Diminishing benefits of urban living for children and adolescents’ growth and development

AbstractOptimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was &lt;1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.</jats:p

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI 2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining https://researchonline.ljmu.ac.uk/images/research_banner_face_lab_290.jpgunderweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity

Effect of nitrogen doses on disease severity and watermelon yield Influência de doses de nitrogênio na severidade de doenças e na produtividade da melancia

Nitrogen fertilization is an important step for watermelon (Citrullus lanatus) production due to its influence over yield, fruit quality, and disease severity. Currently, the gummy stem blight (Didymella bryoniae) and the downy mildew (Pseudoperonospora cubensis) can be taken as the most important watermelon diseases, since they impose severe impairment to the crop. Furthermore, studies focusing on plant responses to nitrogen fertilization regarding fruit yield and quality, and disease resistance are rare. Hence, the present study aimed at evaluating the effect of nitrogen doses on fruit yield and quality, and on disease prevalence in watermelon. Two experiments were carried out at the Universidade Federal de Tocantins, employing sprinkler irrigation, in an area previously used to grow watermelon. The experimental design was blocks at random, with five treatments (N doses, applied twice as side-dressing, in kg ha-1, as follows: T1= control treatment without N, T2= 20, T3= 40, T4= 80, and T5= 120), and four replications. Urea (45% N) was used as the N source. In the first assay, the highest fruit yield and average weight were observed when 40 kg ha-1 of N were applied. The highest severity of the gummy stem blight was observed when the highest nitrogen doses were applied (80 and 120 kg ha-1). In the second assay, the highest severity levels of the gummy stem blight, as well as of mildew, were observed again when N doses were the highest (80 and 120 kg ha-1). The lowest severity levels for both diseases were observed in the control treatment.<br>A adubação nitrogenada é importante para a cultura da melancia (Citrullus lanatus) por afetar diretamente a produtividade, a qualidade dos frutos e a severidade de doenças. Atualmente, o crestamento gomoso (Didymella bryoniae) e o míldio (Pseudoperonospora cubensis) podem ser consideradas as doenças mais importantes da melancia devido aos prejuízos que podem causar na lavoura. Estudos envolvendo a aplicação de doses de nitrogênio e seus efeitos na produtividade, qualidade de frutos e manifestação de doenças são escassos. Desta forma, o presente trabalho teve como objetivo avaliar diferentes doses de nitrogênio e seus efeitos na produtividade, características dos frutos e na prevalência de doenças da melancieira. Foram conduzidos dois ensaios na Universidade Federal do Tocantins, sob irrigação por aspersão, em área anteriormente cultivada com melancia. Foi utilizado o delineamento experimental de blocos ao acaso, com cinco tratamentos (doses de nitrogênio, aplicados em duas vezes em cobertura, em kg ha-1, sendo T1= testemunha sem nitrogênio em cobertura, T2= 20, T3= 40, T4= 80 e T5= 120) e quatro repetições. A uréia foi utilizada como fonte de nitrogênio (45% de N). No ensaio I, verificou-se maior produtividade e maior peso médio de frutos no tratamento que recebeu 40 kg ha-1. Níveis mais altos de severidade do crestamento gomoso foram verificados nos tratamentos que receberam maiores dosagens de nitrogênio (80 e 120 kg). No ensaio II, nos tratamentos com 80 e 120 kg ha de N foram observados os níveis mais altos de míldio e crestamento gomoso. Menores níveis dessas doenças foram verificados no tratamento testemunha

Interferência de plantas daninhas no cultivo da melancia Weeds interference periods in watermelon crop

A cultura da melancia é uma atividade explorada regionalmente, sendo uma das mais importantes fontes de renda familiar de pequenos municípios do médio Paranapanema, onde mudanças significativas no processo produtivo são atualmente constatadas, passando de mão-de-obra intensiva para uso de tecnologias promissoras, como é o caso do manejo de plantas daninhas. Um experimento foi conduzido no município de Oscar Bressani (SP), em área de produção comercial, com objetivo de estudar a interferência de plantas daninhas, no cultivo da melancia, na safra 2002/2003. O delineamento experimental utilizado foi de blocos ao acaso com dez tratamentos e quatro repetições, representadas por parcelas com área útil de 18 m², contendo quatro plantas de melancia e infestação prevalecente das espécies Sidaspp, Brachiaria humidicola, Commelina benghalensise Portulaca oleracea. A infestação das plantas daninhas foi estimada através de amostragens aleatórias das parcelas utilizando-se quadro vazado de ferro com 0,5 m de lado. Os tratamentos constaram de testemunhas capinadas e sem capina e diferentes épocas de controle da infestação, de forma que a cultura foi mantida na presença ou ausência das plantas daninhas até 7; 14; 28; 56 e 63 dias após a sua emergência (DAE). A ocorrência do período inicial de convivência possível maior que o período final estabeleceu o Período Crítico de Prevenção da Interferência do 9º ao 13º dias (PCPI= 9-13 DAE). A redução média da produtividade em função da interferência das plantas daninhas durante todo o ciclo da melancia foi de 41,4%. As características diâmetro e espessura da casca dos frutos também foram influenciadas pela convivência com a infestação durante todo o ciclo com decréscimos, de 7,9% e 23,3%, respectivamente, em média, ao contrário do comprimento e diâmetro de ramas e do ºBrix da polpa dos frutos, onde não foram constatadas diferenças significativas.<br>Water melon crop is an agricultural activity explored regionally, representing one of the most important sources of family income in small cities of the Médio Paranapanema, São Paulo State, Brazil, where nowadays, significant changes in the yield process are verified, changing from intensive labor to the use of promising technologies, as weed management, for instance. An experiment was carried out at Oscar Bressane municipal district, São Paulo State, Brazil, to study the weed interference on watermelon cultivation, in 2002/2003. Statistical procedure was based on randomized blocks with ten treatments and four replications, represented by plots with useful area of 18 m², containing four water melon plants and infestation of Sidaspp, Brachiaria humidicola, Commelina benghalensisand Portulaca oleraceaspecies. Weed infestation was estimated through randomized samples from the plots, using an iron drained square with 0,5 m sides. Treatments consisted of checks with and without hand weeded and different periods of weeds control, so that, crop was sustained in weeds presence or absence up to 7; 14; 28; 56 and 63 days after emergency (DAE). Initial period occurrence of possible coexistence greater than the final period established the Critical Period of Interference Prevention from the 9th to the 13th days (CPIP = 9-13 DAE). The reduction in yield due to the weed interference during all water melon crop cycle was about 41,4%. The diameter and thickness of fruits peel were also influenced by the coexistence with weed infestation during all the crop cycle, with decreases of 7,9% and 23,3%, respectively, against the characteristics length and diameter of branch and ºBrix of fruits pulp, when significant differences were not observed