36 research outputs found
Which physical and social environmental factors are most important for adolescents’ cycling for transport? An experimental study using manipulated photographs
How Combined Trip Purposes Are Associated with Transport Choice for Short Distance Trips. Results from a Cross-Sectional Study in the Netherlands
Hydroxyurea therapy contributes to infertility in adult men with sickle cell disease: a review
Effect of Bike Lane Infrastructure Improvements on Ridership in One New Orleans Neighborhood
ADHD, stimulant medication use, and the risk of fracture: a systematic review and meta-analysis
Assessing the market potential of electric bicycles and ICT for low carbon school travel: a case study in the Smart City of ÁGUEDA
Feeding Problems and Nutrient Intake in Children with and without Autism: A Comparative Study
Peripheral Signals Conveying Metabolic Information to the Brain: Short-Term and Long-Term Regulation of Food Intake and Energy Homeostasis
Numerous peripheral signals contribute to the regulation of food intake and energy homeostasis. Mechano- and chemoreceptors signaling the presence and energy density of food in the gastrointestinal (GI) tract contribute to satiety in the immediate postprandial period. Changes in circulating glucose concentrations appear to elicit meal initiation and termination by regulating activity of specific hypothalamic neurons that respond to glucose. Other nutrients (e.g., amino acids and fatty acids) and GI peptide hormones, most notably cholecystokinin, are also involved in short-term regulation of food intake. However, the energy density of food and short-term hormonal signals by themselves are insufficient to produce sustained changes in energy balance and body adiposity. Rather, these signals interact with long-term regulators (i.e., insulin, leptin, and possibly the orexigenic gastric peptide, ghrelin) to maintain energy homeostasis. Insulin and leptin are transported into the brain where they modulate expression of hypothalamic neuropeptides known to regulate feeding behavior and body weight. Circulating insulin and leptin concentrations are proportional to body fat content; however, their secretion and circulating levels are also influenced by recent energy intake and dietary macronutrient content. Insulin and leptin concentrations decrease during fasting and energy-restricted diets, independent of body fat changes, ensuring that feeding is triggered before body energy stores become depleted. Dietary fat and fructose do not stimulate insulin secretion and leptin production. Therefore, attenuated production of insulin and leptin could lead to increased energy intake and contribute to weight gain and obesity during long-term consumption of diets high in fat and/or fructose. Transcription of the leptin gene and leptin secretion are regulated by insulin-mediated increases of glucose utilization and appear to require aerobic metabolism of glucose beyond pyruvate. Other adipocyte-derived hormones and proteins that regulate adipocyte metabolism, including acylation stimulating protein, adiponectin, diacylglycerol acyltransferase, and perilipin, are likely to have significant roles in energy homeostasis