Why does a person with diabetes often lose weight and feel tired?

A person with diabetes often experiences weight loss and fatigue due to their inability to effectively metabolize blood sugar. In diabetes, particularly Type 1, the body does not produce enough insulin to facilitate the uptake of glucose into cells, which is essential for energy production. Even though blood sugar levels may be high, the cells are starved for energy because they cannot access this glucose. This situation leads to a breakdown of fat and muscle for energy, resulting in weight loss.

Moreover, the lack of glucose metabolism means that the body is not efficiently utilizing its primary energy source, leading to feelings of fatigue and tiredness, as the energy needed for daily activities is not being produced. Understanding this mechanism highlights the importance of insulin's role in blood sugar regulation and why impairment in this process can lead to significant physical symptoms in individuals with diabetes.