This perpetual drive to eat is periodically suppressed by inhibitory impulses generated by such things as the presence of food in the gastrointestinal tract, the flow of nutrients into blood and other factors. Metabolic demands of people and animals increase with sickness or trauma , often in conjunction with anorexia. Sickness combined with anorexia leads to accelerated starvation. Before going on, take a minute to reflect on observations you have already made about food intake, body weight and similar topics. When it's cold, animals and people eat more than when it's hot.
Children maintain energy balance with wildly varying intakes of food per meal.
These kinds of observations suggest a very complex system in charge of regulating energy balance and body weight. This view derived from classic experiments in which food intake was studied in rats with lesions in various areas of the brain. Subsequent studies showed that, although these hypothalamic centers are clearly very important in controlling hunger and satiety, they don't explain the whole story. This seagull did, the mole tried to tunnel out and they both died. Understanding these factors is of particular importance to clinicians because they can be manipulated to manage anorectic patients.