War on obesity

We, the bellies of the United States of America, need to combat our population's obesity. I propose that we invent a small, taste-rewarding food that expands twice its size in our stomaches when consumed before water (the reactor). The size expansion could be attributed to the creation of air pockets, like bread when it rises, or of a product that reacts similar to helium inflating a balloon, or of something similar to a toy miniature grow creature. Not sure what the end-result (no pun intended) would be with all of that air floating around, but we need to jump on this.