'at lave mad' also means to cook. In this context, 'to cook' would be more appropriate.
I can't imagine an instance where I've ever heard someone speaj of "making food." Making dinner or breakfast perhaps, but not food generically.
One would prepare food or cook it but not make it.
Nej, men jeg bruger maden til at lave gas
You cook/prepare food or you make/prepare dinner - mixing them up means you do not really know your English