Direct and Indirect Determinants of Body Mass Index in Both Major Ethnic Groups Experiencing the Nutritional Transition in Cameroon.

In the context of rapid nutritional transitions in Africa, few studies have analyzed the etiology of obesity by considering the driver pathways that predict body mass index (BMI). The aim of this study is to innovatively identify these driver pathways, including the main sociodemographic and socioecological drivers of BMI. We conducted a rural-urban quantitative study in Cameroon (n = 1106; balanced sex ratio) to explore this issue. We recruited participants and reported several sociodemographic characteristics (e.g., marital status, socioeconomic status (SES), and ethnicity). We then assessed three main socioecological drivers of BMI (body weight perception, dietary intake, and physical activity) and conducted bioanthropometric measurements. We identified several driver pathways predicting BMI. In Cameroon, Bamiléké ethnicity, higher SES, being married, and older age had positive effects on BMI through overweight valorization and/or dietary intake. Accordingly, we found that being Bamiléké, married, and middle-aged, as well as having a higher SES, were factors that constituted at-risk subgroups overexposed to drivers of obesity. As such, this study highlights the necessity of investigating the complex driver pathways that lead to obesity. Therefore, better identification of the subgroups at risk for obesity will help in developing more targeted population health policies in countries where this burden is a major public health issue.

Determinants of energy intake in Central African populations experiencing nutrition transition.

Central Africa is experiencing rapid urbanisation, and this situation comes along with changes in food habits and an increased prevalence of obesity and associated health risks. Factors influencing dietary intake among the diverse African populations are not well understood. Our objective was to characterise the dietary intake and their determinants in the two main ethnic groups experiencing nutrition transition in Cameroon, the Bamiléké and the Béti. We sampled Bamiléké (381) and Béti (347) adults living in both rural and urban, collected socio-demographic variables, assessed dietary patterns by using a food portion photographs book to administrate a FFQ and a 24-h dietary recall technique and derived their BMI from measured weight and height. The dietary patterns of Bamiléké people were composed of more energy-dense foods than the Béti people, regardless of the living area. The energy intake (13·8 (sd 4·6)-15·4 (sd 4·8) MJ v. 9·7 (sd 3·5)-11·2 (sd 3·9 MJ) and the obesity (15-29 % v. 5-8 %) were therefore higher in Bamiléké than in Béti, respectively. Multivariable linear regression analyses showed strong associations of both ethnicities (4·02 MJ; P < 0·001), living area (0·21 MJ; P < 0·001) and education (0·59 MJ; P < 0·048) with energy intake, independently of each other and other socio-demographic factors. The ethnicity factor has been characterised as the more important determinant of diet. Our findings provide new insights and perspectives highlighting the importance of anthropological factors when building prevention campaigns against obesity in Central Africa.

Development and validation of the body shape scale (BOSHAS) for assessing body shape perception in African populations.

BACKGROUND: As a consequence of 'Western' acculturation, eating disorders and body image disturbances, such as fatness phobia and body dysmorphic disorders towards musculature and body shape, are emerging in Africa, with young people the most affected. It is therefore important to accurately assess perceptions of body shape. However, the existing body image assessment scales lack sufficient accuracy and validity testing to compare body shape perception across different African populations. The purpose of this study was to develop and validate the Body Shape Scale (BOSHAS) to evaluate body shape perceptions related body image disorders in African populations. METHODS: To develop the BOSHAS, anthropometric measures of 80 Cameroonians and 81 Senegalese (both sexes included; 40.1% females overall) were taken for three body shape criteria: somatotype components, body mass index (BMI) and waist-to-hip ratio. Subjects were selected to cover a wide variability in body shape and were photographed in full face and profile positions. To validate the BOSHAS, the scale was administered twice (2 weeks apart) to 106 participants (aged 31.2 ± 12.6 years) to assess its reliability. In addition, a questionnaire measuring different aspects of body shape (e.g. musculature) was also administered (n = 597; aged 36.7 ± 15.6 years) to assess its convergent validity. RESULTS: The BOSHAS includes two sex-specific subscales of 10 photographs each. Most participants were able to repeat their BOSHAS preference order. Test-retest reliability was also consistent in estimating Current Body Shape (CBS), Desired Body Shape and Ideal Body Shape for participants and their partners. CBS was correlated with BMI, and different BOSHAS indices were consistent with declarations obtained by questionnaire. CONCLUSIONS: The BOSHAS is the first sex-specific scale of real African models photographed in face and profile, including large body shape variability. The validation protocol showed good validity and reliability for evaluating body shape perceptions and dissatisfaction of Africans.

