Optimising the particle size distribution (PSD) in suspensions can produce up to 50-fold reductions in shear viscosity. This facilitates pumping, mixing and transportation in the fuel, concrete, paint and food industries. The present point of focus herein is the application of controlled PSD to influence food processing. An extensive literature details the relationships between PSD and flow rheology for suspensions of model spheres using optimisation of the maximum packing fraction of the particles. For non-spherical particles, which are usually found in industrial processes, literature reports similar behaviour to that observed for model systems. The additional complexity introduced by the particle geometry and the difficulty to obtain monomodal distributions can be solved using experimental evidence and numerical modelling. It is thus clear from literature results that controlling the PSD may be employed to influence food processing optimisation. In addition, the direct applicability of previous studies. such as studies on coal-water slurries, is identified for food.