IMO, everyone is different and what effects swelling. My wife rarely adds salt to her food and drinks the ships water along with wine. I add salt to everything and drink the ships water, drink wine, beer and sometimes whisky (neat). My wife drinks coffee with breakfast and I never drink coffee. Neither one of us drink soda. She always wears compression socks when flying but not always on the ship or in port. Her ankles always swell and mine never do.