Physical Activity and Cardiorespiratory Fitness in Tarahumara and Mestizo Adolescents from Sierra Tarahumara, Mexico.

OBJECTIVES: Our purpose was to explore the levels of cardiorespiratory fitness (CRF) and the relationship between CRF, physical activity, and other physical traits in traditional and nontraditional Tarahumara, and Mestizo adolescents from Sierra Tarahumara, Mexico. METHODS: A sample of 87 adolescents aged 16.9 ± 1.2 years (mean ± SD) performed the Margaria step test to quantify CRF. Physical activity was estimated using the International Physical Activity Questionnaire. Blood pressure (BP) and anthropometric measures were taken to estimate body composition and other physical characteristics. RESULTS: Traditional Tarahumara showed higher levels of CRF than nontraditional Tarahumara and Mestizo adolescents (F = 5.5, p = .006). The time allotted to sedentary activities was higher in the Mestizo and nontraditional Tarahumara (χ2 = 10.17, p = .006). In nontraditional Tarahumara, adiposity was associated with CRF reduction (r2 = -.63, p = .00), while vigorous physical activities were positively associated with CRF (r2 = .43, p = .03) and negatively associated with the z-score of body fat (r2 = -.42 p = .03). Finally, CRF was negatively associated with fat percentage (r2 = -.27, p = .00) and systolic blood pressure (r2 = -.09, p = .04) in the Mestizo. In this group, walking activities (r2 = -.25, p = .003) and total physical activity score (r2 = -.11, p = .03) had a positive association with the CRF, while moderate activities had a negative association with the body mass index (r2 = .09, p = .04), and vigorous activities were negatively associated with body weight (r2 = .11, p = .03). CONCLUSIONS: In the sampled nontraditional Tarahumara and Mestizo adolescents, moderate and vigorous physical activities were important factors in determining levels in CRF, fat percentage, and other health parameters.

Biocultural determinants of overweight and obesity in the context of nutrition transition in Senegal: a holistic anthropological approach.

Senegal is experiencing a rising obesity epidemic, due to the nutrition transition occurring in most African countries, and driven by sedentary behaviour and high-calorie dietary intake. In addition, the anthropological local drivers of the social valorization of processed high-calorie food and large body sizes could expose the population to obesity risk. This study aimed to determine the impact of these biocultural factors on the nutritional status of Senegalese adults. A mixed methods approach was used, including qualitative and quantitative studies. Between 2011 and 2013, fourteen focus group discussions (n=84) and a cross-sectional quantitative survey (n=313 women; n=284 men) of adults in three different socio-ecological areas of Senegal (rural: n=204; suburban: n=206; urban: n=187) were conducted. Dietary intake (Dietary Diversity Scores), physical activity (International Physical Activity Questionnaire), body weight norms (Body Size Scale), weight and health statuses (anthropometric measures and blood pressure) were measured. Middle-aged and older Senegalese women were found to value overweight/obesity more than younger Senegalese in all regions. In addition, young urban/suburban adults had a tendency for daily snacking whilst urban/suburban adults tended to be less physically active and had higher anthropometric means. A binary logistic regression model showed that being female, older, living in urban/suburban areas and valuing larger body size were independently associated with being overweight/obese, but not high-calorie diet. Univariate analyses showed that lower physical activity and higher socioeconomic status were associated with being overweight/obese. Finally, overweight/obesity, which is low in men, is associated with hypertension in the total sample. The nutrition transition is currently underway in Senegal's urban/suburban areas, with older women being more affected. Since several specific biocultural factors jointly contribute to this phenomenon, the study's findings suggest the need for local public health interventions that target women and which account for the anthropological specificities of the Senegalese population.

