Measurement of Ad Libitum Food Intake, Physical Activity, and Sedentary Time in Response to Overfeeding

Given the wide availability of highly palatable foods, overeating is common. Energy intake and metabolic responses to overfeeding may provide insights into weight gain prevention. We hypothesized a down-regulation in subsequent food intake and sedentary time, and up-regulation in non-exercise activity and core temperature in response to overfeeding in order to maintain body weight constant. In a monitored inpatient clinical research unit using a cross over study design, we investigated ad libitum energy intake (EI, using automated vending machines), core body temperature, and physical activity (using accelerometry) following a short term (3-day) weight maintaining (WM) vs overfeeding (OF) diet in healthy volunteers (n = 21, BMI, mean ± SD, 33.2±8.6 kg/m2, 73.6% male). During the ad libitum periods following the WM vs. OF diets, there was no significant difference in mean 3-d EI (4061±1084 vs. 3926±1284 kcal/day, p = 0.41), and there were also no differences either in core body temperature (37.0±0.2°C vs. 37.1±0.2°C, p = 0.75) or sedentary time (70.9±12.9 vs. 72.0±7.4%, p = 0.88). However, during OF (but not WM), sedentary time was positively associated with weight gain (r = 0.49, p = 0.05, adjusted for age, sex, and initial weight). In conclusion, short term overfeeding did not result in a decrease in subsequent ad libitum food intake or overall change in sedentary time although in secondary analysis sedentary time was associated with weight gain during OF. Beyond possible changes in sedentary time, there is minimal attempt to restore energy balance during or following short term overfeeding

FGF21 is a Hormonal Mediator of the Human "Thrifty" Metabolic Phenotype

Fibroblast growth factor 21 (FGF21) regulates energy expenditure (EE) and influences weight change after low-protein overfeeding in rodent models. The change in EE after low-protein overfeeding diet is a predictor of weight change in humans and a feature of the "thrifty" metabolic phenotype. However, there are no studies showing an association between circulating FGF21 and EE in humans. We assessed the changes in plasma FGF21 concentrations after 24 hours of seven dietary interventions with different macronutrient content while in a whole-room indirect calorimeter in 64 healthy subjects with normal glucose regulation. Plasma FGF21 concentration consistently increased by 3-fold only after the two low-protein (3%) overfeeding diets, one high in carbohydrate (75%) and the other high in fat (46%), with larger increases in FGF21 being associated with greater increases in 24-h EE. Subjects with smaller increases in FGF21 after the low-protein high-fat diet gained more weight after six months in free-living conditions. Therefore, the individual predisposition to weight gain over time can be assessed by 24-h overfeeding a low-protein diet and measurements of plasma FGF21 concentrations. Individuals with a blunted FGF21 response to a low-protein diet have a thrifty metabolism and are at risk for future weight gain

Bimodal distribution of RNA expression levels in human skeletal muscle tissue

<p>Abstract</p> <p>Background</p> <p>Many human diseases and phenotypes are related to RNA expression, levels of which are influenced by a wide spectrum of genetic and exposure-related factors. In a large genome-wide study of muscle tissue expression, we found that some genes exhibited a bimodal distribution of RNA expression, in contrast to what is usually assumed in studies of a single healthy tissue. As bimodality has classically been considered a hallmark of genetic control, we assessed the genome-wide prevalence, cause, and association of this phenomenon with diabetes-related phenotypes in skeletal muscle tissue from 225 healthy Pima Indians using exon array expression chips.</p> <p>Results</p> <p>Two independent batches of microarrays were used for bimodal assessment and comparison. Of the 17,881 genes analyzed, eight (<it>GSTM1, HLA-DRB1, ERAP2, HLA-DRB5, MAOA, ACTN3, NR4A2</it>, and <it>THNSL2</it>) were found to have bimodal expression replicated in the separate batch groups, while 24 other genes had evidence of bimodality in only one group. Some bimodally expressed genes had modest associations with pre-diabetic phenotypes, of note <it>ACTN3 </it>with insulin resistance. Most of the other bimodal genes have been reported to be involved with various other diseases and characteristics. Association of expression with <it>cis </it>genetic variation in a subset of 149 individuals found all but one of the confirmed bimodal genes and nearly half of all potential ones to be highly significant expression quantitative trait loci (eQTL). The rare prevalence of these bimodally expressed genes found after controlling for batch effects was much lower than the prevalence reported in other studies. Additional validation in data from separate muscle expression studies confirmed the low prevalence of bimodality we observed.</p> <p>Conclusions</p> <p>We conclude that the prevalence of bimodal gene expression is quite rare in healthy muscle tissue (<0.2%), and is much lower than limited reports from other studies. The major cause of these clearly bimodal expression patterns in homogeneous tissue appears to be <it>cis</it>-polymorphisms, indicating that such bimodal genes are, for the most part, eQTL. The high frequency of disease associations reported with these genes gives hope that this unique feature may identify or actually be an underlying factor responsible for disease development.</p

Beyond Zero-Sum Environmentalism

Environmental law and environmental protection are often portrayed as requiring trade offs: “jobs versus environment,” “markets versus regulation,” “enforcement versus incentives .” In the summer of 2016, members of the Environmental Law Collaborative gathered to consider how environmentalism and environmental regulation can advance beyond this framing to include new constituents and offer new pathways to tackle the many significant challenges ahead . Months later, the initial activities of the Trump Administration highlighted the use of zero-sum rhetoric, with the appointment of government officials and the issuance of executive orders that indeed seem to view environmental issues as in a zero-sum relationship with jobs or economic progress . In the essays below, the authors explore the meaning and the role of zero-sum environmentalism as a first step in moving beyond it

Environmental Law, Disrupted by COVID-19

For over a year, the COVID-19 pandemic and concerns about systemic racial injustice have highlighted the conflicts and opportunities currently faced by environmental law. Scientists uniformly predict that environmental degradation, notably climate change, will cause a rise in diseases, disproportionate suffering among communities already facing discrimination, and significant economic losses. In this Article, members of the Environmental Law Collaborative examine the legal system’s responses to these crises, with the goal of framing opportunities to reimagine environmental law. The Article is excerpted from their book Environmental Law, Disrupted, to be published by ELI Press later this year

Environmental Law Disrupted By COVID-19

For over a year, the COVID-19 pandemic and concerns about systemic racial injustice have highlighted the conflicts and opportunities currently faced by environmental law. Scientists uniformly predict that environmental degradation, notably climate change, will cause a rise in diseases, disproportionate suffering among communities already facing discrimination, and significant economic losses. In this Article, members of the Environmental Law Collaborative examine the legal system’s responses to these crises, with the goal of framing opportunities to reimagine environmental law. The Article is excerpted from their book Environmental Law, Disrupted, to be published by ELI Press later this year

Rethinking Sustainability to Meet the Climate Change Challenge

A group of environmental law professors formed the Environmental Law Collaborative with the goal of engaging environmental law scholars in the thorny issues of the day. The members of the Collaborative gathered in the summer of 2012 to produce an intensive and collective assessment of sustainability in the age of climate change. Their writings examine the process of adapting the principles and application of sustainability to the demands of climate change, including framing the term sustainability in climate change discussions; coordinating sustainable practices across disciplines such as law, economics, ethics, and the hard sciences; and conceptualizing the role of sustainability in formulating adaptation and resiliency strategies. Their work also contemplates the role of law and legal systems in crafting effective climate change adaptation strategies and considers feasible strategies in the context of specific examples