Perceived palatability of food controls caloric intake. Sweet taste is the primary means of detecting the carbohydrate content of food. Surprisingly, sweet taste sensitivity is responsive to extrinsic factors like diet, and this occurs by unknown mechanisms. Here, we describe an unbiased proteomic investigation into sweet taste sensitivity in the fruit fly. We identify a dopamine/cyclic AMP (cAMP)/CREB axis acting within sweet taste neurons that controls taste perception but is largely dispensable for acute taste transduction. This pathway modulates sweet taste perception in response to both sensory- and nutrient-restricted diets and converges on PGC1α, a critical regulator of metabolic health and lifespan. By electrophysiology, we found that enhanced sucrose taste sensitivity was the result of heightened sweet taste intensity and that PGC1α was both necessary and sufficient for this effect. Together, we provide the first molecular insight into how diet-induced taste perception is regulated within the sweet taste neuron.