GO:0002021 response to dietary excess: Genes & Methods

Response to dietary excess (GO:0002021) is a biological process defined as the physiological process in which dietary excess is sensed by the central nervous system, resulting in a reduction in food intake and increased energy expenditure. This process is essential for maintaining energy homeostasis when nutrient intake exceeds immediate metabolic needs. It integrates peripheral signals from the gut, adipose tissue, and liver with central neural circuits that control feeding behavior and thermogenesis. Research on this term spans nutrition, neurobiology, endocrinology, and metabolism, with implications for obesity, diabetes, and related metabolic disorders. Dietary protein and gut microbiota composition and function interact to influence host metabolic responses to dietary excess. In infants and young children, complementary feeding practices shape long-term metabolic programming and responses to dietary excess later in life. The low-carbohydrate diet exemplifies how macronutrient manipulation can produce short-term metabolic efficacy but longer-term limitations in sustaining the response to dietary excess. Dietary antioxidants and exercise performance further illustrate how dietary components modulate systemic responses to excess. In weaned piglets, dietary valine and leucine levels affect growth and metabolic responses, providing a translational model for amino acid sensing in dietary excess. Gout research highlights how excess calories, purines, and alcohol intake trigger a urate-lowering diet response, linking dietary excess to inflammatory joint disease. In liver transplant recipients, a blunted inflammatory response is associated with a lower response to a weight-loss dietary intervention, showing that immune status modifies the response to dietary excess. A high-protein diet-responsive gut hormone in Drosophila melanogaster regulates behavioral and metabolic optimization, revealing conserved mechanisms for sensing dietary excess. Together, these studies underscore the importance of GO:0002021 in health and disease.

In our own words, GO:0002021 describes the body's coordinated reaction to consuming more energy or nutrients than it needs. The central nervous system detects this excess through hormonal and nutrient signals, then triggers two main outcomes: eating less and burning more energy. This process is distinct from simple satiety because it specifically addresses the state of dietary excess and aims to restore energy balance. It involves sensing, integration, and effector responses across multiple organs and tissues.

Understanding response to dietary excess is critical because dysregulation of this process underlies the modern epidemic of obesity and metabolic diseases. The central nervous system's ability to sense and respond to dietary excess determines whether an organism maintains energy balance or develops pathological weight gain. Dietary protein and gut microbiota composition and function are key modulators of this response, influencing host metabolism. Complementary feeding practices in early life shape long-term metabolic responses to dietary excess. Low-carbohydrate diets demonstrate that short-term metabolic efficacy can be limited by longer-term adaptations in the response to dietary excess. Dietary antioxidants affect exercise and sports performance, showing that dietary excess responses extend to physical performance. In animal models, dietary valine and leucine levels alter the response to dietary excess, highlighting amino acid sensing. Gout is a direct consequence of excess calories, purines, and alcohol intake, and response to a urate-lowering diet is a clinical manifestation of GO:0002021. In liver transplant recipients, a blunted inflammatory response predicts a lower response to weight-loss dietary intervention, linking immune function to dietary excess responses. A high-protein diet-responsive gut hormone in Drosophila regulates behavioral and metabolic optimization, providing a conserved model for studying GO:0002021. Thus, this process is central to preventive and therapeutic strategies for metabolic diseases.

The following genes and proteins are involved in the sensing, integration, and effector phases of response to dietary excess, based on published literature.

Response to dietary excess is regulated at multiple levels. The central nervous system integrates hormonal signals, including gut hormones that respond to high-protein diets, as shown in Drosophila melanogaster. Dietary protein and gut microbiota composition and function regulate host metabolic responses, with microbial metabolites influencing satiety and energy expenditure. In weaned piglets, dietary valine and leucine levels regulate growth and metabolic responses, indicating amino acid-specific regulation. Inflammatory status regulates the response to weight-loss dietary interventions in liver transplant recipients. Low-carbohydrate diets regulate short-term metabolic efficacy but longer-term limitations suggest adaptive regulation. Complementary feeding in early life regulates long-term metabolic programming. These regulatory mechanisms ensure that the response to dietary excess is appropriately scaled to the degree and duration of excess.

