Remember, cost percentages are a management tool, nothing more, nothing less.
In hindsight, a majority of successful restaurants exhibit the 30-30-30-10 guideline, then again, there are not just aq few that deviate, some fairly widely.
Is a 45% food cost bad or a 20% food cost good? Not necessarily! It depends upon the specific venue, menu, market, etc.
Once management establishes a target percentage, there are numerous ways to meet the target:
- Cut waste
- Change buying sources
- Portion control
- Menu management
- and many others
Remember, as food cost fluctuates, so does labor. Overhead (rent, utilities, insurance, etc.), on the other hand, varies very little, whether there are sales or not.
IMHO, food cost + labor cost = cost of sales. Sales-cost of sales = gross profit. Gross profit - overhead = net profit.