Reproducibility and relative validity of a brief quantitative food frequency questionnaire for assessing fruit and vegetable intakes in North-African women.

BACKGROUND: In the context of a rapidly increasing prevalence of noncommunicable diseases, fruit and vegetables could play a key preventive role. To date, there is no rapid assessment tool available for measuring the fruit and vegetable intakes of North-African women. The present study aimed to investigate the reproducibility and relative validity of an eight-item quantitative food frequency questionnaire that measures the fruit and vegetable intakes (FV-FFQ) of Moroccan women. METHODS: During a 1-week period, 100 women, living in the city of Rabat, Morocco (aged 20-49 years) completed the short FV-FFQ twice: once at baseline (FV-FFQ1) and once at the end of the study (FV-FFQ2). In the mean time, participants completed three 24-h dietary recalls. All questionnaires were administered by interviewers. Reproducibility was assessed by computing Spearman's correlation coefficients, intraclass correlation (ICC) coefficients and kappa statistics. Relative validity was assessed by computing Wilcoxon signed-rank tests and Spearman's correlation coefficients, as well as by performing Bland-Altman plots. RESULTS: In terms of reproducibility, Spearman's correlation coefficient was 0.56; ICC coefficient was 0.68; and weighted kappa was 0.35. In terms of relative validity, compared with the three 24-h recalls, the FV-FFQ slightly underestimated mean fruit and vegetable intakes (-10.9%; P = 0.006); Spearman's correlation coefficient was 0.69; at the individual level, intakes measured by the FV-FFQ were between 0.39 and 2.19 times those measured by the 24-h recalls. CONCLUSIONS: The brief eight-item FV-FFQ is a reliable and relatively valid tool for measuring mean fruit and vegetable intakes at the population level, although this is not the case at the individual level.

The acceptability to stakeholders of mandatory nutritional labelling in France and the UK--findings from the PorGrow project.

BACKGROUND: Implementing a European Union (EU)-wide mandatory nutrition labelling scheme has been advocated as part a multi-pronged strategy to tackle obesity. The type of scheme needs to be acceptable to all key stakeholders. This study explored stakeholders' viewpoints of labelling in two contrasting food cultures (France and the UK) to see whether attitudes were influenced by sectoral interests and/or national context. METHODS: Using Multi Criteria Mapping, a decision analysis tool that assesses stakeholder viewpoints, quantitative and qualitative data were gathered during tape-recorded interviews. In France and the UK, 21 comparable stakeholders appraised nutritional labelling with criteria of their own choosing (i.e. feasibility, societal benefits, social acceptability, efficacy in addressing obesity, additional health benefits) and three criteria relating to cost (to industry; public sector; individuals). When scoring, interviewees provided both optimistic (best case) and pessimistic (worst case) judgements. RESULTS: Overall, mandatory nutritional labelling was appraised least favourably in France. Labelling performed worse under optimistic (best case) scenarios in France, for five out of eight sets of criteria. French stakeholders viewed labelling as expensive, having fewer benefits to society and as being marginally less effective than UK stakeholders did. However, French interviewees thought implementing labelling was feasible and would provide additional health benefits. British and French stakeholders made similar quantitative judgements on how socially acceptable mandatory labelling would be. CONCLUSIONS: There is agreement between some stakeholder groups in the two different countries, especially food chain operators. However, cultural differences emerged that could influence the impact of an EU-wide mandatory labelling scheme in both countries.

Health and behaviours of Tunisian school youth in an era of rapid epidemiological transition.

To assess youth health behaviours and related quality of life in urban Tunisia, we conducted a cross-sectional survey of a representative sample of 699 secondary-school students. The overweight rate was 20.7%. Most of the sample had an insufficient level of physical activity and were unfamiliar with the recommended frequency of moderate physical activity. Norm-based scores of psychological state were about average, slightly better for boys than girls. Girls perceived themselves to be more stressed than boys. Of all students, 35% declared having smoked a cigarette and 14% having drunk alcohol at least once in their lives. The main sources of health education were mass media (59%) and medical staff (36%).

Stakeholder views on policy options for responding to the growing challenge from obesity in France: findings from the PorGrow project.

