The objective of this study was to manufacture an imitation cheese that expands to a crispy product when heated in a microwave oven. Imitation cheese (similar to 18% w/w protein and 60% w/w moisture content) was formulated with varying fat content (10-0%). Fat reduction was achieved by direct replacement with resistant starch to give fat:starch ratios of 1.36, 0.53, 0.3, 0.13, or 0. As fat:starch ratio decreased from 1.36 to 0.13 the degree of expansion did not alter significantly (similar to 100%). However, cheese with no fat exhibited significantly greater expansion (similar to 400%). The force required to puncture the expanded products containing fat was significantly higher than those without fat. Results indicate that imitation cheese containing no fat and functional fibre can be transformed to a crispy product. (C) 2008 Elsevier Ltd. All rights reserved.