Tell me what you eat, and I will tell you what you are.
[Dis-moi ce que tu manges, je te dirai ce que tu es.]
Jean Anthelme Brillat-Savarin (1755-1826) French lawyer, politician, epicure and gastronome
Physiologie du goût, “Aphorismes pour servir de prolégomènes” (1825)
Popularly, "You are what you eat."