Good food at Smoked Creations north of the river in Ottawa. Take Main Street north and turn right on Logan.
This is a great rail to trail experience! Heading East out of Ottawa, you travel through one small community, Rantoul, which doesn't have any accessible water or support that I saw, so plan ahead for this run if you are going for the whole 18 miles. The feel of this portion of trail and a few miles West of Ottawa is not as secluded and "out in the middle of nowhere" feel as it is West of Osage City.
There are a lot of houses and properties that back up to this section of rail to trail and when you get to Osawatomie (south of 347th St), you'll cross several driveways to homes that I didn't exactly like how close the trail was to the homes, especially if you encounter "protective" dogs. Personally, I would bail out off off the trail at 347th and head East into Osawatomie if you need to find food, etc.
I found a gas station, a couple of local diners and two fast food places at the center of Osawatomie and closer to HWY 169 if you need support.