Snails like soft fleshy fruits and softer veggies but they dont like hard to eat foods like carrots. This is mostly because they are veggies that they cannot access due to them being underground. My evidence is that when put into food choosing trials the snails went for the fleshier foods like strawberrys or soft veggies like lettuce in trials of these sorts they almost ALWAYS chose lettuce or strawberrys. Because of this we reason that if you plant theses kind of food you are almost certain to attract snails. Which is good you think their cute but bad if you don't want half eaten lettuce.
Our inaacuracy is that we didn't really have much time to experiment, we tried to give the snails a natural environment and they ended up eating the grass in the tub, and I don't feel like I thought through our experiment enough.