Nutrition Transition and Biocultural Determinants of Obesity among Cameroonian Migrants in Urban Cameroon and France.

Native of rural West Cameroon, the Bamiléké population is traditionally predisposed to obesity. Bamiléké who migrated to urban areas additionally experience the nutrition transition. We investigated the biocultural determinants of obesity in Bamiléké who migrated to urban Cameroon (Yaoundé), or urban France (Paris). We conducted qualitative interviews (n = 36; 18 men) and a quantitative survey (n = 627; 266 men) of adults using two-stage sampling strategy, to determine the association of dietary intake, physical activity and body weight norms with obesity of Bamiléké populations in these three socio-ecological areas (rural Cameroon: n = 258; urban Cameroon: n = 319; urban France: n = 50). The Bamiléké valued overweight and traditional energy-dense diets in rural and urban Cameroon. Physical activity levels were lower, consumption of processed energy-dense food was frequent and obesity levels higher in new migrants living in urban Cameroon and France. Female sex, age, duration of residence in urban areas, lower physical activity and valorisation of overweight were independently associated with obesity status. This work argues in favour of local and global health policies that account for the origin and the migration trajectories to prevent obesity in migrants.

Primate energy input and the evolutionary transition to energy-dense diets in humans.

Humans and other large-brained hominins have been proposed to increase energy turnover during their evolutionary history. Such increased energy turnover is plausible, given the evolution of energy-rich diets, but requires empirical confirmation. Framing human energetics in a phylogenetic context, our meta-analysis of 17 wild non-human primate species shows that daily metabolizable energy input follows an allometric relationship with body mass where the allometric exponent for mass is 0.75 ± 0.04, close to that reported for daily energy expenditure measured with doubly labelled water in primates. Human populations at subsistence level (n = 6) largely fall within the variation of primate species in the scaling of energy intake and therefore do not consume significantly more energy than predicted for a non-human primate of equivalent mass. By contrast, humans ingest a conspicuously lower mass of food (-64 ± 6%) compared with primates and maintain their energy intake relatively more constantly across the year. We conclude that our hominin hunter-gatherer ancestors did not increase their energy turnover beyond the allometric relationship characterizing all primate species. The reduction in digestive costs due to consumption of a lower mass of high-quality food, as well as stabilization of energy supply, may have been important evolutionary steps enabling encephalization in the absence of significantly raised energy intakes.

Development and validation of two food portion photograph books to assess dietary intake among adults and children in Central Africa.

Owing to nutritional transition in Cameroon, one in two adults is overweight and one in five is obese, and 8·1% of children are overweight and 2·1% are obese. Given this phenomenon, dietary intake assessment is needed to establish appropriate preventive nutrition-sensitive strategies. Our aim was to develop and test the validity of two food portion photograph books (FPPB) to be used as visual aids for adults and children taking part in a 24-h dietary recall. To design FPPB, interviews and focus group discussions were undertaken with women to obtain consensus on the local categorisation of foods. For each cooked and weighed food, three photographs of the average small, medium and large serving portion sizes were taken, and four intermediary portion sizes were calculated. To validate the FPPB, a sample of adults (361) and children (224) were asked, at meal times, to self-serve a food portion prepared in the household and the portion sizes were weighed; 24 h after the measurement, the same subjects were shown the appropriate FPPB and were asked to indicate the food and the portion they consumed. In adults, of the 821 portions tested, 77% were accurately estimated, whereas in children 74% of the 556 portions tested were accurately estimated. For both groups, the small- and medium-sized portions were frequently selected and accurately estimated (>70%). Our findings suggest that the adult and children's FPPB can be used in Cameroon to estimate food portion sizes, and thus nutritional intake in the frame of the 24-h dietary recall.