To explore the perspectives of key stakeholders towards a range of policy options to prevent obesity in France, a multi-criteria mapping method was used to gather quantitative and qualitative data from 21 types of stakeholder groups. During structured interviews, stakeholders appraised a set of pre-defined options by reference to criteria of their own choosing and provided relative weights to their criteria, and overall rankings of the policy options. Efficacy, feasibility and societal benefits were the groups of criteria given most importance by stakeholders. There was most consensus and preference for options related to health education, particularly in schools, compared with options that aimed at changing the environment to prevent obesity, i.e. options around physical activity; options that modified food supply and demand; and information-related options. There was little support for technological solutions or institutional reforms. While there was broad interest in a range of different options, those related to behaviour change through education were the most valued by stakeholders. Raising awareness among policymakers about the convincing scientific evidence for the effectiveness of environmental level policy options will be a crucial first step.

Use of variety/diversity scores for diet quality measurement: relation with nutritional status of women in a rural area in Burkina Faso.

OBJECTIVES: To develop scores for food variety and diversity to assess the overall dietary quality in an African rural area; and to study their relationship with the nutritional status of women of childbearing age. DESIGN: Cross-sectional. SETTING: Sahelian rural area in the North-East Burkina Faso (West Africa). SUBJECTS: A total of 691 mothers with children below the age of 5 y, selected at random in 30 villages. METHODS: A qualitative recall of women's food consumption during the previous 24 h made it possible to calculate a food variety score (FVS = count of food items consumed) and a dietary diversity score (DDS = count of food groups, among 14 groups). These scores were then divided into terciles. Body mass index (BMI), mid-upper arm circumference (MUAC) and body fat percentage (BFP) were used to determine the women's nutritional status. RESULTS: The overall dietary quality was poor: mean FVS (s.d.) = 8.3 (2.9) food items; mean DDS = 5.1 (1.7) food groups. A clear relationship was shown between both FVS and DDS (in terciles) and most nutritional indices. Women with a FVS in the lowest tercile had a mean BMI of 20.1, while those in the highest tercile had a BMI of 20.9 (P = 0.009). Those in the lowest tercile of DDS had a 22.8% prevalence of underweight vs 9.8% in the highest tercile (P < 0.0001). The latter relationship remained significant even when the subjects' sociodemographic and economic characteristics were accounted for. CONCLUSION: Dietary scores measured at the individual level are good proxies for overall dietary quality of women living in a poor rural African area. These scores were also shown to be linked with the nutritional status of women. FINANCING: IRD financed the study with the assistance of UNICEF for the purchase of anthropometric equipment. The first author received a research allowance from the French Ministry of Research through the doctoral school 393 of Pierre and Marie Curie University (Paris VI).

Effect of fiber in sorghum on nitrogen digestibility.

Digestibility measurements were carried out on a population of 12 Cameroonians whose habitual diet, deficient in animal products, is based on consumption of sorghum meal which supplies between 2.4 and 4.2 g of crude fiber per 100 g of dry matter. Over an 11-day period, the 12 subjects received successive diets of 3.3, 4.8, and 5.4 g of crude fiber per 100 g of dry matter. The increase in fiber intake resulted in a significant rise in quantity of fecal matter excreted, including nitrogen and formic insoluble substances. On the other hand, the highest urinary nitrogen losses were obtained from the diet least rich in fiber. The apparent digestibility of nitrogen dropped from 65.4 to 60.5% and then further to 56.9%. The apparent digestibility of nitrogen of the diet least rich in fiber differed significantly from those of the other two diets. The subjects under study did not benefit from an adaptive physiology which would enable them to reduce digestive nitrogen losses. Intestinal disappearance of crude fiber augmented significantly and then stabilized when switching from the diet least rich in fiber to the two others, i.e., from 15.1 to 19.9 g/day and then 19.8 g/day. This population was distinguished by its ability to breakdown large quantities of fiber and to reduce urinary nitrogen loss when fecal nitrogen output rises. Apparent nitrogen balances remained positive.

Effect of early, short-term supplementation on weight and linear growth of 4-7-mo-old infants in developing countries: a four-country randomized trial.

