Kava drinker for about 8 years. I would say that generally I have noticed a decrease in appetite, overall. In my mid teenage years I started developing a nocturnal eating pattern, where no matter what I did, I would wake up around 12 - 1am feeling famished, and would sometimes almost sleepwalk to the fridge to eat whatever sounded good to my hungry subconscious. I would later be diagnosed with nocturnal eating syndrome by a professional doctor (which was linked to my anxiety disorder). However, I never do this with kava, never. When I stop drinking kava for a few days or weeks, sure enough, this pattern emerges again.
Other than that interesting anecdote, I would say I eat a whole lot less when I'm drinking kava regularly, and when I do eat it's something that is satisfying and tides me over, rather than snacking and being hungry all day.