People get hungry at their regular meal times because hunger is triggered by learned behaviour. It means that people learn to associate particular times with eating, which triggers their hunger. Another reason people get hungry during regular meal times is to sustain the energy that the body requires, which may have been used before meal times. According to Cronin and Mandich (2015), getting hungry during meal times is explained by classical conditioning, whereby people become conditioned to feel hungry when they are exposed to a conditioned stimulus. In this case, the hunger feeling is a conditioned response to a regular meal time, a conditioned stimulus. Therefore, the evidence supports the explanation about hunger being triggered by learned behaviour.
Two theoretical perspectives that explain the purpose of sleep include inactivity theory and restoration theory. According to inactivity or evolutionary theory, sleep helps in reducing the chances of predation or injury in the dark, which is ideal for evolution and reproduction (Pollak, Thorpy, & Yager, 2010). The theory bases its principles on evolutionary pressure. According to restoration theory, sleep allows the body to repair and replete its cellular components, which play a significant role in biological functions. Inactivity theory has been supported by comparative studies involving different animal species.
The leaky-barrel model is a settling point model that explains eating and body weight. The model posits that it is possible to permanently change body weight by altering factors linked to energy intake and output (Mela & Rogers, 1998). The model has six steps to explain body weight regulation. The first step is the amount of water entering the hose, representing the amount of food available to an individual. The second step is the water pressure at the nozzle, which represents the available food’s incentive value. The third step is the amount of water entering the barrel, representing the amount of energy that a person consumes. The fourth step is the barrel’s water level, which represents body fat level. The fifth step is the amount of water that leaks from the barrel, representing the amount of energy a person expends. The sixth step is the barrel’s weight on the hose, which represents the satiety signal’s strength. The negative feedback model helps explain eating by stating that it turns on when the body requires energy and turns off when the energy set point is attained.
The modern biopsychosocial view of emotions posits that objective emotion components play an essential role in building predictions regarding health and disease (Plutchik & Kellerman, 2014). The model differs from the Cannon-Bard theory of emotion and the James-Lange theory of emotion. Unlike these other theories that rely on subjective aspects of emotion, it relies on objective emotion components. The James-Lange theory of emotion posits that emotions are due to physiological reactions to various events (Plutchik & Kellerman, 2014). External stimulus initiates a physiological response, and a person’s emotional reaction is determined by how they interpret physical reactions. According to the Cannon-Bard theory, people’s emotions are determined by two parts of the brain, which work simultaneously. For instance, the thalamus controls a person’s experience of emotion, while the cortex controls how a person expresses emotion (Plutchik & Kellerman, 2014).
Cronin, A., & Mandich, M. B. (2015). Human development and performance throughout the life span. Boston, MA: Cengage Learning.
Mela, D. J., & Rogers, P. J. (1998). Food, eating and obesity: The psychobiological basis of appetite and weight control. New York: Chapman & Hall.
Plutchik, R., & Kellerman, H. (2014). Theories of emotion. Saint Louis: Elsevier Science.
Pollak, C., Thorpy, M. J., & Yager, J. (2010). The encyclopedia of sleep and sleep disorders. New York: Infobase Pub.