I recently attended a presentation by Tim Peake (a UK astronaut) and, as well as the more commonly known issue of reduced sense of taste and smell, the other issue with eating in space is that you quickly feel full as gravity isn't pulling the food down to the bottom of the stomach so triggers the 'full' feeling and you have to get used to ignoring it.

Surprisingly though, you don't need gravity for your body to pull food down to your stomach when you swallow it.