A method and device for producing knitted fabric include supplying roving to a stretching unit with stretching roller pairs and a spinning nozzle device and drawing the roving using the stretching roller pairs. Inlet and outlet roller pairs of the stretching unit are controllably driven, according to a pattern to be formed on the machine, so that the thread thickness of the drawn roving is varied by changing the relative speed between inlet and outlet roller pairs. The drawn roving is supplied to the spinning nozzle device and strengthened by applying compressed air, and the drawn, strengthened roving is supplied to the machine. The thread supply speed of the drawn, strengthened roving to the machine is set depending on the loop size to be knit by the machine by controlling rotation speed of at least one driven roller of the outlet roller pair. A knitted fabric is also provided.