If you take antibiotics with food it can affect the absorbancy of the drug. If it not absorbed the body will not recognise it as an antibiotic which can be the same as not completing the course. Your body could become resistant to them. Do not stop start stop start etc. You need to decide how important you feel it is to take them. I dont know your medical history but if you have a sore throat and maybe tonsilitis it will usually clear up on its own without antibiotics. The fact that you are still wanting to eat would suggest it is relatively mild but probably painful. Read the following taken from patient.co.uk, a web site used by NHS direct.
Do I need an antibiotic?
Usually not. Most throat and tonsil infections are caused by viruses, although some are caused by bacteria. Without tests, it is usually not possible to tell if it is a viral or bacterial infection. Antibiotics kill bacteria, but do not kill viruses. However, even if a bacterium is the cause, an antibiotic does not make much difference in most cases. Your immune system usually clears these infections within a few days whether caused by a virus or a bacterium. Also, antibiotics can sometimes cause side-effects such as diarrhoea, feeling sick, rash, and stomach upsets.