In industrialized countries acne presents as an epidemic disease of civilization affecting sebaceous follicles of adolescents and young adults, associated with increased body mass index and insulin resistance. "Western style" diet, characterized by high glycaemic load and increased consumption of insulinotropic milk proteins, plays an important role in acne pathogenesis. On the cellular level, nutrient-derived metabolic signals are sensed by the metabolic transcription factor FoxO1 and integrated by the regulatory kinase mTORC1. mTORC1, the central hub of protein- and lipid biosynthesis, cell growth and proliferation, is activated by insulin, IGF-1 and branched-chain essential amino acids, especially leucine. The understanding of Western diet-mediated nutrient signalling with over-activated mTORC1 offers a reasonable approach for dietary intervention in acne by lowering glycaemic load and consumption of milk and milk products. A suitable diet attenuating increased mTORC1 activity is a Palaeolithic-like diet with reduced intake of sugar, hyperglycaemic grains, milk and milk products but enriched consumption of vegetables and fish.