What type of diabetes occurs when the body does not produce enough insulin?

Type 1 diabetes occurs when the body does not produce enough insulin due to the autoimmune destruction of insulin-producing beta cells in the pancreas. This condition often manifests in childhood or early adulthood and leads to elevated blood glucose levels because insulin, which is necessary for glucose uptake by cells, is insufficiently produced.

In contrast, type 2 diabetes generally arises from insulin resistance, where the body becomes less responsive to the insulin it produces, rather than an outright lack of insulin production. Gestational diabetes occurs during pregnancy and is characterized by insulin resistance and not a complete lack of insulin. Prediabetes indicates a state where blood glucose levels are higher than normal but not yet high enough for a diabetes diagnosis and does not imply insufficient insulin production per se.

Therefore, the distinction of type 1 diabetes being primarily linked to insufficient insulin production makes it the correct answer in this context.