Homeostasis, Set Point Theory, And The Settling Point Theory
Scientists hypothesized at one point, that body weight and its regulation or rather lack thereof could be explained due to a biological mechanism: Hemostasis. However, as advances in the field and researches were met scientists realized that body regulation was influenced by other factors. These factors contribute to how the human’s body weight is viewed following the theories of Set Point and Settling Point.
Homeostasis, in biology, is described as an overall term; as a tendency of biological systems that maintain equilibrium. This tendency resists change so as to main a stable, relatively constant internal environment in individual organisms to ecological patterns of balance in a community of organisms. Hemostasis is usually compared as a gauge, one that recognizes slight drifts in conditions. For example, one well known in the human body is the body’s ability to regulate its temperature regardless of the stimuli or environmental factors it encounters, ensuring its temperature is always at a constant 98.6 °F (Homeostasis). This concept led scientist to believe that our brain could decide what needed to be done to maintain the human body’s weight steady.
Set point theory, according to Kessler, states that the adult weight is designed to remain at a predetermined level (Kessler, D., 2019). However, it is closely related to a range of possible weights that the body attempts to maintain. Set point hypothesizes that if the human body loses weight, the body itself will try to get it back, slowing down its metabolism until returning to its programmed set point. Yet, this does not translate to the body losing or gaining weight, rather a way to maintain predetermined weight. Scientists have completed studies supporting this theory by “starving” volunteers. These volunteers are then allowed to eat ravenously until their weight returns to its normal level, regardless of the caloric intake.
Settling point theory, this idea is also based on engineering control systems; beyond homeostatic mechanisms asserting that weight is not set at a predetermined level rather determined by unregulated parameters (Speakman et al, 2011). Settling point theory works as both a negative and positive correlation that is: if a person’s physical activity is greater than their caloric intake, they will lose weight. Or if a person’s caloric intake is greater, they will gain weight. Both these cases depend on the factors and unregulated parameters.
Homeostasis and set point theory are similar under the following condition: both principles’ purpose is to regulate and maintain the human body’s weight at a predetermined level by adjusting and creating a balance between consumption and output. Yet, they differ as homeostasis’ ultimate goal is to maintain this balance through biological means, unlike set point which theorizes that a person’s weight has been programmed and destined to remain at a set weight (Richard & Kissey, 1997).
Settling point theory, in comparison to the aforementioned theories, suggests that this model requires a minimum one parameter on the intake or output that is not regulated. In other words, a person’s weight will vary and fluctuate according to a multitude of factors such as eating habits, environmental to include physical activity. For examples, if a subject is allowed to eat as they please, disregarding their normal eating habits, the subject will show an increase in weight and mass at an increasing rate. As previously mentioned, the negative and positive correlations depend on the factors applied to the formula.
In the past scientist were certain that factors and mechanisms controlled an adult human body weight. However, as time has changed and eating habits have deteriorated these hypotheses no longer are true. In previous years, the population was not exposed to foods rich in sugars, fats, and salt as today. These foods are known as palatable; the exposure to palatable foods and the inability of the body to handle, regulate and comprehend these new foods opened the doors to the obesity epidemic. Other factors such as our attitude towards eating homemade meals changed after the appearance of more “convenient” foods, where microwavable meals in front of the TV became the norm; taking the family away from the dining table and changing the dynamics of eating, giving birth to a beast of “eater-tainment” (Kessler, D., 2009).
Initially, scientists believed that the body regulated its weight by means of biological mechanical forces. However, new theories showing studies that as time has passed the ideal of the body regulating its own weight by homeostasis is no longer the case. These theories have brought light on how weight gain and loss is substantially controlled by other means. Set point and settling point theorems have shown that by manipulating these mechanisms weight adjustments are achievable as long as the regulating system is set to maintain.
