Question

Why do we smell hot food from a distance?

Answer 1

Hot Food has high temperature, High temperature means paricles posses high Kinetic energy and hence diffuse faster into air.
So, Due to increase in temperature, Rate of diffusion increases ..

Answer 2

this is due to diffusion
particles of the hot sizzling food diffuses in the air very fastly due to the increase on kinetic enegy and reaches us