Answer:
The first part here is to understand what homeostasis means. Homeostasis is defined as the natural balance that the human body keeps by controlling the different factors that make a part of it. This homeostasis is internal and it totally depends on the body´s different mechanisms to maintain a controlled internal system. Homeostatic imbalance appears when at least one of the factors falls out of synchronization, affecting one or more of the systems in the body.
Glucose is an absolutely essential molecule for the body and without it there would simply be no energy; thus without glucose there would be no homeostasis either. The body has two means of acquiring glucose for cellular activities: diet and breaking of stored glucose components in the muscles and the liver. When the body has a low level of blood glucose, the body´s mechanisms will turn on in order to restore the balance, as there must always be a minimum, and maximum, amount of free glucose in the bloodstream. When these mechanisms cannot meet the needs, or when forces out of the body´s control come into play, then we speak of an imbalance, or homeostatic disbalance.
Calvin are a candy bar, which is not just packed with glucose, but also with much more complex sugars that will yield an enormous amount of glucose and fructose to the bloodstream. As such, the peaks of glucose free in the bloodstream will be abnormally high and homeostasis becomes unbalanced. In response to the glucose in the blood, the pancreas begins secreting insulin, the molecule responsible for ensuring that cells are able to capture glucose and fructose, and use them for energy production. Insulin does this by binding to receptors on the cells´ surface to encourage glucose uptake. If the amount of molecules of glucose and fructose are too high, then the body will start to cluster these into glycogen molecules which will then be taken by muscle and the liver to store for when Calvin´s bloodstream glucose levels drop below normal. Like this, Calvin has regained his homeostatic balance after eating the candy bar.