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Most countries worldwide, especially low- and middle-income countries (LMICs), are facing an increasing prevalence of fast-food consumption and multiple burdens of malnutrition among young adolescents. To compare the prevalence of fast-food consumption among young adolescents in LMICs. We used data from the most recent Global School-Based Student Health Survey (2009–2015), which had been collected using a standardized questionnaire. The weighted prevalence and 95% confidential intervals of fast-food consumption were calculated overall and in subgroups stratified by age, sex, and nutritional status. The pooled overall and regional estimates were obtained using a random-effects model. Heterogeneity was assessed using the I2 statistic. The associated risk factors for fast-food consumption were explored using logistic regression analysis. Our study comprised 153,496 young adolescents (46.90% boys) from 54 LMICs. Overall, approximately 55.2% (51.3–59.1%) of the adolescents consumed fast food at least 1 day per week, and 10.3% (8.3–12.4%) did so 4–7 days per week. The prevalence of fast-food consumption 4–7 days per week was lowest in the Americas (8.3%; 6.7–9.9%) and highest in Southeast Asia (17.7%; 2.3–33.2%). At a country level, the prevalence was lowest in Pakistan (1.5%; 1.0–2.0%) and highest in Thailand (43.3%; 40.4–46.1%). Furthermore, in subgroups stratified by nutritional status, the prevalence was lowest in the obesity group (6.6%; 4.5–8.7%). Factors such as age, sex, BMI, food insecurity, fruit consumption, vegetable consumption, soft-drink consumption, smoking, physical activity level, and sedentary behavior level were found to be correlated with fast-food consumption. The identified high prevalence of fast-food consumption among young adolescents in LMICs indicates the urgent need to prioritize the implementation of healthy-diet promotion programs to improve adolescent health in these countries. [ABSTRACT FROM AUTHOR]

To identify environmental causes for past changes in vegetation in subtropical East Asia, we present carbon isotope compositions of plant-wax n -alkanes and provide estimates of the C 4 -plant contribution across the past four glacial terminations and interglacials, based on cores recovered from the northern South China Sea. Our results show a comparable C 4 -plant contribution between the Last Glacial Maximum (LGM) and the Holocene. An increase of the C 4 -plant contribution by 15–20% is found for Terminations IV, II and I relative to subsequent interglacial peaks, coeval with an expansion of Cyperaceae and Poaceae. In contrast, Termination V reveals a lower C 4 -plant contribution than Marine Isotope Stage (MIS) 11c. The data exhibit a long-term trend, with a stepwise increase of the C 4 -plant contribution across interglacials MIS 11c, 9e, 7e and 1. We suggest that no substantial changes in humidity levels over glacial-interglacial cycles occurred facilitating a similar C 3 /C 4 -plant ratio for the LGM and the Holocene. Instead, deglacial sea-level rises caused an extensive development of floodplains and wetlands on the exposed continental shelf, providing habitats for the spread of C 4 sedges and grasses. The progressive subsidence of Chinese coastal areas and the broadening of the continental shelf over the late Quaternary explains the nearly absence of C 4 plant occurrence during Termination V and a gradual increase of the C 4 -plant contribution across interglacial peaks. Taken together, changes in coastal environments should be considered when interpreting marine-based vegetation reconstructions from subtropical Asia. • High-resolution plant-wax δ13C records for past four interglacials and glacial terminations. • C 4 -plant expansions on the exposed continent shelf occurred over glacial terminations. • Changes in coastal environments rather than climate cause alterations of vegetation composition. • Progressive broadening of the continental shelfs explains long-term vegetation changes. [ABSTRACT FROM AUTHOR]