semi-skimmed milk for cooking- 7mth

[MakeAnotherCuppa]

hi all i have a 3yr old and 7mth old we started only using semi-skimmed milk from when DD1 turned 2

But just wondered why its suppose to be full fat milk to cook with?? is it just because of the fat?

just made cheese sauce as normal with semi-skimmed and was thinking am ok to cook with it?

They need as much fat as possible at this stage. DD is 8mo and I use full fat for all her things whenever I can, only using semi if I've run out.