I'm in the food industry, and this pervasive food-cost mentality is one of the things I think people often do unwisely.
Here's a simple example with made-up numbers: The burger ingredients are $2.50 and the burger sells for $10. There's a 25% food cost. The filet of beef tenderloin costs $10 and sells for $25. The food cost is 40%.
Focusing on food cost means the burger is a better item for the restaurant. But I'd take the 40% food cost instead of the 25% food cost and then net $15 instead of $7.50. A percentage means nothing compared to cash in hand. That's nothing groundbreaking to say, but that discrepancy is often lost on food-industry people because they focus too much on the food-cost percentage.