I'm Celiac, so I eat no wheat but rice and corn are pure crap. I grew up on a working ranch and you only feed mammals grain a month before slaughter because it's the equivalent of candy!
When I eat my normal diet of freggies and meats/ fish/ poultry, my body does better. I'm not interested in losing weight but I *have* put on a layer of fat since grabbing these easier foods (rice chex and popcorn are quicker/ less prep than meals--apart from salads, which I'm eating, too! -- whatever's quick with zero time).