Upper Paleolithic Figurines Showing Women with Obesity may Represent Survival Symbols of Climatic Change

Evidence from personal ornaments suggest nine distinct cultural groups between 34,000 and 24,000 years ago in Europe

Mechanisms governing the relationship between genetic and cultural evolution are the subject of debate, data analysis and modelling efforts. Here we present a new georeferenced dataset of personal ornaments worn by European hunter-gatherers during the so-called Gravettian technocomplex (34,000-24,000 years ago), analyse it with multivariate and geospatial statistics, model the impact of distance on cultural diversity and contrast the outcome of our analyses with up-to-date palaeogenetic data. We demonstrate that Gravettian ornament variability cannot be explained solely by isolation-by-distance. Analysis of Gravettian ornaments identified nine geographically discrete cultural entities across Europe. While broadly in agreement with palaeogenetic data, our results highlight a more complex pattern, with cultural entities located in areas not yet sampled by palaeogenetics and distinctive entities in regions inhabited by populations of similar genetic ancestry. Integrating personal ornament and biological data from other Palaeolithic cultures will elucidate the complex narrative of population dynamics of Upper Palaeolithic Europe.

Models of body weight and fatness regulation

Body weight and fatness appear to be regulated phenomena. Several different theoretical models are available to capture the essence of this idea. These include the set-point, dynamic equilibrium, adiposity force, control theory-settling point, Hall-Guo, operation point and dual intervention point (DIP) models. The set-point model posits a single reference point around which levels of fat are regulated. The dynamic equilibrium model suggests that the apparent regulation of body fat around a reference point is an illusion owing to the necessary impacts of weight change on energy expenditure. Control theory focuses on the importance of feedback gain and suggests set-point and dynamic equilibrium are ends of a continuum of feedback gain. Control theory models have also been called 'settling point' models. The Hall-Guo, operation point and DIP models also bring together the set-point and dynamic equilibrium ideas into a single framework. The DIP proposes a zone of indifference where dynamic equilibrium 'regulation' predominates, bounded by upper and lower intervention points beyond which physiological mechanisms are activated. The drifty gene hypothesis is an idea explaining where this individual variation in the upper intervention point might come from. We conclude that further experiments to test between the models are sorely required. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

The fructose survival hypothesis for obesity

The fructose survival hypothesis proposes that obesity and metabolic disorders may have developed from over-stimulation of an evolutionary-based biologic response (survival switch) that aims to protect animals in advance of crisis. The response is characterized by hunger, thirst, foraging, weight gain, fat accumulation, insulin resistance, systemic inflammation and increased blood pressure. The process is initiated by the ingestion of fructose or by stimulating endogenous fructose production via the polyol pathway. Unlike other nutrients, fructose reduces the active energy (adenosine triphosphate) in the cell, while blocking its regeneration from fat stores. This is mediated by intracellular uric acid, mitochondrial oxidative stress, the inhibition of AMP kinase and stimulation of vasopressin. Mitochondrial oxidative phosphorylation is suppressed, and glycolysis stimulated. While this response is aimed to be modest and short-lived, the response in humans is exaggerated due to gain of 'thrifty genes' coupled with a western diet rich in foods that contain or generate fructose. We propose excessive fructose metabolism not only explains obesity but the epidemics of diabetes, hypertension, non-alcoholic fatty liver disease, obesity-associated cancers, vascular and Alzheimer's dementia, and even ageing. Moreover, the hypothesis unites current hypotheses on obesity. Reducing activation and/or blocking this pathway and stimulating mitochondrial regeneration may benefit health-span. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.

Obesity and the risk of cardiometabolic diseases

The prevalence of obesity has reached pandemic proportions, and now approximately 25% of adults in Westernized countries have obesity. Recognized as a major health concern, obesity is associated with multiple comorbidities, particularly cardiometabolic disorders. In this Review, we present obesity as an evolutionarily novel condition, summarize the epidemiological evidence on its detrimental cardiometabolic consequences and discuss the major mechanisms involved in the association between obesity and the risk of cardiometabolic diseases. We also examine the role of potential moderators of this association, with evidence for and against the so-called 'metabolically healthy obesity phenotype', the 'fatness but fitness' paradox or the 'obesity paradox'. Although maintenance of optimal cardiometabolic status should be a primary goal in individuals with obesity, losing body weight and, particularly, excess visceral adiposity seems to be necessary to minimize the risk of cardiometabolic diseases.