The relevance of the side-view in body image scales for public health: an example from two African populations.

BACKGROUND: Body size scales are a common method for diagnosing body image disturbances and assessing the cultural valorisation of stoutness, a phenomenon that plays a role in the development of overweight, especially among African populations. Traditionally, body size scales present a front view. In this study, we evaluated a complementary model of representing body shape: the side view of body outlines. In particular, we examined the association between the side-view and a set of bio-anthropometric indices in men and women. METHODS: To cover the inter-ethnic variability in the Niger-Congo area, we selected a balanced sex-ratio sample of 80 Cameroonians and 81 Senegalese. Individuals wearing close-fitting clothes were photographed from the front-and side-view, and measured following a bio-anthropometric protocol synthesizing body shape variation: Body Mass Index, percentage body fat, somatotype profile, waist circumference, waist-to-hip ratio, mean blood pressure and glycaemia. The shape of each front and side body outline was extracted and characterised by Normalized Elliptic Fourier Descriptors (NEFD). Finally, we assessed associations between NEFD and bio-anthropometric indices. RESULTS: Variation in the shape of both front and side body outlines was associated with all bio-anthropometrics for at least one sex-population combination. Overall, the side view best captured body shape variation related to changes in almost all bio-anthropometrics in both sexes and populations, with the exceptions of female mesomorphy, male blood pressure and glycaemia (in both sexes). We found that the details of the relationship between bio-anthropometrics and body shape differed between the two male populations, a finding that was reflected in side-views for all criteria, but not front-views. CONCLUSIONS: Variation in body shape assessed by several bio-anthropometrics related to health and nutritional status was larger for side than front body outlines. Integrating side views in body size scales would improve the accuracy of body size assessment and thus, the assessment of behaviours leading to overweight, as well as symptoms of body image disturbances, in Africa and potentially in other populations.

Development and Validation of the Body Size Scale for Assessing Body Weight Perception in African Populations.

BACKGROUND: The social valorisation of overweight in African populations could promote high-risk eating behaviours and therefore become a risk factor of obesity. However, existing scales to assess body image are usually not accurate enough to allow comparative studies of body weight perception in different African populations. This study aimed to develop and validate the Body Size Scale (BSS) to estimate African body weight perception. METHODS: Anthropometric measures of 80 Cameroonians and 81 Senegalese were used to evaluate three criteria of adiposity: body mass index (BMI), overall percentage of fat, and endomorphy (fat component of the somatotype). To develop the BSS, the participants were photographed in full face and profile positions. Models were selected for their representativeness of the wide variability in adiposity with a progressive increase along the scale. Then, for the validation protocol, participants self-administered the BSS to assess self-perceived current body size (CBS), desired body size (DBS) and provide a "body self-satisfaction index." This protocol included construct validity, test-retest reliability and convergent validity and was carried out with three independent samples of respectively 201, 103 and 1115 Cameroonians. RESULTS: The BSS comprises two sex-specific scales of photos of 9 models each, and ordered by increasing adiposity. Most participants were able to correctly order the BSS by increasing adiposity, using three different words to define body size. Test-retest reliability was consistent in estimating CBS, DBS and the "body self-satisfaction index." The CBS was highly correlated to the objective BMI, and two different indexes assessed with the BSS were consistent with declarations obtained in interviews. CONCLUSION: The BSS is the first scale with photos of real African models taken in both full face and profile and representing a wide and representative variability in adiposity. The validation protocol proved its reliability for estimating body weight perception in Africans.

Scaling of free-ranging primate energetics with body mass predicts low energy expenditure in humans.

