Bis‐(2‐ethylhexyl) phthalate (DEHP) is one of the most widely used plasticizers, and human beings are exposed to DEHP via polyvinyl chloride (PVC) materials, medical equipment and even drinking water. While DEHP has been implicated to influence metabolism and endocrine functions, important questions remain about the molecular mechanisms of these effects. We employed the model organism Drosophila melanogaster and examined physiological, molecular and behavioural effects from DEHP‐contaminated food. We found that DEHP, at levels comparable to human exposure, made male flies more resistant to starvation and increased lipid levels, while decreasing circulating carbohydrates. Moreover, DEHP‐fed male flies had higher expression levels of an insulin‐like peptide known to regulate metabolism, as well as the insulin receptor. Our results suggest that long‐term DEHP feeding may induce diabetes‐like dysfunctions. These findings provide a molecular background of how DEHP may have detrimental effects on metabolic functions.