When running a restaurant it is traditional to provide staff with a meal at the end of their shift and you may eat with them. In both cases you may need to account for the cost of the food and drink consumed. Feeding the employees is treated differently to the cost of your own food, unless you are also an employee of the company that runs the restaurant. The cost of the staff meals are part of the total welfare cost of employing staff. The meals are a tax free benefit for the staff as long as they eat them in a designated staff area or while the restaurant is closed to customers.
If you run the business in your own name or as a partnership, the value of the food and drink you consume is treated as part of the profits you make from the business. However, the items consumed or taken for your own use should be valued at their cost, not at the price a customer would pay. Tax officers sometimes forget that guidance was issued on this treatment back in 1957, as set out in Statement of Practice A32.