Studies of how a mammal's daily energy expenditure scales with its body mass suggest that humans, whether Westerners, agro-pastoralists, or hunter-gatherers, all have much lower energy expenditures for their body mass than other mammals. However, non-human primates also differ from other mammals in several life history traits suggestive of low energy use. Judging by field metabolic rates of free-ranging strepsirhine and haplorhine primates with different lifestyle and body mass, estimated using doubly labeled water, primates have lower energy expenditure than other similar-sized eutherian mammals. Daily energy expenditure in humans fell along the regression line of non-human primates. The results suggest that thrifty energy use could be an ancient strategy of primates. Although physical activity is a major component of energy balance, our results suggest a need to revise the basis for establishing norms of energy expenditure in modern humans.

Positive selection of protective variants for type 2 diabetes from the Neolithic onward: a case study in Central Asia.

The high prevalence of type 2 diabetes and its uneven distribution among human populations is both a major public health concern and a puzzle in evolutionary biology. Why is this deleterious disease so common, while the associated genetic variants should be removed by natural selection? The 'thrifty genotype' hypothesis proposed that the causal genetic variants were advantageous and selected for during the majority of human evolution. It remains, however, unclear whether genetic data support this scenario. In this study, we characterized patterns of selection at 10 variants associated with type 2 diabetes, contrasting one herder and one farmer population from Central Asia. We aimed at identifying which alleles (risk or protective) are under selection, dating the timing of selective events, and investigating the effect of lifestyle on selective patterns. We did not find any evidence of selection on risk variants, as predicted by the thrifty genotype hypothesis. Instead, we identified clear signatures of selection on protective variants, in both populations, dating from the beginning of the Neolithic, which suggests that this major transition was accompanied by a selective advantage for non-thrifty variants. Combining our results with worldwide data further suggests that East Asia was particularly prone to such recent selection of protective haplotypes. As much effort has been devoted so far to searching for thrifty variants, we argue that more attention should be paid to the evolution of non-thrifty variants.

Is overweight in stunted preschool children in Cameroon related to reductions in fat oxidation, resting energy expenditure and physical activity?

BACKGROUND: Recent studies suggest that early modifications in metabolic pathways and behaviour, leading to energy conservation and reduced linear growth, could represent adaptations to nutritional constraints during foetal life and infancy. Impaired fat oxidation, low resting energy expenditure and reduced physical activity, resulting from these adaptations, could facilitate fat storage and development of overweight in growth-retarded children that consume more energy-dense food. This study aims at assessing whether: (1) dual-burden preschool children (simultaneously stunted and overweight) of Yaounde (Cameroon) have low birth-weight (indicator of foetal undernutrition) and reductions in fat oxidation, resting energy expenditure (REE) and physical activity, (2) fat oxidation, REE and physical activity are associated with foetal growth. METHODOLOGY/PRINCIPAL FINDINGS: 162 children (24-72 months) were considered: 22 stunted-overweight (SO), 40 stunted (S), 41 overweight (O), and 59 non stunted-non overweight (NSNO). Nutritional status and body composition were assessed using anthropometry and multifrequency bioimpedance analysis. Fasting respiratory quotient (RQ) and REE were measured by indirect calorimetry. Physical activity was determined using accelerometers, food questionnaires were used for diet assessment and birth-weight was noted. Mean RQs and REE (weight adjusted) did not differ between stunted children (SO and S) and non-stunted children (O and NSNO). SO and S children spent more time in sedentary activities than O children (p = 0.01 and p = 0.02, respectively) and less time in moderate-to-vigorous activities than NSNO children (p = 0.05 and p = 0.04, respectively). SO children's diet was less diverse (p = 0.01) with less animal products (p = 0.006). Multiple linear regressions model revealed that birth-weight is predictive of RQ (ß = 0.237, p<0.01, R(2) = 0.08). CONCLUSIONS/SIGNIFICANCE: This study showed that growth retardation in stunted-overweight children could be associated with postnatal nutritional deficiencies. Overweight in stunted children could be associated with reduced physical activity in the context of nutrition transition. High birth-weight was a predictor of reduced lipid oxidation, a risk factor of fat deposition.