The effect of supplementation on growth was tested by means of four similar controlled randomized trials in the Congo (n = 120), Senegal (n = 110), Bolivia (n = 127), and New Caledonia (n = 90). Four-month-old infants were randomly allocated to supplement or control groups. A cereal-based precooked porridge was offered twice daily for 3 mo and consumption was monitored. Both groups were free to eat local food. At 7 mo of age, all infants were still breast-fed in the Congo, Senegal, and Bolivia compared with 47% in New Caledonia. Mean daily consumption of the supplement varied among countries (558-790 kJ/d). Mean length at 4 mo was lowest in Bolivia, higher in Senegal and the Congo, and near the National Center for Health Statistics reference in New Caledonia. The mean 4-7 mo length increment was 0.48 cm higher for supplemented than for control infants in Senegal (P < 0.05), whereas weight increments did not differ. No significant effect was found in the other countries.

PIP: Findings from this study of the link between nutritional supplementation during breast feeding and infant growth disagree with earlier studies. The effect of nutritional supplementation on growth in length was only modest, but significant only in Senegal and not significant in the Congo, Bolivia, and New Caledonia. It is hypothesized that food supplementation during the 4-7 month period would have a positive effect on linear growth. This study included four controlled randomized trials among 120 infants in the Congo, 110 infants in Senegal, 127 infants in Bolivia, and 90 infants in New Caledonia. The infants were 4 months old when placed in the supplement or control groups. Supplementation included the addition of a cereal-based precooked porridge twice daily for 3 months. Both groups continued to eat local foods. Breast feeding patterns were different in New Caledonia, where only 47% of infants were still breast fed at 7 months of age. Mean daily supplementation varied among countries, from 558 to 790 kJ/day. Mean length was lowest in Bolivia, higher in Senegal and the Congo, and close to the US National Center for Health Statistics reference measures in New Caledonia. The study was conducted in rural parts of Senegal and New Caledonia and periurban parts of Bolivia and the Congo. Supplementation was supervised by field workers. The samples included infants with a length-for-age score of -2.5 or higher and a weight-for-length Z score of -2 or higher at 4 months. Anthropometric measurements were taken at 4 months and 4, 8, and 13 weeks later (at 4.9, 5.8, and 7.0 months of age). 24-hour food recalls were collected monthly for consumption of breast milk, special local infant food, commercial "western" baby food, milk substitutes, family food, water, and other than milk liquids.

Decreased attendance at routine health activities mediates deterioration in nutritional status of young African children under worsening socioeconomic conditions.

BACKGROUND: Economic crisis and sociopolitical instability are generally associated with worsening health and nutrition in developing countries. This study examines the role played by the attendance rate of young children at routine health activities in the deterioration of their nutritional status under adverse social and economic conditions. METHODS: Two nutritional cross-sectional surveys were carried out in two districts of Brazzaville, capital city of The Congo, in 1993 and 1996. They included respectively 2807 and 1695 randomly selected children 4--23 months old. The children's nutritional status was assessed by height-for-age in z-scores. Using embedded general linear regression models, explanatory variables (routine health activities index, socio-demographic context, household economic level, prenatal factors) were tested as potential mediators for the effect of the year of survey on child mean height-for-age. RESULTS: The routine health activities index declined sharply from 1993 to 1996. Its introduction in the regression model including all other explanatory variables led to a sharp decrease in the effect of the year on children's nutritional status, showing the important mediating effect of routine health activities. This result was encountered across all economic categories of households. Other explanatory variables showed more limited mediating effect. CONCLUSIONS: Attendance at preventive health activities should be fostered in African urban communities facing harsh socioeconomic situations to prevent further deterioration in the nutritional status of children.

Nutritional change and economic crisis in an urban Congolese community.

