Drinks and french fries represent the largest margins, but profit on other items (in the restaurants I managed) was solid as well. I think the misnomer is that

Drinks and french fries represent the largest margins, but profit on other items (in the restaurants I managed) was solid as well. I think the misnomer is that soft drinks and fries have huge margins, and that foodstuff has standard foodservice margins. Back in the day soft drinks cost ~.15 for a 32oz/1L serving, which sold for ~1.50 (including cup/straw/ice, Canada, 90s). Fry portions (large) were somewhere in the ~.20 range and sold for ~1.80. Burgers were generally 30-40% food costs (and 30-40% overhead). Not as profitable, but far from unprofitable (given the large volume sold).