Development of a new body image assessment scale in urban Cameroon: an anthropological approach.

OBJECTIVE: Develop and validate body image scales (BIS) presenting real human bodies adapted to the macroscopic phenotype of urban Cameroonian populations. DESIGN: Quantitative and qualitative analysis. SETTING: Yaoundé, capital city of Cameroon. PARTICIPANTS: Four samples with balanced sex-ratio: the first (n=16) aged 18 to 65 years (qualitative study), the second (n=30) aged 25 to 40 years (photo database), the third (n=47) and fourth (n=181), > or =18 years (validation study). MAIN OUTCOME MEASURE: Construct validity, test retest reliability, concurrent and convergent validity of BIS. RESULTS: Body image scales present six Cameroonians of each sex arranged according to main body mass index (BMI) categories: underweight (<18.5 kg/m2), normal (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), obesity class I (30-34.9 kg/m2), obesity class II (35-39.9 kg/m2), and obesity class III (> or =40 kg/m2). Test-retest reliability correlations for current body size (CBS), desired body size and current desirable discrepancy (body self-satisfaction index) on BIS were never below .90. Plus, for the concurrent validity, we observed a significant correlation (r=0.67, P<.01) between measured BMI and CBS. Finally, the convergent validity between BIS and a female African American silhouettes scale, for different dimensions of body size perceptions, is acceptable. CONCLUSIONS: Body image scales are adapted to the phenotypic characteristics of urban Cameroonian populations. They are reliable and valid to assess body size perceptions and culturally adapted to the Cameroonian context.

Lactase persistence in central Asia: phenotype, genotype, and evolution.

The aim of the present study is to document the evolution of the lactase persistence trait in Central Asia, a geographical area that is thought to have been a region of long-term pastoralism. Several ethnic groups co-exist in this area: Indo-Iranian speakers who are traditionally agriculturist (Tajik) and Turkic speakers who used to be nomadic herders (Kazakh, Karakalpak, Kyrgyz, Turkmen). It was recently demonstrated that horse milking practice existed in the Botai culture of Kazakhstan as early as 5,500 BP ( Outram et al. 2009 ). However, the frequency of the lactase persistence trait and its genetic basis in Central Asian populations remain largely unknown. We propose here the first genotype-phenotype study of lactase persistence in Central Asia based on 183 individuals, as well as the estimation of the time of expansion of the lactase-persistence associated polymorphism. Our results show a remarkable genetic-phenotypic correlation, with the causal polymorphism being the same than in Europe (-13.910C>T, rs4988235). The lactase persistence trait is at low frequency in these populations: between 25% and 32% in the Kazakh population (traditionally herders), according to phenotype used, and between 11% and 30% in the Tajiko-Uzbek population (agriculturalists). The difference in lactase persistence between populations, even if small, is significant when using individuals concordant for both excretion of breath hydrogen and the lactose tolerance blood glucose test phenotypes (P = 0.018, 25% for Kazakh vs. 11% for Tajiko-Uzbeks), and the difference in frequency of the -13.910*T allele is almost significant (P = 0.06, 30% for Kazakhs vs. 19% for Tajiko-Uzbeks). Using the surrounding haplotype, we estimate a date of expansion of the T allele around 6,000-12,000 yrs ago, which is consistent with archaeological records for the emergence of agropastoralism and pastoralism in Central Asia.

Total energy expenditure and body composition in two free-living sympatric lemurs.