BACKGROUND: In 1986, the government of Congo undertook a structural adjustment programme to cope with the economic crisis. We present the results of a study whose objectives were to assess the evolution of nutritional status of an urban community between 1986 and 1991 and to identify specific groups for which the nutritional status may have worsened. METHODS: Two cross-sectional surveys were carried out on representative samples of Brazzaville children < 6 years old: 2295 children were surveyed in 1986 and 2373 in 1991. Anthropometric assessment of nutritional status was performed. For children, weight-for-height and height-for-age indices were used according to WHO recommendations. Wasting and stunting were respectively defined as indices under -2 z-scores. Body mass index of mothers was calculated and risk of chronic energy deficiency (CED) was defined as < 18.5 kg/m2. Socioeconomic data relative to the households were also collected. Multivariate statistical methods were used to obtain adjusted estimates of nutritional changes in the community. RESULTS: Data analysis led to several converging results: increase in the percentage of low birthweight (10.2% in 1985 versus 18.7% in 1990), increase in the percentage of CED (from 7.9% to 10.5%), and increase in the prevalence of wasting (from 2.9% to 4.2%). By contrast, the overall prevalence of stunting decreased from 13.9% to 11.0%. After statistical adjustment, the factors found to influence the evolution of anthropometric status were: age of child, age of mother, schooling of mother and household characteristics such as number of preschool children, economic level and head of household's occupation. CONCLUSIONS: The study enables the negative effects of the economic crisis to be quantified. Body mass index is shown to be sensitive to economic changes. It could be recommended as a possible indicator for monitoring the nutritional status at population level. The results also call for a new impetus in preventive health programmes and the implementation of nutritional surveillance activities.

PIP: In the face of an economic crisis, the government of Congo in 1986 embarked upon a structural adjustment program. A study was later conducted to assess the evolution of nutritional status in an urban community during 1986-1991, and to identify specific groups for which nutritional status may have worsened. The authors present the results of this study. 2295 children in Brazzaville younger than 6 years of age were surveyed in 1986 and 2373 in 1991. Anthropometric assessment of nutritional status was performed and child weight-for-height and height-for-age indices used according to World Health Organization recommendations. Socioeconomic data relative to the households were also collected. Between 1985 and 1990, the degree of low birth weight increased from 10.2% to 18.7%, chronic energy deficiency from 7.9% to 10.5%, and the prevalence of wasting from 2.9% to 4.2%. The overall prevalence of stunting, however, decreased from 13.9% to 11.0%. After statistical adjustment, child's age, mother's age, mother's schooling, and household characteristics such as the number of preschool children, economic level, and head of household's occupation were found to influence the evolution of anthropometric status. Body mass index has therefore been shown to be sensitive to economic changes and could thus be recommended as a possible indicator for monitoring nutritional status at the population level. Study results also call for a new impetus in preventive health programs and the implementation of nutritional surveillance activities.

Detection of moderate protein-energy malnutrition in pre-school children.

Several biochemical and anthropometric tests were used to define the states of mild or moderate protein-energy malnutrition among 810 children aged under five years in the forest region of Southern Cameroon. The results show that the percentage and the identity of children classified as undernourished may be different according to the anthropometric test employed. The mean values of most of the biochemical variables assayed decrease in the groups affected with moderate weight and arm deficiencies. A system is proposed for the evaluation of the nutritional status based on the simultaneous use of four anthropometric tests. Some biochemical parameters may be useful for establishing a diagnosis.

Use of hand-to-hand impedancemetry to predict body composition of African women as measured by air displacement plethysmography.

OBJECTIVES: To test the validity of a simple, rapid, field-adapted, portable hand-held impedancemeter (HHI) for the estimation of lean body mass (LBM) and percentage body fat (%BF) in African women, and to develop specific predictive equations. DESIGN: Cross-sectional observational study. SETTINGS: Dakar, the capital city of Senegal, West Africa. SUBJECTS: A total sample of 146 women volunteered. Their mean age was of 31.0 y (s.d. 9.1), weight 60.9 kg (s.d. 13.1) and BMI 22.6 kg/m(2) (s.d. 4.5). METHODS: Body composition values estimated by HHI were compared to those measured by whole body densitometry performed by air displacement plethysmography (ADP). The specific density of LBM in black subjects was taken into account for the calculation of %BF from body density. RESULTS: : Estimations from HHI showed a large bias (mean difference) of 5.6 kg LBM (P<10(-4)) and -8.8 %BF (P<10(-4)) and errors (s.d. of the bias) of 2.6 kg LBM and 3.7 %BF. In order to correct for the bias, specific predictive equations were developed. With the HHI result as a single predictor, error values were of 1.9 kg LBM and 3.7 %BF in the prediction group (n=100), and of 2.2 kg LBM and 3.6 %BF in the cross-validation group (n=46). Addition of anthropometrical predictors was not necessary. CONCLUSIONS: The HHI analyser significantly overestimated LBM and underestimated %BF in African women. After correction for the bias, the body compartments could easily be estimated in African women by using the HHI result in an appropriate prediction equation with a good precision. It remains to be seen whether a combination of arm and leg impedancemetry in order to take into account lower limbs would further improve the prediction of body composition in Africans.

