Disclosed are ready-to-eat puffed dried food products that are high both in protein and in fiber. A trench isolation film, self-aligned with the gate electrode, is also formed so that the upper surface of the isolation film is higher than that of the gate electrode. Typically, the balloon is formed of a polymer like polyethylene terephthalate. The operating conditions in the process are relatively mild at near ambient pressure and less than 145 C.