BACKGROUND: Evolutionary theories that account for the unusual socio-ecological traits and life history features of group-living prosimians, compared with other primates, predict behavioral and physiological mechanisms to conserve energy. Low energy output and possible fattening mechanisms are expected, as either an adaptive response to drastic seasonal fluctuations of food supplies in Madagascar, or persisting traits from previously nocturnal hypometabolic ancestors. Free ranging ring-tailed lemurs (Lemur catta) and brown lemurs (Eulemur sp.) of southern Madagascar have different socio-ecological characteristics which allow a test of these theories: Both gregarious primates have a phytophagous diet but different circadian activity rhythms, degree of arboreality, social systems, and slightly different body size. METHODOLOGY AND RESULTS: Daily total energy expenditure and body composition were measured in the field with the doubly labeled water procedure. High body fat content was observed at the end of the rainy season, which supports the notion that individuals need to attain a sufficient physical condition prior to the long dry season. However, ring-tailed lemurs exhibited lower water flux rates and energy expenditure than brown lemurs after controlling for body mass differences. The difference was interpreted to reflect higher efficiency for coping with seasonally low quality foods and water scarcity. Daily energy expenditure of both species was much less than the field metabolic rates predicted by various scaling relationships found across mammals. DISCUSSION: We argue that low energy output in these species is mainly accounted for by low basal metabolic rate and reflects adaptation to harsh, unpredictable environments. The absence of observed sex differences in body weight, fat content, and daily energy expenditure converge with earlier investigations of physical activity levels in ring-tailed lemurs to suggest the absence of a relationship between energy constraints and the evolution of female dominance over males among lemurs. Nevertheless, additional seasonal data are required to provide a definitive conclusion.

Determinants of overweight associated with stunting in preschool children of Yaounde, Cameroon.

BACKGROUND: Nutrition transition in developing countries has been associated with higher prevalence of overweight. AIM: The study aimed to identify the factors associated with concurrent stunting and overweight in urban preschool children of Yaounde, Cameroon. SUBJECTS AND METHODS: 169 preschool children of both sexes were recruited according to their nutritional status: Stunted, overweight, stunted-overweight, and non-stunted-non-overweight. Factors associated with concurrent stunting and overweight were investigated through interviewer-administered questionnaires. A binary logistic regression model was used to determine the relation between nutritional statuses and associated factors. RESULTS: A low-income family and a low maternal educational level are independent risk factors for a child to be stunted-overweight [odds ratios (95% CI): 3.81 (13.32-1.08), 2.90 (7.82-1.07), respectively]. Mother under-evaluation of child's weight is a factor associated with stunting-overweight and overweight in children [odds ratios (95% CI): 3.42 (8.72-1.33), 6.52 (18.09-2.34), respectively]. Being overweight is also related to higher birth weight. Unlike stunted children, stunted-overweight children live with both their parents and have an older mother. Short maternal stature and mother's over-evaluation of her child's height are independent factors associated with stunting. CONCLUSION: Poor preschool children of Yaounde are facing concomitant stunting and overweight. More studies are needed to better assess the impact of maternal factors.

Dieta, actividad física y estado de nutrición en escolares tarahumaras, México / Diet, physical activity and nutrition state in tarahumara school children in Mexico

Objetivo: el objetivo del presente estudio fue describir y comparar la dieta, actividad física y el estado de nutrición en niños indígenas tarahumaras urbanos migrantes originarios del mismo municipio. Material y método: se realizó un estudio prospectivo, descriptivo, analítico y comparativo, de corte transversal, aplicado a 193 niños en tres grupos de ambos sexos de 6 a 12 años. Fueron aplicados recordatorios de 24 horas, pesos y actividad física con acelerometría, antropometría nutricional y mediciones bioquímicas. Resultados: se encontró retraso en crecimiento principalmente en el grupo tradicional. Existe una marcada anemia en el grupo migrante. Han sido observados casos de sobrepeso en niños semi-tradicionales. Se encontró un elevado porcentaje de sobrepeso y obesidad en niños urbanos. estas diferencias se explican más particularmente por variaciones en el patrón de consumo alimentario. Conclusión: se puede concluir que se observan cambios nutricionales en niños tarahumaras, que son más evidentes en zonas rurales, similares a muchas sociedades en transición económica. Este proceso de "desindigenización" o "mestizaje" de los patrones dietéticos tiene que ser analizado antes de implementar nuevas políticas a esta población indígena.

