italy.

Food sources of nutrients in the diet of elderly Italians: I. Macronutrients and lipids

The major sources of macronutrients in the Italian diet were assessed. Elderly Italians, aged > or = 60 recorded their weighed intake for a 7-day period. A total of 945 subjects from 14 centres throughout Italy participated during the period 1983-1987. These data were used to quantify the contribution of individual foods to the total intake of and variability in intake of kilocalories, protein, carbohydrate, total fat, saturated fat, oleic acid, polyunsaturated fatty acids, linoleic acid, and cholesterol. The foods ranked one to five for Italy were compared to the top five foods contributing to these nutrients in the diet of the elderly in the US based on the NHANES II Survey (1976-1980). These data provide information for the design of an Italian data-based quantitative food frequency questionnaire. They are also of interest in their description of an industrialized, well-nourished population with a dietary pattern markedly different from the US--lower in saturated fat, higher in complex carbohydrate and higher in alcohol.

Bone turnover in malnourished children

Pyridinoline (PYD) and deoxypyridinoline (DPD) are cross-linking aminoacids of collagen that are located mainly in bone and cartilage. When bone matrix is resorbed these cross-links are quantitatively excreted in the urine and therefore represent specific markers. We have measured the urinary excretion rate of PYD and DPD in 46 severely malnourished boys to assess their skeletal turnover and to relate this to their subsequent rate of growth. The children were aged 13 months (SD 6), and height-for-age was -3.6 (1.6) Z-score, and weight-for-height was -2.4 (0.8) Z-score. PYD excretion when malnourished and after "recovery" was 11.2 (4.6) nmol h-1m-2 and 32.2 (10.8) nmol h-1m-2 and DPD excretion was 2.6 (1.3) nmol h-1m-2 and 7.5 (3.0) nmol h-1m-2, respectively. The ratio of the two cross-links did not change with recovery. These data show that cartilage and bone turnover is much lower in the malnourished than in the recovered child. There was no difference in the degree of depression of turnover between the children with marasmus, marasmic-kwashiorkor, or kwashiorkor. The rate of height gain during recovery was significantly related to cross-link excretion, age, and weight-for-height on admission. These three factors accounted for 44% of the variance in the height velocity of the children. PYD and DPD excretion rate could be used to assess therapeutic interventions designed to alleviate stunting.

Salicylate hydroxylation as an early marker of in vivo oxidative stress in diabetic patients

In vivo metabolism of salicylic acid produces two main hydroxylated derivatives (2,5- and 2,3-dihydroxybenzoic acid). The former can be produced by enzymatic pathways through the cytochrome P-450 system, while the latter is reported to be solely formed by direct hydroxyl radical attack. Therefore, measurement of 2,3-dihydroxybenzoate, following oral administration of salicylate in its acetylated form (aspirin), has been proposed for assessment of oxidative stress. In this article we report plasma levels of 2,3- and 2,5-dihydroxybenzoates following the administration of 1 g aspirin and plasma levels of thiobarbituric acid-reactive material (TBARM) in well-controlled diabetic patients and in healthy subjects. 2,3-Dihydroxybenzoate levels were significantly higher (23%) in diabetic patients than in controls (63.4 +/- 20.1 versus 49.0 +/- 6.8 nM; p < .05). On the other hand, TBARM values were not significantly different between groups. These results suggest that the method is useful to reveal in vivo oxidative stress independently from the peroxidation of lipids, and they support the hypothesis that oxygen radicals are involved in the pathogenesis of chronic complications of diabetes.

A simplified approach of assessing adult chronic energy deficiency

Body mass index (BMI) in conjunction with indices of energy turnover, e.g. physical activity levels (PAL), was recently proposed for classifying adult chronic energy deficiency (CED). Three deprived populations in Africa and Asia were chosen to assess the classification system. Repeated monitoring showed that the combined indicator was affected by instability in PALs and produced implausible discontinuities in the prevalence of different grades of CED. The use of BMI alone produced coherent data with changing BMI distributions, and only 5% of the population would have been wrongly classified as being malnourished, because of being thin but active. The risk of misclassification would be even smaller for populations with BMI distribution shifted towards the right. The prevalence of CED was consistently related within each country to indices of socio-economic status. Yet in Zimbabwe 18% of women and 6% of men had Grade I obesity compared with 11% and 14%, respectively, with CED. Less than 1% Indian and Ethiopian adults were obese but 61% of women and 70% of men were classified as CED in India and 57% and 50%, respectively, in Ethiopia. We propose that adult BMI alone is sufficient to provide important new insights into the problems of food availability and its control in less developed countries.