Body composition unaltered for African women classified as 'normal but vulnerable' by body mass index and mid-upper-arm-circumference criteria.

OBJECTIVE: To test the hypothesis that 'normal but vulnerable' adults, as defined by body mass index (BMI) in combination with mid-upper-arm-circumference (MUAC), are closer to normal than to malnourished ones. For that purpose body composition measurements were compared between normal and low BMI categories and according to MUAC value in an African context and for different age groups. DESIGN: Reanalysis of data from a previous cross-sectional cluster sample nutrition survey. SETTING: A rural area of the Republic of Congo, Central Africa. SUBJECTS: A representative sample (n=544) of non-pregnant women. MAIN OUTCOME MEASURES: Arm muscle area was calculated from measurements of triceps skinfold thickness and MUAC. Peripheral body fat was assessed by the sum of four skinfold thicknesses. The ratio of resistance at high and low frequencies was derived from whole body measurement of multifrequency bioelectrical impedance analysis and used as the extracellular to total body water ratio index. RESULTS: The prevalence of thinness decreased from 18.7% as defined by BMI alone to 9.0% as defined by BMI and MUAC. This difference was due to the group of subjects classified as 'normal but vulnerable' (9.7%). Prevalence of thinness increased with age when assessed by BMI alone, but no longer when assessed by BMI and MUAC. Comparison with the BMI> or =18.5 kg/m(2) category showed that in 'normal but vulnerable' subjects lower BMI was accompanied by lower both fat and lean compartments, in absolute values, but the equilibrium of body water compartments was not altered. In BMI<18.5 women, low MUAC was associated with altered lean tissues, at peripheral and whole body level, whereas fat tissue did not differ. CONCLUSIONS: 'Normal but vulnerable' subjects appeared as 'thin but healthy' rather than malnourished, at all ages, even though their BMI was lower than 18.5 kg/m(2). The new classification of thinness based on BMI and MUAC provides a more specific index of nutritional status when restricting the thin category to more at-risk subjects.

Is body mass index sensitively related to socio-economic status and to economic adjustment? A case study from the Congo.

Several nutritional surveys based on representative samples from various urban and rural situations show that the Congo presents a situation of nutritional transition. There is a large prevalence of low body mass index (BMI) in adults from rural zones and this increases with age. There is, however, a large prevalence of high BMI in urban populations despite the persistence of some degree of chronic energy deficiency (CED), particularly at younger ages. Correspondence analysis and logistic regression were used to construct a socio-economic index and measure adjusted risk factors for CED. In rural areas, the major risk factors were old age, sex (women) and the absence of schooling; low economic status, a commonly shared factor, did not differentiate between households for CED. In Brazzaville, CED was linked to a young age (< 30 years) and, clearly, to poverty. The change in the prevalence of CED in mothers from the capital city during a period of economic adjustment showed an increased incidence in young mothers, and also showed that the disparity between low and high economic levels regarding CED had grown. Finally, there was a high level of correspondence between the mean values for the weight-for-height of children and the BMI categories of the mothers. There is a parallel evolution during the period of economic adjustment between the increase of wasting in infants and the increase of CED in mothers. Therefore BMI appears to be a potential core indicator for use in nutritional surveillance in the Congo.

Bioelectrical impedance analysis in small- and appropriate-for-gestational-age newborn infants.

