Eat junk or starve myself until I reach home. ?

I'm watching what I eat and my sis invited us over for dinner. But she didn't cook she just ordered buckets of KFC chicken and fries and served them with sodas. I'm at her house now but I dont want to eat that fatty food. Should I just wait until I get home to eat which is in like 2-3 hours. ( oh yeah I'm hungry now)