During my Kendo training in february 2005 to december 2006 I used to meditate a lot. During our meditation sessions, we were told to think about what we have learned during the practise session at the same time we were meditating.
In the way I have experienced meditation is that meditation calms me down and that the meditation really has a positive effect on myself even when I'm outside the dojo.
Sometimes it can happen things in life which may cause worrying or other things which can affect the stomach, so I believe that meditation is something very positive but it's hard for me to know scientifically how the body benefits from meditation.
Good food is a high priority for me these days and it wouldn't surprise me if actually good food can replace or have the same effect as meditation, but I don't think so. Unlike meditation it is unquestionable that the body works better with good food, though.