OBJECTIVE: To determine the reliability of bioelectrical impedance analysis, and to compare and contrast the anthropometric and BIA status of newborns. DESIGN: BIA and anthropometric parameters were compared in the few days after birth and at about 3 weeks of age. SETTING: At the maternity hospital or in a paediatric care unit. SUBJECTS: Small- or appropriate-for-gestational-age newborns, with birth weight below or above the 10th percentile of the reference value, respectively. Measurements were performed on 36 and 47 newborns at birth, and for a subgroup (21 and 11) again about 3 weeks later, respectively. RESULTS: At birth, length2/resistance was 4.3 +/- 0.6 and 6.1 +/- 1.2 cm2/omega (P = 10(-7)), and at 3 weeks of age length2/resistance was 5.0 +/- 0.6 and 5.7 +/- 0.8 cm2/omega (P = 0.11), for small- and appropriate-for-gestational-age newborns, respectively. Percentage reliability was 2.2% and 2.6% for intra- and inter-observer measurements of resistance. Importance of a correct placement of the sensor electrode was demonstrated. CONCLUSIONS: Ease of measurement and reliability of BIA in neonates were shown. Evolution of BIA values is in agreement with the known increase in total body water linked to regrowth of cell mass in small-for-gestational-age infants. Additional study is required before BIA should be used in usual clinical setting in newborns due to the lack of prediction equation.

Change in body water distribution index in infants who become stunted between 4 and 18 months of age.

OBJECTIVE: To evaluate body composition changes using bioelectrical impedance analysis and skinfold thickness measurements in infants from tropical areas who become stunted between 4-18 months of age. DESIGN AND MEASUREMENTS: Follow-up study. Extracellular water to total body water ratio index (length(2)/resistance at low to high frequency), peripheral fat (tricipital and subscapular skinfold thickness), and length-for-age index were studied at 4 and 18 months of age. SETTINGS: Low-income areas in four tropical regions (Congo, Senegal, Bolivia and New Caledonia). SUBJECTS: Infants were included in the analysis provided they were neither stunted nor wasted at 4 months. Two groups of infants were compared, those that were stunted at 18 months (n=61) or not (n=170). RESULTS: The extracellular water to total body water ratio index and the sum of skinfold thickness measurements were similar in the two groups at 4 months, and only the extracellular water to total body water ratio index was significantly different at 18 months. When no stunting appeared between 4 and 18 months, the change in the extracellular water to total body water ratio index was not linked with variations in length-for-age, and presented the expected pattern of variation in body water compartments. When stunting occurred, variation in length-for-age was related to significant changes in the extracellular water to total body water ratio index, the biggest increase in the proportion of extracellular water being found in the most stunted infants. Variations in the sum of the two skinfold thickness measurements presented the expected pattern for the 4-18 months growth and did not differ between the two groups. CONCLUSIONS: Multifrequency resistances suggested that stunting was associated with a lack of the expansion of the intracellular compartment that is expected during normal growth of cell mass, together with preserved fat mass. SPONSORSHIPS: Supported by grant 92L0623 from the French Ministry of Research, and by Institut de Recherche pour le Développement (IRD).

[Logistic regression vs other generalized linear models to estimate prevalence rate ratios]. / Régression logistique vs autres modèles linéaires généralisés pour l'estimation de rapports de prévalences.

In cross-sectional studies, to quantify the association between a risk factor and a disease (possibly adjusted for confounders), in the framework of the multiplicative model, the more obvious effect measure is a prevalence rate ratio with an associated confidence interval. The validity of this confidence interval requires an unbiased estimator and an appropriate estimate of the variance. In numerous epidemiological studies however, routine use is made of odds ratios and logistic regression. As the odds ratio per se is difficult to understand, prevalence odds ratios are often interpreted as prevalence rate ratios. But this latter approximation is valid only under the rare disease assumption. Moreover, in the logistic regression model, the variance of the estimates is based on the assumption of binomial variability, which is not always supported by the data; in the frequent case of overdispersion, this leads to under-estimation of the type I error rate. Yet, within the generalized linear model, it is easy to choose a link function other than the logit. For example, the log link (log-binomial model) is appropriate to directly estimate adjusted prevalence rate ratios. In case of overdispersion, it is also possible to achieve a better fit of the model, either by choosing another distribution in the exponential family or by estimating a dispersion parameter for the binomial distribution. Thus, there are no valid reasons for the systematic choice of odds ratio and of the logistic regression model to estimate prevalence rate ratios, unless the type of study imperatively requires their use.

