I discovered in college that green food dye in corn bread will slow down a little how fast your room mates will eat the corn bread. Red didn’t work as well.
My fraternity pledge group learned on the morning after Hell Night that creative use of food coloring can really slow down the frat's pancake consumption. Add some unexpected flavoring (like peppermint) and it slows further. We had one holdout through it all, the frat president, but even he folded after being served green orange juice.
(And they thought they'd made the kitchen "safe" before turning us loose to cook their breakfast. Didn't account for the ingenuity of us engineering majors. *\;-)