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There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decreasing GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages.

Obesity is caused by a prolonged positive energy balance1,2. Whether reduced energy expenditure stemming from reduced activity levels contributes is debated3,4. Here we show that in both sexes, total energy expenditure (TEE) adjusted for body composition and age declined since the late 1980s, while adjusted activity energy expenditure increased over time. We use the International Atomic Energy Agency Doubly Labelled Water database on energy expenditure of adults in the United States and Europe (n = 4,799) to explore patterns in total (TEE: n = 4,799), basal (BEE: n = 1,432) and physical activity energy expenditure (n = 1,432) over time. In males, adjusted BEE decreased significantly, but in females this did not reach significance. A larger dataset of basal metabolic rate (equivalent to BEE) measurements of 9,912 adults across 163 studies spanning 100 years replicates the decline in BEE in both sexes. We conclude that increasing obesity in the United States/Europe has probably not been fuelled by reduced physical activity leading to lowered TEE. We identify here a decline in adjusted BEE as a previously unrecognized factor.

Background/Objectives Young Indian adults are at greater risk of overweight/obesity due to their high energy intake and sedentary lifestyle. Their energy requirement (ER) is based on their total energy expenditure (TEE) estimated from factorial method, which possibly overestimates their basal metabolic rate (BMR) and physical activity level (PAL). This study aimed to compare the accurately measured TEE with ER in young adults. Secondarily, to compare measured with predicted BMR and guideline PAL with that obtained from questionnaire and step counts. Subjects/Methods TEE was measured in 19 male adults (18-30 years), using the doubly labeled water technique, over 14 days. Indirect calorimetry was used to measure BMR, while the PAL was estimated by (a) the ratio of measured TEE and BMR, (b) step counts over 7 days measured using tri-axial accelerometers and (c) a physical activity questionnaire (PAQ). Results The measured TEE (9.11 [plus or minus] 1.30 MJ/d) was significantly lower than the ER using either the Indian (15.2%) or the FAO/WHO/UNU (11.9%, both p < 0.01) recommendations. The measured BMR (6.90 [plus or minus] 0.65 MJ/d) was significantly lower than that predicted using the FAO/WHO/UNU equation (6.5%, p < 0.01) but not for the Indian equation. The estimated PAL from measured TEE and BMR (1.35 [plus or minus] 0.18), and from accelerometers (1.33 [plus or minus] 0.11) was significantly lower than PAL obtained from PAQ (1.53 [plus or minus] 0.17) or the guideline of 1.53 for Indians. Conclusions The predicted BMR and PAL guideline value was higher than that measured in young Indian adults, resulting in a ~13% lower measured TEE. This emphasizes the need to revisit the guidelines for predicting ER for this population., Author(s): Srishti Sinha [sup.1] , Anura V. Kurpad [sup.1] [sup.2] , Rebecca Kuriyan [sup.1] Author Affiliations: (1) Division of Nutrition, St. John's Research Institute, A recognized research center of University [...]

Plastic pollution is ubiquitous in terrestrial and aquatic ecosystems. Plastic waste exposed to the environment creates problems and is of significant concern for all life forms. Plastic production and accumulation in the natural environment are occurring at an unprecedented rate due to indiscriminate use, inadequate recycling, and deposits in landfills. In 2019, the global production of plastic was at 370 million tons, with only 9% of it being recycled, 12% being incinerated, and the remaining left in the environment or landfills. The leakage of plastic wastes into terrestrial and aquatic ecosystems is occurring at an unprecedented rate. The management of plastic waste is a challenging problem for researchers, policymakers, citizens, and other stakeholders. Therefore, here, we summarize the current understanding and concerns of plastics pollution (microplastics or nanoplastics) on natural ecosystems. The overall goal of this review is to provide background assessment on the adverse effects of plastic pollution on natural ecosystems; interlink the management of plastic pollution with sustainable development goals; address the policy initiatives under transdisciplinary approaches through life cycle assessment, circular economy, and sustainability; identify the knowledge gaps; and provide current policy recommendations. Plastic waste management through community involvement and socio-economic inputs in different countries are presented and discussed. Plastic ban policies and public awareness are likely the major mitigation interventions. The need for life cycle assessment and circularity to assess the potential environmental impacts and resources used throughout a plastic product's life span is emphasized. Innovations are needed to reduce, reuse, recycle, and recover plastics and find eco-friendly replacements for plastics. Empowering and educating communities and citizens to act collectively to minimize plastic pollution and use alternative options for plastics must be promoted and enforced. Plastic pollution is a global concern that must be addressed collectively with the utmost priority. [ABSTRACT FROM AUTHOR]