Not sure about along the path. You’re probably better off waiting till you park the bikes at MD.
MD itself has a nice cafe/restaurant upstairs – but not exactly el cheapo.
If you’re looking for something more greasy spoon, then there’s a hut just a hundred yards or so from MD (towards bridge) that does bacon butties, burgers etc, but you’ll have to eat al fresco. Further beyond there and on the cranes side of the floating harbour, there are loads of cafes, restaurants etc in the new shipping containers type development just after the M-shed. Salt & Malt do excellent (but again, not cheap) fish and chips. Further along again, there’s the famous Brunel Buttery for all kinds of sandwiches and butties – but again, outdoors eating.