Impaired response to dietary excess is a central feature of obesity and metabolic syndrome. When the central nervous system fails to reduce food intake and increase energy expenditure adequately, excess energy is stored as fat, leading to obesity. Dietary protein and gut microbiota composition and function influence this response, and dysbiosis may exacerbate obesity. Low-carbohydrate diets can produce short-term weight loss but longer-term limitations may reduce effectiveness, highlighting the need for sustainable strategies. In liver transplant recipients, a blunted inflammatory response is associated with a lower response to weight-loss dietary intervention, indicating that inflammation can impair the response to dietary excess. Thus, targeting GO:0002021 is key for obesity management.

Gout is a disease directly linked to dietary excess, particularly excess calories, purines, and alcohol intake. The response to a urate-lowering diet is a clinical manifestation of GO:0002021, as reducing dietary excess lowers urate levels and prevents gout flares. Urate transporters and xanthine oxidase are key molecular players in this response. Understanding how dietary excess is sensed and how it leads to reduced intake and increased excretion can inform dietary recommendations for gout patients.

Complementary feeding of infants and young children 6 to 23 months of age can program long-term responses to dietary excess. Inappropriate complementary feeding practices may impair the development of satiety signaling and energy expenditure mechanisms, increasing the risk of childhood obesity. Thus, early-life nutrition is a critical window for establishing a healthy response to dietary excess.

Dietary antioxidants affect exercise and sports performance, which is related to the response to dietary excess because physical activity increases energy expenditure. Athletes often consume dietary excess to support performance, and the response to this excess involves metabolic and redox adaptations. Understanding GO:0002021 in the context of exercise can optimize nutritional strategies for athletes.

CRISPR-Cas9 knockout models are used to test the causal role of candidate genes in response to dietary excess. For example, knocking out a gut hormone in Drosophila can reveal its role in behavioral and metabolic optimization. In piglets, knockdown of leucine-sensing proteins can elucidate amino acid-specific effects. These models allow researchers to determine whether a gene is necessary for the response to dietary excess.

Metabolic cages, indirect calorimetry, and food intake monitoring are used to measure energy expenditure and food intake in response to dietary excess. These methods can quantify the two main outcomes of GO:0002021: reduced food intake and increased energy expenditure. In liver transplant recipients, weight-loss dietary interventions are monitored to assess response. In gout, urate-lowering diet responses are measured via serum urate levels.

16S rRNA sequencing and metagenomics are used to analyze gut microbiota composition in response to dietary protein and excess. Metabolomics can identify microbial metabolites that influence host satiety and energy metabolism. These methods are essential for understanding how the microbiota modulates GO:0002021.

ELISA and multiplex assays are used to measure gut hormones, inflammatory cytokines, and other signaling molecules in response to dietary excess. For example, a high-protein diet-responsive gut hormone in Drosophila can be quantified. In liver transplant recipients, inflammatory cytokine profiles predict response to weight-loss intervention. These methods link molecular signals to the physiological response.

Researchers studying response to dietary excess-related genes often need to determine whether a candidate gene is causally involved in sensing dietary excess, reducing food intake, or increasing energy expenditure. EDITGENE provides comprehensive CRISPR gene editing services to create precisely tailored cell and animal models for such investigations.

Response to dietary excess (GO:0002021) is a fundamental biological process that integrates nutrient sensing, central nervous system control, and peripheral effector mechanisms to maintain energy balance. Dysregulation of this process contributes to obesity, gout, and metabolic syndrome, making it a critical research area. Studies in model organisms and human populations have identified key roles for gut hormones, amino acid sensors, inflammatory cytokines, and gut microbiota. Early-life nutrition and dietary composition further modulate the response, with long-term consequences. Continued research using CRISPR-based models and multi-omics approaches will deepen our understanding of GO:0002021 and inform therapeutic strategies for metabolic diseases.