Final answer:
Diabetes mellitus is the metabolic disorder caused by either a lack of insulin or resistance to insulin, leading to disturbances in carbohydrate, fat, and protein metabolism and potentially resulting in high blood sugar, malnutrition, and ketoacidosis.
Step-by-step explanation:
A condition defined as a disruption of carbs, fat, and protein metabolism resulting from hyposecretion or inaction of insulin is diabetes mellitus. Diabetes mellitus is a metabolic disorder characterized by high levels of blood glucose due to the body's inability to produce sufficient insulin or to use insulin effectively. This condition can result from the destruction or dysfunction of the beta cells of the pancreas which produce insulin, or from cellular resistance to insulin's effects.
Patients with type 2 diabetes, for example, are described as "starving in a sea of plenty" because, despite having high blood glucose levels, their cells cannot utilize the glucose, leading to energy deprivation and potential malnutrition. Furthermore, the deficiency in effective glucose transport to cells leads to the breakdown of fats, resulting in the overproduction of ketone bodies and causing ketosis or ketoacidosis, which dangerously lowers blood pH.