[Urbanization and nutritional transition in sub-saharan Africa: exemplified by Congo and Senegal]. / Urbanisation et transition nutritionnelle en Afrique Sub-Saharienne: les exemples du Congo et du Sénégal.

To evaluate the impact of urban life-style on nutritional status, body mass index (BMI) of mothers and indices of malnutrition of preschool children were calculated in four representative surveys in two rural areas and two main cities of Western and Central Africa. Mean BMIs were similar in both urban settings and were significantly higher than those of rural mothers. Distributions shifted significantly towards values over 25 kgs/m2 in towns, although, values lower than 18.5 were still present. Therefore chronic energy deficiency, largely prevalent in many rural areas of Africa, remains important in cities, where obesity also appears to have become a public health concern. Wasting was rare in young urban children, but the prevalence of stunting, although lower, indicates the persistence of nutritional deficiencies. This situation of nutritional transition generates a double burden to already limited health finances and requires an appropriate educational policy.

[Obesity and developing countries of the south]. / Obésité et développement des pays du sud.

An adult is considered as overweight if his body mass index is 25.0 kg/m2 or more and as obese if it is 30.0 kg/m2 or more. Since excess weight is a predisposing factor for many chronic diseases, e.g. diabetes, an increase in its incidence in the population is cause for concern. Until now, excess weight has been problem of epidemic proportions only in developed countries, but it has recently spread to the developing world. More than 30% of the population in Latin America, the Caribbean, the Middle East, and Northern Africa is overweight. Populations living on Pacific and Indian Ocean islands have the highest prevalence of obesity in the world. In Asia and Black Africa, the overall prevalence of overweight is still low but incidence is high in urban areas. In most of these countries, both underweight and overweight people can now be seen. In many countries, the increase in the number of overweight people has occurred within the last few years. Excess weight appears first among the affluent and then among low-income classes including young children and teenagers. The main causes are a nutrition transition to lipid-rich diets and, above all, reduced physical activity in city dwellers. Obesity and associated diseases could become major problems in the future since malnutrition during fetal development and early childhood are predisposing factors. Already overweight is creating an extra burden for countries where malnutrition and nutritional deficiencies are still observed in young children. Given the economic costs of management of obesity-related diseases, surveillance and prevention programs are needed to stem the growth of this problem.

[Nutrition, urbanization and poverty in subsaharan Africa]. / Nutrition, urbanisation et pauvreté en Afrique subsaharienne.

Africa is currently the continent with the highest urbanization rate in the world. This demographic upheaval has sometimes been considered as an opportunity for modernization but as early as the 1980s experts called attention to its potential impact on nutrition. In recent decades, economic problems and structural reforms have had dire effects on urban populations. Today increasing poverty and the effects of globalization have revived concerns about urban nutrition. Retarded growth and emaciation are less common than in urban areas than in rural areas, but disparities between the rich and poor are much greater. However, in some cities, the incidence of emaciation progressed the more during the 1990s, and now equals that in rural areas. In cities the level of obesity in adult women is a sign of nutritional transition but emaciation has also increased. Despite the wide variety of urban conditions, analysis of the underlying factors reveals several constants. For most of these factors, the characteristic feature of the urban environment is a further increase of social inequality.

[The "malnutrition-infection" complex, the most widespread public health problem in underprivileged populations.]. / Le complexe "malnutrition-infection" : premier problème de santé publique chez les populations défavorisées.

The synergistic association between malnutrition and infection remains today the most worrisome public health problem in the world. Although the high level of mortality among children in developing countries is mainly due to infectious and parasitic diseases, more than half of these children die in a state of overt undernourishment. Energy and nutrient deficiencies adversely affect various aspects of immunocompetence, thus malnourished people are particularly sensitive to many opportunistic infections. These, in turn, induce anorexia, various metabolic changes and malabsorption, which affect nutritional reserves, and lead to malnutrition if prolonged. In the absence of efficient measures to break this vicious cycle, malnutrition and morbidity lead to high levels of mortality. Experience from developing countries suggests that to improve the prevention and treatment of infectious diseases in such a context of poverty, one need to take into account simultaneously the basic environment of underprivileged groups and their dietary intake as well as their level of access to health care services.