Weight Bias in Reproductive Medicine: A Curiously Unexplored Frontier

Obesity has been associated with a multitude of medical comorbidities, infertility, and adverse obstetric outcomes. Weight stigma and weight bias pervade not only the medical field but also education, employment, and activities of daily living. The experience of weight stigma has been shown to adversely impact not only the mental health of individuals with overweight or obesity but also worsen obesogenic behaviors, and medical comorbidities. This review frames the rise of weight stigma and weight bias within the context of the "obesity epidemic" and explores its associations with infertility and decreased access to health care and its subsequent impact on the lives of individuals. Furthermore, it explores the concepts of intrinsic and extrinsic weight stigma/bias and highlights the need for further examination and research into the impact of these factors on access to reproductive medicine and subsequent outcomes.

The unexpected role of the STING protein in lipid metabolism

Detection of cytosolic pathological nucleic acids is a key step for the initiation of innate immune responses. In the past decade, the stimulator of interferon genes (STING) adaptor protein has emerged as a central platform enabling the activation of inflammatory responses in the presence of cytosolic DNAs. This has prompted a plethora of approaches aiming at modulating STING activation in order to boost or inhibit inflammatory responses. However, recent work has revealed that STING is also a direct regulator of metabolic homeostasis. In particular, STING regulates lipid metabolism directly, a function that is conserved throughout evolution. This indicates that STING targeting strategies must take into consideration potential metabolic side effects that may alter disease course, but also suggests that targeting STING may open the route to novel treatments for metabolic disorders. Here we discuss recent work describing the metabolic function of STING and the implications of these findings.

"You Are Always at War With Yourself" The Perceptions and Beliefs of People With Obesity Regarding Obesity as a Disease

Obesity as a disease remains poorly understood by key stakeholders. Here, in people living with severe obesity, perceptions and beliefs relating to obesity as a disease and obesity causality were examined. Semi-structured interviews were conducted in a tertiary care obesity clinic. 23 people with obesity (10 males, 13 females) volunteered. An overall agreement that obesity is a disease was present. Perceptions related to why obesity is and is not a disease were diverse: Lack of control and addiction, biological determinism, and personal responsibility. For weight loss maintenance, the perceptions and beliefs were heterogeneous with biological factors not considered a determinant of success. Instead, exercise, support, and willpower were described as associated with success. Barriers related to remaining in a weight-reduced state included the following: Emotional eating, sustainability of diet, occupational impact, and defeatism due to misaligned expectation and outcome. In conclusion, people living with obesity tend to agree obesity is a disease yet an incomplete understanding of the disease is present.

Climate Change and Obesity

Global warming and the rising prevalence of obesity are well described challenges of current mankind. Most recently, the COVID-19 pandemic arose as a new challenge. We here attempt to delineate their relationship with each other from our perspective. Global greenhouse gas emissions from the burning of fossil fuels have exponentially increased since 1950. The main contributors to such greenhouse gas emissions are manufacturing and construction, transport, residential, commercial, agriculture, and land use change and forestry, combined with an increasing global population growth from 1 billion in 1800 to 7.8 billion in 2020 along with rising obesity rates since the 1980s. The current Covid-19 pandemic has caused some decline in greenhouse gas emissions by limiting mobility globally via repetitive lockdowns. Following multiple lockdowns, there was further increase in obesity in wealthier populations, malnutrition from hunger in poor populations and death from severe infection with Covid-19 and its virus variants. There is a bidirectional relationship between adiposity and global warming. With rising atmospheric air temperatures, people typically will have less adaptive thermogenesis and become less physically active, while they are producing a higher carbon footprint. To reduce obesity rates, one should be willing to learn more about the environmental impact, how to minimize consumption of energy generating carbon dioxide and other greenhouse gas emissions, and to reduce food waste. Diets lower in meat such as a Mediterranean diet, have been estimated to reduce greenhouse gas emissions by 72%, land use by 58%, and energy consumption by 52%.