Objective: The objective of this study was to describe and compare the diet, physical activity and nutrition state in school age, indigenous Tarahumaras from three groups: traditional Tarahumara, semi-traditional Tarahumara and urban migrants originally from the same municipality. Materials and methods: This was a cross sectional, prospective, descriptive, analytic and comparative study, using 193 children in the three groups, both sexes, from 6 to 12 years old. We used 24 hours reminders, weights, physical activity with accelerometers, nutritional anthropometry and biochemical measurements. Results: We found growth delay mainly in the traditional group. There was marked anemia in the migrant group. We observed cases of overweight in children from the semi-traditional group, and an elevated percentage of obesity and overweight was found in the urban migrant group. These differences are explained in particular by variations in eating patterns. Conclusion: Nutritional changes were observed in Tarahumara children, and are more evident in rural zones, similar to many other societies in economic transition. This process of "deindigenization" or "mixing" of dietary patterns must be analyzed before implementing new policies targeted at this indigenous population.

Taste acuity of obese adolescents and changes in food neophobia and food preferences during a weight reduction session.

The relationship between taste acuity and food neophobia, food familiarity and liking has been studied in the context of a residential weight reduction session (WRS; mean duration: 10 months) in 39 obese adolescents. Taste acuity was assessed using recognition thresholds for sucrose, citric acid, sodium chloride and 6-n propylthiouracil (PROP) and supra-threshold perceived intensities for sucrose, sodium chloride and PROP. Food neophobia was assessed by using the food neophobia scale at the beginning and at the end of the WRS. At these time points we used also a food familiarity and liking questionnaire to assess changes in food familiarity and likes or dislikes for different food categories. Taste acuity appeared to mediate behavioural food-related changes during the WRS. High taste acuity was associated with limited reductions in food neophobia; less sensitive subjects showed greater increases in the acceptability of healthy foods, especially fruits and vegetables. Therefore, taste perception (and particularly PROP perception) appears to be a predictor of the magnitude of food-related behavioural change achieved during a WRS.

Taste perception in massively obese and in non-obese adolescents.

OBJECTIVE: The purpose is to determine whether taste functions are different in massively obese adolescents as compared with non-obese adolescents, and to what extent metabolic disorders may interfere with taste perception, as suggested by the results of recent animal studies. RESEARCH METHOD AND PROCEDURES: We compared taste sensitivity and hedonic responses of 39 adolescents with severe early onset obesity (mean BMI: 39.5; min-max: 30.9-51.6) and 48 non-obese adolescents (mean BMI: 21.0; min-max: 16.5-27.9) of both sexes. We measured recognition thresholds for fructose, sucrose, citric acid and sodium chloride. Supra-threshold perceived intensity and hedonic responses were assessed for solutions of sucrose and sodium chloride. In obese subjects, the occurrence of the metabolic syndrome was assessed by measuring blood pressure and, in blood samples, fasting glycemia and insulinemia, the concentration of triglycerides and HDL cholesterol. HOMA modelling was used to assess insulin resistance. RESULTS: Massively obese adolescents present a higher sensitivity to sucrose and sodium chloride than non-obese adolescents, with significantly lower recognition thresholds, and higher perceived intensities at supra-threshold levels for sucrose and salt. Hedonic responses are significantly lower for sodium chloride in the obese subjects. Among obese subjects, a significant positive correlation between taste responsiveness and the number of obesity-related metabolic disturbances is observed only in girls. CONCLUSION: Massively obese subjects have higher taste sensitivity than control subjects, especially for sucrose and salt. This can be explained, to some extent, by the influence of obesity-related metabolic disorders, which appears to be gender-specific.