A food slicing machine is provided for slicing food products such as bacon, cheese or cooked meat for sale as groups of slices in separate packs. The food slicing machine includes a cutter for cutting slices from the food product and a controller for controlling the thickness of the slices. The machine cuts slices according to a first value of a slicing parameter until the controller determines when the amount of food product remaining to be sliced in an end portion of the food product is less than a predetermined group weight threshold. The controller causes a slice to be cut according to a second, different value of the slicing parameter from the end portion for addition to an under-weight group of slices, so that its weight at least equals the predetermined group weight threshold.