The regulation of appetite and energy balance

Could you elaborate on the physiological processes involved in the regulation of appetite and energy balance, including the roles of hormones like leptin, ghrelin, insulin, and peptide YY? How do signals from the gastrointestinal tract, adipose tissue, and hypothalamus integrate to modulate hunger, satiety, and energy expenditure? Additionally, how do dysregulations in appetite control contribute to obesity, metabolic syndrome, and eating disorders, and what strategies are employed in their treatment and management?