Body composition and body hydration in old age estimated by means of skinfold thickness and deuterium dilution

In this study a group of 30 women and 30 men aged 60-90 years was examined. Body density was predicted from the sum of four skinfold thickness (SFT) as described by Durnin and Womersley (1974). Body composition, expressed as a percentage of total body weight as fat mass (FM) and fat free mass (FFM) was calculated by means of Siri's formula (Siri 1961). Total body water (TBW) was measured from the dilution of an oral deuterium dose and FFM calculated assuming a hydration of 73.2%. The FM% predicted from SFT showed a slight but not significant decreasing age trend from 28.3% to 25.4% in men, and from 40.3% to 37.8% in women. Body hydration (about 50% of body weight in men and 44% in women) remained constant throughout the age range. FFM obtained from TBW assuming a constant hydration of FFM, was found to be unchanged with age. FM% predicted from SFT was correlated with values obtained from TBW on an individual basis (R2 = 0.38; p less than 0.0001 in men and R2 = 0.31; p less than 0.002 in women), but the scatter was large. The Bland and Altman statistical analysis (Bland and Altman 1986) suggests that the discrepancy between the two estimates tends to be significantly more positive with increasing fatness of the subject. The assumption of a constant hydration of FFM between individuals and with advancing age was tested. The hydration of FFM was calculated as the ratio between TBW (from deuterium dilution) and FFM (estimated from SFT). The wide range of values (50% to 90%) suggests large inter-individual differences. The mean values were lower than commonly reported, and differed with age and sex. In men, FFM hydration steadily decreases with age from the 7th decade (70.2 +/- 7.7%) to the 10th decade (65.9 +/- 8.2%). Women showed higher average figures than those of men and a lower age-associated decline (72.5% and 68.5% respectively). Our results suggest that FFM hydration decreases with age, and this indicates the need to develop age-related correction factors in order to derive FFM from TBW in an elderly population.

Nutritional status: serum lipids. Euronut SENECA investigators

Serum lipid levels are considered to be one of the main risk factors for cardiovascular diseases in middle-aged men and women. The significance, however, of serum lipid metabolism as a cardiovascular disease risk factor in the elderly has yet to be clarified. This paper focuses upon the serum lipid levels of groups of elderly people from 18 centres with diversified socioeconomic backgrounds in 11 European countries. Serum cholesterol was measured with an enzymatic colorimetric method by autoanalyser in one laboratory and accuracy was checked by participation in the quality control programme of the Centre for Disease Control, Atlanta, GA, USA. Mean (+/- SD) serum cholesterol levels ranged from 6.56 +/- 0.66 mmol/l (Bellinzona, Switzerland) to 5.22 +/- 0.68 mmol/l (Coimbra, Portugal) in men, and in women from 7.77 +/- 1.61 mmol/l (Elverum, Norway) to 5.86 +/- 1.07 mmol/l (Anogia-Archanes/Greece). The mean levels of high-density lipoprotein (HDL) cholesterol ranged from 1.40 +/- 0.58 mmol/l (Chateau Renault-Amboise, France) to 1.05 +/- 0.28 mmol/l (Elverum, Norway) in men and from 1.62 +/- 0.41 mmol/l (Padua, Italy) to 1.23 +/- 0.29 mmol/l (Anogia-Archanes, Greece; Vila Franca de Xira, Portugal) in women. The highest median serum triglyceride values were found in Norway (Elverum) (men: 1.50 mmol/l, women: 1.75 mmol/l), and one of the French groups (Chateau Renault-Amboise) had the lowest median values (men: 1.07 mmol/l, women: 1.15 mmol/l). Significant differences between participating centres and between sexes were found for the following variables: serum cholesterol, HDL, and the ratio total HDL cholesterol/total cholesterol. For triglycerides the differences were significant only between centres, not between the sexes.(ABSTRACT TRUNCATED AT 250 WORDS)