Fast-food consumption among 17-year-olds in the Birth to Twenty cohort

Objectives: Assessment of fast-food consumption in urban black adolescents.Design: The current research was a descriptive cross-sectional study.Setting: Subjects attending the Birth to Twenty (Bt20) research facility at the Chris Hani Baragwanath Hospital in Soweto, Johannesburg between September 2007 and May 2008 were enrolled.Subjects: 655 black subjects (51.1% females) were consecutively selected to participate from the larger cohort of Bt20.Outcome measures: Fast-food item consumption and frequency of  fast-food outlet visits were assessed by interviewer-administered questionnaire.Results: Over a 7-day assessment period, participants consumed 5 026 fast-food items, with the most popular food item being an item known colloquially as a ‘quarter’. There were no gender differences in terms of preferences. Mean fast-food intake was 8.1 (4.6) items and 7.2 (4.7) items per week for males and females respectively (ρ = 0.01). A typical ‘quarter’ consists of a quarter-loaf of white bread, chips, a slice of cheese and any number of delicatessen meats and sauces. A macronutrient comparison between a ‘quarter’ and three commercially available fast-food meals was undertaken, with the ‘quarter’ providing the most energy (5 970 kJ) and being the least expensive (mean cost = R9.16).Conclusion: The average estimated daily energy requirement for a 17-year-old is approximately 10 000 kJ, thus the ‘quarter’ may make a significant contribution to daily energy intake. Further research assessing the role of fast-foods in the provision of total energy and nutrient intakes in adolescents is require

Exploratory survey of informal vendor-sold fast food in rural South Africa

Background: South Africa is experiencing a dramatic increase in obesity in both urban and rural areas. It is important to understand access to food better and how this influences food choice in rural environments. This study aimed to explore the nature and availability of fast foods in rural South Africa.Method: Convenience sampling was used to procure fast food samples. The study was conducted in rural northeast South Africa in four villages, part of the South African Medical Research Council and University of the Witwatersrand-Agincourt Health and Socio-Demographic Surveillance System (HSDSS). The outcome measures were assessment of the availability of fast foods and their macronutrient composition.Results: This study highlights the availability of fast foods through informal community vendors. Of note is the limited variety of foods sold by informal vendors, of which a striking two thirds were either vetkoek or fried chips, which on average yielded 943–5 552 kJ and 11–64 g fat. Additionally, we found that rural vendors sold a local fast food item, the kota.Conclusion: Given that rural South Africa is undergoing rapid health, social, and nutrition transitions, this study signals the need for more comprehensive research to improve our understanding of the contributory role of fast food and its connection with both livelihoods and the burgeoning obesity epidemic in poorer rural areas. It is through better research and greater understanding that we can work with communities and local government to improve access to more nutrient-rich foods that are less energy dense.Keywords: fast food, vendor, rural, nutrition transition, South Afric

Early sexual debut: Voluntary or coerced? Evidence from longitudinal data in South Africa – the Birth to Twenty Plus study

Background: Early sexual debut, voluntary or coerced, increases risks to sexual and reproductive health. Sexual coercion is increasingly receiving attention as an important public health issue owing to its association with adverse health and social outcomes.Objective: To describe voluntary and coerced experience at sexual debut.Methods: A longitudinal perspective among 2 216 adolescents (1 149 females, 1 067 males) in a birth cohort study in South Africa, analysing data collected on six occasions between 11 and 18 years.Results: The median age of sexual debut was 16 years for females and 15 for males. Reported coerced sexual debut included children <11 years of age. Males reported earlier sexual debut, with both voluntary and coerced sexual experience, than females (p<0.0001). Sexual coercion at early sexual debut among both male and female adolescents occurred mostly through sexual intercourse with older adolescents and partners of the same age.Conclusion: The identified time periods and age groups need to be targeted for interventions to delay sexual debut and prevent sexual coercion among young people. More research is needed to understand underlying predisposing risk factors for sexual coercion at sexual debut, both early and not early

Under- and overnutrition and evidence of metabolic disease risk in rural black South African children and adolescents

