Toward healthy and sustainable diets for the 21st century: Importance of sociocultural and economic considerations.

Four years after the EAT-Lancet landmark report, worldwide movements call for action to reorient food systems to healthy diets that respect planetary boundaries. Since dietary habits are inherently local and personal, any shift toward healthy and sustainable diets going against this identity will have an uphill road. Therefore, research should address the tension between the local and global nature of the biophysical (health, environment) and social dimensions (culture, economy). Advancing the food system transformation to healthy, sustainable diets transcends the personal control of engaging consumers. The challenge for science is to scale-up, to become more interdisciplinary, and to engage with policymakers and food system actors. This will provide the evidential basis to shift from the current narrative of price, convenience, and taste to one of health, sustainability, and equity. The breaches of planetary boundaries and the environmental and health costs of the food system can no longer be considered externalities. However, conflicting interests and traditions frustrate effective changes in the human-made food system. Public and private stakeholders must embrace social inclusiveness and include the role and accountability of all food system actors from the microlevel to the macrolevel. To achieve this food transformation, a new "social contract," led by governments, is needed to redefine the economic and regulatory power balance between consumers and (inter)national food system actors.

Toward Systems Models for Obesity Prevention: A Big Role for Big Data.

The relation among the various causal factors of obesity is not well understood, and there remains a lack of viable data to advance integrated, systems models of its etiology. The collection of big data has begun to allow the exploration of causal associations between behavior, built environment, and obesity-relevant health outcomes. Here, the traditional epidemiologic and emerging big data approaches used in obesity research are compared, describing the research questions, needs, and outcomes of 3 broad research domains: eating behavior, social food environments, and the built environment. Taking tangible steps at the intersection of these domains, the recent European Union project "BigO: Big data against childhood obesity" used a mobile health tool to link objective measurements of health, physical activity, and the built environment. BigO provided learning on the limitations of big data, such as privacy concerns, study sampling, and the balancing of epidemiologic domain expertise with the required technical expertise. Adopting big data approaches will facilitate the exploitation of data concerning obesity-relevant behaviors of a greater variety, which are also processed at speed, facilitated by mobile-based data collection and monitoring systems, citizen science, and artificial intelligence. These approaches will allow the field to expand from causal inference to more complex, systems-level predictive models, stimulating ambitious and effective policy interventions.

Is nutrition science ready for the twenty-first century? Moving towards transdisciplinary impacts in a changing world.

Malnutrition in an obese world was the fitting title of the 13th Federation of European Nutrition Societies (FENS) conference held in October 2019. Many individuals do not eat a healthy, well-balanced diet, and this is now understood to be a major driver of increased disease risk and illness. Moreover, both our current eating patterns and the food system as a whole are environmentally unsustainable, threatening the planetary systems we depend on for survival. As we attempt to feed a growing global population, food systems will increasingly be confronted with their environmental impacts, with the added challenge of climate change-induced threats to food production. As we move into the third decade of the twenty-first century, these challenges demand that the nutrition research community reconsider its scope, concepts, methods, and societal role. At a pre-meeting workshop held at the FENS conference, over 70 researchers active in the field explored ways to advance the discipline's capacity to address cross-cutting issues of personal, public and planetary health. Using the world cafe method, four themed discussion tables explored (a) the breadth of scientific domains needed to meet the current challenges, (b) the nature and definition of the shifting concepts in nutrition sciences, (c) the next-generation methods required and (d) communication and organisational challenges and opportunities. As a follow-up to earlier work [1], here we report the highlights of the discussions, and propose the next steps to advance responsible research and innovation in the domain of nutritional science.

Melanopsin Retinal Ganglion Cells Regulate Cone Photoreceptor Lamination in the Mouse Retina.

Newborn neurons follow molecular cues to reach their final destination, but whether early life experience influences lamination remains largely unexplored. As light is among the first stimuli to reach the developing nervous system via intrinsically photosensitive retinal ganglion cells (ipRGCs), we asked whether ipRGCs could affect lamination in the developing mouse retina. We show here that ablation of ipRGCs causes cone photoreceptors to mislocalize at different apicobasal positions in the retina. This effect is partly mediated by light-evoked activity in ipRGCs, as dark rearing or silencing of ipRGCs leads a subset of cones to mislocalize. Furthermore, ablation of ipRGCs alters the cone transcriptome and decreases expression of the dopamine receptor D4, while injection of L-DOPA or D4 receptor agonist rescues the displaced cone phenotype observed in dark-reared animals. These results show that early light-mediated activity in ipRGCs influences neuronal lamination and identify ipRGC-elicited dopamine release as a mechanism influencing cone position.

N-type Ca2+ channels carry the largest current: implications for nanodomains and transmitter release.

Presynaptic terminals favor intermediate-conductance Ca(V)2.2 (N type) over high-conductance Ca(V)1 (L type) channels for single-channel, Ca(2+) nanodomain-triggered synaptic vesicle fusion. However, the standard Ca(V)1>Ca(V)2>Ca(V)3 conductance hierarchy is based on recordings using nonphysiological divalent ion concentrations. We found that, with physiological Ca(2+) gradients, the hierarchy was Ca(V)2.2>Ca(V)1>Ca(V)3. Mathematical modeling predicts that the Ca(V)2.2 Ca(2+) nanodomain, which is ∼25% more extensive than that generated by Ca(V)1, can activate a calcium-fusion sensor located on the proximal face of the synaptic vesicle.