What type of solutions is starch in water?

Starch is a macromolecular substance that, when mixed with water, forms particles in the colloidal size range.

In this colloidal system, the dispersed phase (starch) has a strong affinity for the dispersion medium (water).

Colloidal solutions in which the particles of the dispersed phase have a strong affinity for the dispersion medium are known as lyophilic sols.

Thus, starch in water is an example of a lyophilic sol.