Objectives: The objective was to determine the prevalence of under- and overnutrition, as well as evidence of metabolic disease risk in rural black South African children and adolescents.Design: A cross-sectional study was conducted.Setting: The setting was the Agincourt Health and Socio-demographic Surveillance System site, Mpumalanga province.Subjects: Six hundred children were randomly selected, of whom 588 were included in the analytical sample (mean age of 11.5 years, range of 7-15 years).Outcome measures: Outcome measures were anthropometric and blood pressure assessments, Tanner pubertal staging, as well as the determination of fasting serum lipid and glucose concentrations.Results: Using age and sex-specific World Health Organization 2007  growth references, the prevalence of stunting was determined to be 6.2% in the boys, and 2.7% in the girls, while 4.1% of the boys and 4.4% of the girls were underweight. Combined overweight and obesity prevalence was higher in the girls (13.5%) than in the boys (2.7%). Girls had significantly a higher body mass index and hip circumference than the boys in the early, mid and late pubertal stages. Pre-hypertension prevalence, using either systolic or diastolic blood pressure for sex, age and height, was 15% and 10% in the girls and boys, respectively. Furthermore, impaired fasting glucose (FG) (FG . 5.6 mmol/l) was detected in 5% of the children.  High-density lipoprotein cholesterol concentrations less than 1 mmol/l were observed in 0.7% of the boys and in 12% of the girls, which is indicative of cardiometabolic risk.Conclusion: Stunting levels were higher in the boys than in the girls in mid to late childhood in a rural setting in South Africa, while the girls had a higher prevalence of overweight and obesity than the boys.  Pre-hypertension prevalence in the boys and girls was high. Other  metabolic risk factors, i.e. impaired FG and lipids, were also seen in this population and were associated with adiposity. The study highlights the critical need for targeted health promotion interventions to optimise child health as part of a noncommunicable disease preventative strategy

Paediatric hypertension in South Africa: An underestimated problem calling for action.

Hypertension is a major global health problem and the most prominent risk factor for cardiovascular diseases, which disproportionately affect low- and middle-income countries (LMICs). According to a recent report from the Word Health Organization/Strategic Advisory Group of Experts (WHO-SAGE) group, almost half of the South African (SA) adult population is living with hypertension. Although the condition occurs less frequently in children than in adults, evidence now supports the concept that adult essential hypertension has its roots in childhood. A systematic review reports that the prevalence of hypertension in SA children ranges from 7.5% to 22.3%. One in five children aged 5 years is hypertensive (≥95th percentile for age, height and sex), and 60% of children with elevated blood pressure (BP) (>90th percentile for age, height and sex) maintain that status into early adulthood. In addition, there are distinct BP trajectories set early in childhood that are mainly driven by patterns of early life growth and socioeconomic environment. We seek to raise awareness of paediatric hypertension, its risk factors and its consequences, and highlight the importance of action, which can inform early detection and intervention strategies in the context of an increasing burden of cardiovascular disease in SA

Socio-economic predictors of stunting in preschool children – a population-based study from Johannesburg and Soweto

Background. Stunting continues to be a child public health concern in many African countries, including South Africa. This study uses data from the Birth to Twenty study, held in Johannesburg, to investigate a range of household-level socioeconomic and social support predictors of stunting in children aged less than 30 months.Design. Logistical regression models were constructed using aconceptual framework to investigate the association between early life measures of socio-economic status and stunting

Narratives of urban female adolescents in South Africa: dietary and physical activity practices in an obesogenic environment

Objectives: The objectives of this study were to investigate the narratives pertaining to dietary and physical activity practices by female adolescents in Soweto.Design: This was exploratory qualitative research, using duo interviews (pairs of best friends) (n = 29) from adolescent females.Setting: The setting was three urban high schools in the township of Soweto, South Africa.Subjects: Subjects were twenty-nine pairs of Grade 12 female adolescents predominantly, with a mean age of 18 years (15.3-21.6, standard deviation 1.1).Outcome measures: The outcome measure was body mass index, interpreted in relation to eating practices and exercise participation.Results: Locally prepared convenience foods were reported to replace home-prepared breakfast. The majority of participants did not prioritise eating breakfast at home, but purchased deep-fried dough balls (“fat” cakes) from vendors before school. Lunch boxes were also not commonly used as participants preferred to use spending money to purchase food from the school tuck shop. Kotas, “fat” cakes and snacks were popular lunch choices because of their affordability, convenience, peer influence and popularity. Respondents engaged in minimal active recreationalactivities. A lack of facilities and concerns about safety were barriers to activity.Conclusion: This study highlights the importance of investigating the immediate social context as a potential intervention point to improve the lifestyle of adolescents, to enable them to make the affordable and convenient choice, the healthier choice. Keywords: adolescent, eating, consumption, nutrition, physical activity, obesity, urban, South Afric

International gestational age-specific centiles for umbilical artery Doppler indices: a longitudinal prospective cohort study of the INTERGROWTH-21st Project.

