Dispersed solid particles affect primary crystallization of the continuous fat phase as well as the arrangement of primary fat crystals into networks. Today’s knowledge lacks sufficient information about the development of fat crystal networks in the presence of particles, especially within the meso-scale range (100 nm – 1 μm). Nevertheless, understanding structure development over the whole length scale is crucial in defining technological and sensorial functionalities in complex food systems. Therefore, this research aims at explaining the physical properties of fat-based model suspensions through insights in the fat crystallization at different length scales (from nano- to micro-scale). This research uses a very advanced toolbox comprising ultra-small angle X-ray diffraction (USAXS), synchrotron microbeam X-ray diffraction, Fourier transform infrared, Raman spectroscopy and atomic force microscopy. USAXS allows studying the meso-scale but it has scarcely been used in complex food systems. In this study fat crystallization investigated in model suspensions containing distinct particle types and different types of fat. Furthermore, the influence of shear on fat crystallization in these model suspensions will be investigated. The last part of this study aims at finding relationships between insights in the fat crystallization behavior at the nano-, meso- or micro-scale level and the macroscopic properties of fat-based suspensions.