There are a lot of recipes out there for homemade energy or protein bars, can find lots just by googling, or you can just experiment. I've made a lot of protein bars, never used puffed wheat but does sound doable.
I'd think a bar made to create satiety would need protein and fat, so I'd add that, maybe a puffed wheat version of peanut butter rice krispie bars, only with metamucil instead of marshmallow or sugar, could maybe add brown rice syrup or artificial sweetener. Calories might be higher but then again, I think 180 calories is a lot for a bar that is supposed to be a food supplement or diet aid.
If anyone does this, would you share the recipe?