BACKGROUND: Reference values for umbilical artery Doppler indices are used clinically to assess fetal well-being. However, many studies that have produced reference charts have important methodologic limitations, and these result in significant heterogeneity of reported reference ranges. OBJECTIVES: To produce international gestational age-specific centiles for umbilical artery Doppler indices based on longitudinal data and the same rigorous methodology used in the original Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project. STUDY DESIGN: In Phase II of the INTERGROWTH-21st Project (the INTERBIO-21st Study), we prospectively continued enrolling pregnant women according to the same protocol from 3 of the original populations in Pelotas (Brazil), Nairobi (Kenya), and Oxford (United Kingdom) that had participated in the Fetal Growth Longitudinal Study. Women with a singleton pregnancy were recruited at <14 weeks' gestation, confirmed by ultrasound measurement of crown-rump length, and then underwent standardized ultrasound every 5±1 weeks until delivery. From 22 weeks of gestation umbilical artery indices (pulsatility index, resistance index, and systolic/diastolic ratio) were measured in a blinded fashion, using identical equipment and a rigorously standardized protocol. Newborn size at birth was assessed using the international INTERGROWTH-21st Standards, and infants had detailed assessment of growth, nutrition, morbidity, and motor development at 1 and 2 years of age. The appropriateness of pooling data from the 3 study sites was assessed using variance component analysis and standardized site differences. Umbilical artery indices were modeled as functions of the gestational age using an exponential, normal distribution with second-degree fractional polynomial smoothing; goodness of fit for the overall models was assessed. RESULTS: Of the women enrolled at the 3 sites, 1629 were eligible for this study; 431 (27%) met the entry criteria for the construction of normative centiles, similar to the proportion seen in the original fetal growth longitudinal study. They contributed a total of 1243 Doppler measures to the analysis; 74% had 3 measures or more. The healthy low-risk status of the population was confirmed by the low rates of preterm birth (4.9%) and preeclampsia (0.7%). There were no neonatal deaths and satisfactory growth, health, and motor development of the infants at 1 and 2 years of age were documented. Only a very small proportion (2.8%-6.5%) of the variance of Doppler indices was due to between-site differences; in addition, standardized site difference estimates were marginally outside this threshold in only 1 of 27 comparisons, and this supported the decision to pool data from the 3 study sites. All 3 Doppler indices decreased with advancing gestational age. The 3rd, 5th 10th, 50th, 90th, 95th, and 97th centiles according to gestational age for each of the 3 indices are provided, as well as equations to allow calculation of any value as a centile and z scores. The mean pulsatility index according to gestational age = 1.02944 + 77.7456*(gestational age)-2 - 0.000004455*gestational age3. CONCLUSION: We present here international gestational age-specific normative centiles for umbilical artery Doppler indices produced by studying healthy, low-risk pregnant women living in environments with minimal constraints on fetal growth. The centiles complement the existing INTERGROWTH-21st Standards for assessment of fetal well-being

Even transient rapid infancy weight gain is associated with higher BMI in young adults and earlier menarche.

BACKGROUND: Early postnatal rapid 'catch-up' weight gain has been consistently associated with subsequent higher obesity risk and earlier pubertal development. In many low- and middle-income countries, infancy catch-up weight gain is transient and often followed by growth faltering. We explored the hypothesis that even transient catch-up weight gain during infancy is associated with later obesity risk and earlier puberty. METHODS: A total of 2352 (1151 male, 1201 female) black South African children in the birth to twenty prospective birth cohort study (Johannesburg-Soweto) underwent serial measurements of body size and composition from birth to 18 years of age. At the age of 18 years, whole-body fat mass and fat-free mass were determined using dual-energy X-ray absorptiometry. Pubertal development was assessed by the research team between ages 9 and 10 years, and it was recorded annually from the age of 11 years using a validated self-assessment protocol. RESULTS: Catch-up weight gain from birth to the age of 1 year, despite being followed by growth faltering between ages 1 and 2 years, was associated with greater mid-upper arm circumference (P=0.04) and skinfold thickness (P=0.048) at 8 years of age, and with higher weight (P<0.001) and body mass index (P=0.001) at 18 years of age after adjustment for sex, age, smoking during pregnancy, birth order, gestational age, formula-milk feeding and household socio-economic status. Infancy catch-up weight gain was also associated with younger age at menarche in girls (P<0.001). This association persisted after adjustment for smoking during pregnancy, birth order, gestational age, formula-milk feeding and household socio-economic status (P=0.005). CONCLUSION: Transient catch-up weight gain from birth to the age of 1 year among children born in a low-income area of South Africa was associated with earlier menarche and greater adiposity in early adulthood. This observation suggests that modifiable determinants of rapid infancy weight gain may be targeted in order to prevent later obesity and consequences of earlier puberty in girls.We are grateful to all study participants, their families and research assistants. Birth to twenty has been supported by The Wellcome Trust, Human Sciences Research Council, Medical Research Council, University of the Witwatersrand, the South African-Netherlands Programme on Alternative Development and the Anglo American Chairman’s Fund.This is the author accepted manuscript. The final version is available via NPG at http://www.nature.com/ijo/journal/vaop/ncurrent/full/ijo201525a.html