Which of the following is NOT a symptom of diabetes?

Weight gain is not typically classified as a symptom of diabetes. In fact, diabetes—particularly type 1 diabetes and advanced type 2 diabetes—can often lead to weight loss due to the body's inability to properly utilize glucose for energy. In these circumstances, despite increased hunger and food intake (polyphagia), the body starts to break down fat and muscle for energy, which can result in weight loss rather than gain.

On the other hand, the other options—fatigue, polyphagia, and polydipsia—are recognized symptoms of diabetes. Fatigue occurs because the cells are not receiving enough glucose for energy, leading to tiredness. Polyphagia, or excessive hunger, arises as the body signals the need for more fuel that it cannot effectively use. Polydipsia, or increased thirst, is also common as the body attempts to compensate for dehydration often caused by high blood sugar levels resulting in increased urination.